• TABLE OF CONTENTS
HIDE
 Title Page
 Credits
 Table of Contents
 Foreword
 Production of crotalaria for...
 Value of crotalaria as feed
 General discussion, summary and...
 Acknowledgement
 Literature cited
 Appendix














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 361
Title: Crotalaria for forage
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027282/00001
 Material Information
Title: Crotalaria for forage
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 72 p. : ill. ; 23 cm.
Language: English
Creator: Ritchey, G. E ( George Edgar ), 1888-1960
McKee, Roland
Becker, R. B ( Raymond Brown ), 1892-1989
Neal, W. M ( Wayne Miller ), 1905-
Arnold, P. T. Dix, 1902-
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1941
 Subjects
Subject: Crotalaria -- Florida   ( lcsh )
Legumes as feed   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 70-71.
General Note: Cover title.
General Note: "In cooperation with Bureau of Plant Industry, United States Department of Agriculture."
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00027282
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000924594
oclc - 18230477
notis - AEN5221

Table of Contents
    Title Page
        Page 1
    Credits
        Page 2
    Table of Contents
        Page 3
    Foreword
        Page 4
    Production of crotalaria for forage
        Page 5
        Introduction
            Page 5
        Plan of investigation
            Page 5
        Description of the crotalaria species used in the experiment
            Page 6
            Page 7
            Page 8
            Page 9
            Page 10
            Page 11
            Page 12
            Page 13
            Page 14
            Page 15
            Page 16
            Page 17
        Relative adaptability of certain crotalaria species to grazing
            Page 18
            Page 19
            Page 20
            Page 21
        Cultural studies of crotalaria intermedia
            Page 22
            Page 23
            Page 24
            Page 25
        Relative adaptability of certain crotalarias for hay and silage
            Page 26
            Page 27
            Page 28
            Page 29
            Page 30
            Page 31
            Page 32
    Value of crotalaria as feed
        Page 33
        Introduction
            Page 33
        Review of literature
            Page 33
        Plan of investigation
            Page 33
    General discussion, summary and conclusions
        Page 65
        Discussion of production and feeding of crotalaria
            Page 65
            Page 66
        Experimental results
            Page 34
            Page 35
            Page 36
            Page 37
            Page 38
            Page 39
            Page 40
            Page 41
            Page 42
            Page 43
            Page 44
            Page 45
            Page 46
            Page 47
            Page 48
            Page 49
            Page 50
            Page 51
            Page 52
            Page 53
            Page 54
            Page 55
            Page 56
        Toxicity of certain species of crotalaria
            Page 57
            Page 58
            Page 59
            Page 60
            Page 61
            Page 62
            Page 63
            Page 64
        General summary and conclusions
            Page 67
            Page 68
    Acknowledgement
        Page 69
    Literature cited
        Page 70
        Page 71
    Appendix
        Page 72
Full Text



UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
WILMON NEWELL, Director
GAINESVILLE, FLORIDA
in cooperation with
Bureau of Plant Industry, United States Department of Agriculture
CROTALARIA FOR FORAGE
I. PRODUCTION OF CROTALARIA FOR FORAGE
By GEO. E. RITCHEY and ROLAND McKEE
II. VALUE OF CROTALARIA AS FEED
By R. B. BECKER, WV. M. NEAL and P. D. Dix ARNOLD
III. GENERAL DISCUSSION, SUMMARY AND CONCLUSIONS


Fig. 1.-Cows grazing in the Crotalaria "cafeteria" in which nine species of
Crotalaria were investigated as green forage, in adjacent plots. The cows showed
decided preference for certain species.
Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


Bulletin 361


August, 1941







EXECUTIVE STAFF
John J. Tigert, M. A., LL. D., President
of the University"
Wilmon Newell, D.Sc., Director3
Harold Mowry, M. S. A., Asst. Dir., Res.
W. M. Fifield, M. S., Asst. Dir., Admin.
J. Francis Cooper, M. S. A., Editor3
Clyde Beale, A.B.J., Assistant Editor"
Jefferson Thomas, Assistant. Editor"
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager"
K. H. Graham, Business Managers
Rachel McQuarrie, Accountants

MAIN STATION, GAINESVILLE
AGRONOMY
W. E. Stokes, M.S., Agronomist
W. A. Leukel, Ph.D., Agronomist"
Fred H. Hull, Ph.D., Agronomist
G. E. Ritchey, M.S., Associate'
W. A. Carver, Ph.D., Associate
Roy E. Blaser, M.S., Associate
G. B. Killinger, Ph.D., Associate
John P. Camp, M.S., Assistant
Fred A. Clark, B.S.A., Assistant
ANIMAL INDUSTRY
A. L. Shealey, D.V.M., An. Industrialist'-.
R. B. Becker, Ph.D., Dairy Husbandman"
E. L. Fouts, Ph.D., Dairy Technologist'
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian3
L E. Swanson, D. V. M., Parasitologist
N. R. Mehrhof, M.Agr., Poultry Hush.3
W. M. Neal, Ph.D., Asso. in An. Nutrition
T. R. Freeman, Ph. D., Associate in Dairy
Manufactures
D. J. Smith, B.S.A., Asst. An. Husb."
P. T. Dix Arnold, M.S.A., Asst. Dairy
Husbandman"
L. L. Rusoff, Ph.D., Asst. in An. Nutr.3
L. E. Mull, M. S., Asst. in Dairy Tech.
0. K. Moore, M.S., Asst. Poultry Husb.
ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agr. Economist
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Associate
Max E. Brunk, M.S., Assistant
ECONOMICS, HOME
Ouida D. Abbott, Ph.D., Home Econ.1
Ruth Overstreet, R.N., Assistant
R. B. French, Ph.D., Asso. Chemist
ENTOMOLOGY
J. R. Watson, A.M., Entomologist'
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Hort."
R. J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Horticulturist
J. Carlton Cain, B.S.A., Asst. Hort.
Victor F. Nettles, M.S.A., Asst. Hort.
F. S. Lagasse, Ph.D., Asso. Horticulturist2
H. M. Sell, Ph.D., Asso. Horticulturist2
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist.3
George F. Weber, Ph.D., Plant Path.a
L. 0. Gratz, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Asst. Botanist
SOILS
R. V. Allison, Ph.D., Chemist.,3
Gaylord M. Volk, M.S., Chemist
F. B. Smith, Ph.D., Microbiologists
C. E. Bell, Ph. D., Associate Chemist
J. Russell Henderson, M.S.A., Associates
L. H. Rogers, Ph.D., Asso. Biochemist
H. W. Winsor, B.B.A., Assistant Chemist
Richard A. Carrigan, B.S., Asst. Chemist
Geo. D. Thornton, M.S., Asst. Chemist


BOARD OF CONTROL
H. P. Adair, Chairman, Jacksonville
W. M. Palmer, Ocala
R. H. Gore, Ft. Lauderdale
N. B. Jordan, Quincy
T. T. Scott, Live Oak
J. T. Diamond, Secretary, Tallahassee
BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S. Agron. in Charge
R. R. Kincaid, Ph.D., Asso. Plant Path.
Elliott Whitehurst, B.S.A., Assistant An.
Husbandman
Jesse Reeves, Asst. Agron., Tobacco
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Horticulturist in Chg.
John H. Jeffries, Asst. in Cit. Breeding
Chas. K. Clark, Ph.D., Chemist
V. C. Jamison, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Associate Ento.
F. F Cowart, Ph. D., Asso. Horticulturist
W. W. Lawless, B.S., Asst. Horticulturist
R. K. Voorhees, Ph.D., Asso. Plant Path.
EVERGLADES STA., BELLE GLADE
J. R. Neller, Ph.D., Biochemist in Chg.
J. W. Wilson, Sc. D., Entomologist
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph. D., Sugarcane
Physiologist
G. R. Townsend, Ph.D., Plant Pathologist
R. W. Kidder, M.S., Asst. An. Husb.
W. T. Forsee, Ph.D., Asso. Chemist
B. S. Clayton, B.S.C.E., Drainage En-
gineer'
F. S. Andrews, Ph.D., Asso. Truck Hort.
Rov A. Bair, Ph.D., Asst. Agron.
J. C. Hoffman, M.S., Asst. Hort.
SUB-TROPICAL STA., HOMESTEAD
Geo. D. Ruehle, Ph.D., Plant Pathologist
in Charge
S. J. Lynch, B.S.A., Asst. Horticulturist
E. M. Andersen, Ph.D., Asst. Hort.
W. CENTRAL FLA. STA.,
BROOKSVILLE
W. F. Ward, M.S., Asst. An. Husband-
man in Charge2
RANGE CATTLE STA., WAUCHULA
W. G. Kirk, Ph.D., Animal Husbandman
in Charge
Gilbert A. Tucker, B.S.A., Asst. An. Husb.

FIELD STATIONS
Leesburg
M. N. Walker, Ph.D., Plant Pathologist
in Charge
K. W. Loucks, M.S., Assistant Plant
Pathologist
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
E. N. McCubbin, Ph.D., Asso. Truck
Horticulturist
Monticello
A. M. Phillips, B.S., Asst. Entomologist*
Bradenton
Jos. R. Beckenbach, Ph.D.; Truck Horti-
culturist in Charge
David G. Kelbert, Asst. Plant Pathologist
Sanford
R. W. Ruprecht, Ph.D., Chemist in
Charge, Celery Investigations
W. B. Shippy, Ph.D., Asso. Plant Path.
Lakeland
E. S. Ellison, Meteorologist'

'Head of Department
In cooperation with U. S.
:'Cooperative, other divisions, U. of F.










CONTENTS


PART I. PROI)ICTION OF CROTALARIA

Page
Introduction ......................... 5
Plan of Investigation ................. 5
Description of Crotalaria Species
used in the Experiment. ........ 8
Relative Adaptability of Certain
Crotalaria Species to Grazing .... 18
Plan of Investigation................ 18
Results of Grazing Tests.............. 18
Insects ............................ 21
Summary and Conclusions........... 21
Cultural Studies of Crotalaria intcrmedia 22
Plan of Investigations............... 22
Rate and Method of Seeding ......... 22
Summary and Conclusions........... 25


PART II. VALUE OF CROTALARIA AS
Page
Introduction ......................... 33
Review of Literature ................. 33
Plan of Investigation ................. 33
Experimental Results ................. 34
Palatahility Trials ................. 34
Palatability of Crotalaria as
Green Forage .............. .. 34
Palatability of Crotalaria as Hay.. 35
Relative Palatability of Crotalaria
Silages ............ .......... 38
State of Development of C.
intermedia as It Affects
Palatability of Silage............ 39
Nutrient Value of Crotalaria
inter media ..................... 39
Digestion Trials with Mature
Crotalaria intermedia Hay....... 39
Digestion Trials with Crotalaria
intermnedia Silage ............... 41
Practical Observations with Cows
and Mules ................ ..... 42
Grazing Trials with Native Cows... 42
Maintenance Trials with Dairy Cows 42
Crotalaria intermedia Hay for Mules 43
Cooperative Feeding Trials with
Dairy Cows .................... 44


Page
FOR FORAGE ..................... 5


Relative Adaptability of Certain
Crotalaria Species for Hay
and Silage. ..................... 26

Plan of Investigation........ ........ 26

Results of Field Studies on Hay..... 26

Artificially Dried Hay ............ 26
Naturally Dried Hay ............. 27

Drying in Shock ................ 28

Drying in Swath .............. 29

Summary and Conclusions......... 30

Silage Studies .................... 30

Summary and Conclusions......... 32


Page
FEED ....................... ............ 33


Crotalaria intermedia Silage Versus
No. 1 Green Federal Grade Al-
falfa Hay for Milk Production... 44
Mineral Consumption of Dairy
Cows During Feeding Trials..... 48
Effects of Feeds on Flavor of Milk 48
Ensiling Studies with Crotalarias..... 49
Ensilability of Several Crotalarias
in Laboratory Silos.............. 49
Stage of Development of C. inter-
media as It Affected Palatability,
and Ensilability in the Laboratory
Silos .......................... 52
Efficiency of Concrete Silos....... 53
Densities of Crotalaria Silages, and
Silo Capacity with C. Intermedia
Silage ....................... 54
Toxicity of Certain Species of
Crotalaria ...................... 57
Species Reported in the Literature.. 57
Toxicity of C. spectabilis for Cattle 58
Toxicity of C. spectabilis for Swine 62
Toxicity of C. spectabilis for
Chickens and Game Birds........ 62
Toxicity with Horses and Mules.... 63
Toxicity of Crotalaria retusa....... 63
Isolation of the Toxic Principle .... 63


Page
PART Ill. GENERAL DISCUSSION, SUMMARY AND CONCLUSIONS............ 65


Page
Discussion of Production and
Feeding of Crotalaria.......... 65
General Summary and Conclusions... 67


Acknowledgments ................. .. 69
Literature Cited ................... 70
Appendix .......................... 72









FOREWORD
This bulletin reports results of investigations, initiated in
1930 and conducted cooperatively by the Florida Agricultural
Experiment Station and the Division of Forage Crops and Dis-
eases, Bureau of Plant Industry, United States Department of
Agriculture, in the testing and selection of summer legumes
which might serve as forage crops on the lighter types of soils in
the Southeastern states. Plans for the investigations were pre-
pared jointly by the late Dr. A. J. Pieters and Roland McKee of
the Division and staff members of the Florida Station.
Several species of the genus Crotalaria were used in the tests
since, among the numerous species of this genus which are
adapted to tropical and subtropical regions, it was suggested that
one or more might be found suitable as a feed for livestock.
Prior to 1930 more than 75 Crotalaria species had been tested for
adaptability in the Forage Crops Nursery of the Station, coopera-
tively with the Department, and two species C. striata and C. spec-
tabilis, had become widely planted as cover crops in fields and
groves in the Southeast following their release in 1925. Isolated
instances were known where C. striata had been grazed, but pre-
vious investigations of the crotalarias as forage crops had been
limited to a single feeding trial of C. striata at the Florida Sta-
tion (27)'.
Agronomic phases were conducted jointly by the Division of
Forage Crops and Diseases, USDA, and the Agronomy Depayt-
ment, Florida Agricultural Experiment Station. The Depart-
ment of Animal Industry of the Station was responsible for those
phases involving livestock. Duties of the staffs necessarily over-
lapped in the grazing and palatability trials, but all forages used
in the project were provided by the agronomists.

HAROLD MOWRY,
Assistant Director

'Italic figures in parantheses refer to "Literature Cited" in the back of this
bulletin.









CROTALARIA FOR FORAGE

Part I. Production of Crotalaria for Forage

GEO. E. RITCHEY and ROLAND McKEE

INTRODUCTION
Few legumes are grown in Florida which are adapted to
hay production on the light, sandy soils so common in the state.
A limited number of cowpea varieties may be grown profitably
on the better types of soils and farmers occasionally grow soy-
beans for hay in western Florida. A legume is needed which
will grow on the sandy soils, and which may be used for hay and
silage. The value of a crop for these uses depends upon a num-
ber of factors, chief of which are ease and economy of produc-
tion, yield, palatability, nutritive value, and lack of toxicity to
animals. Some species of Crotalaria have given indications of
possible value in this connection.
Crotalaria spectabilis and Crotalaria striata DC. are being exten-
sively grown as cover crops in the Southeastern states. Their
growth habits, culture requirements, and general characteristics
are well known in this section of the country. Little, however,
had been learned of the possibilities of the other species of the
genus. Those species that were being studied in the forage crop
nurseries and which exhibited characters suggesting the possi-
bility of their use for forage, were planted in the field and stud-
ied as possible grazing, hay and silage crops. The forage result-
ing was used by the Department of Animal Industry, Florida
Agricultural Experiment Station, in feeding trials with cattle
and mules, and the relative value of the species determined.

PLAN OF INVESTIGATION
The several Crotalaria species which had been under ob-
servation at the Florida Station, and had shown characteristics
which should adapt them to a forage program, were used in
grazing tests. These grazing tests were followed by palatability
trials with hay and silage. Growth habits of each species, palat-

"Associate Agronomist, Bureau of Plant Industry, U.S.D.A. and Florida Experi-
ment Station; and Senior Agronomist, Bureau of Plant Industry, U.S.D.A., respec-
tively.









CROTALARIA FOR FORAGE

Part I. Production of Crotalaria for Forage

GEO. E. RITCHEY and ROLAND McKEE

INTRODUCTION
Few legumes are grown in Florida which are adapted to
hay production on the light, sandy soils so common in the state.
A limited number of cowpea varieties may be grown profitably
on the better types of soils and farmers occasionally grow soy-
beans for hay in western Florida. A legume is needed which
will grow on the sandy soils, and which may be used for hay and
silage. The value of a crop for these uses depends upon a num-
ber of factors, chief of which are ease and economy of produc-
tion, yield, palatability, nutritive value, and lack of toxicity to
animals. Some species of Crotalaria have given indications of
possible value in this connection.
Crotalaria spectabilis and Crotalaria striata DC. are being exten-
sively grown as cover crops in the Southeastern states. Their
growth habits, culture requirements, and general characteristics
are well known in this section of the country. Little, however,
had been learned of the possibilities of the other species of the
genus. Those species that were being studied in the forage crop
nurseries and which exhibited characters suggesting the possi-
bility of their use for forage, were planted in the field and stud-
ied as possible grazing, hay and silage crops. The forage result-
ing was used by the Department of Animal Industry, Florida
Agricultural Experiment Station, in feeding trials with cattle
and mules, and the relative value of the species determined.

PLAN OF INVESTIGATION
The several Crotalaria species which had been under ob-
servation at the Florida Station, and had shown characteristics
which should adapt them to a forage program, were used in
grazing tests. These grazing tests were followed by palatability
trials with hay and silage. Growth habits of each species, palat-

"Associate Agronomist, Bureau of Plant Industry, U.S.D.A. and Florida Experi-
ment Station; and Senior Agronomist, Bureau of Plant Industry, U.S.D.A., respec-
tively.









CROTALARIA FOR FORAGE

Part I. Production of Crotalaria for Forage

GEO. E. RITCHEY and ROLAND McKEE

INTRODUCTION
Few legumes are grown in Florida which are adapted to
hay production on the light, sandy soils so common in the state.
A limited number of cowpea varieties may be grown profitably
on the better types of soils and farmers occasionally grow soy-
beans for hay in western Florida. A legume is needed which
will grow on the sandy soils, and which may be used for hay and
silage. The value of a crop for these uses depends upon a num-
ber of factors, chief of which are ease and economy of produc-
tion, yield, palatability, nutritive value, and lack of toxicity to
animals. Some species of Crotalaria have given indications of
possible value in this connection.
Crotalaria spectabilis and Crotalaria striata DC. are being exten-
sively grown as cover crops in the Southeastern states. Their
growth habits, culture requirements, and general characteristics
are well known in this section of the country. Little, however,
had been learned of the possibilities of the other species of the
genus. Those species that were being studied in the forage crop
nurseries and which exhibited characters suggesting the possi-
bility of their use for forage, were planted in the field and stud-
ied as possible grazing, hay and silage crops. The forage result-
ing was used by the Department of Animal Industry, Florida
Agricultural Experiment Station, in feeding trials with cattle
and mules, and the relative value of the species determined.

PLAN OF INVESTIGATION
The several Crotalaria species which had been under ob-
servation at the Florida Station, and had shown characteristics
which should adapt them to a forage program, were used in
grazing tests. These grazing tests were followed by palatability
trials with hay and silage. Growth habits of each species, palat-

"Associate Agronomist, Bureau of Plant Industry, U.S.D.A. and Florida Experi-
ment Station; and Senior Agronomist, Bureau of Plant Industry, U.S.D.A., respec-
tively.







Florida Agricultural Experiment Station


ability, possible toxicity, and other characteristics bearing upon
the value of the plant as a forage crop were recorded, and are
considered in Part I of this bulletin. From the results of these
tests, the species best adapted to forage for animals were se-
lected.
The species used in the investigations were: Crotalaria
anagyroides H. B. K.; Crotalaria grantiana Harvey; Crotalaria goreensis
Guill. and Perr.; Crotalaria incana L.; Crotalaria intermedia Kotschy;
Crotalaria lanceolata E. Mey.; Crotalaria maxillaris Klotzsch; Crotalaria
retusa L.; Crotalaria spectabilis Roth; Crotalaria striata DC.; and Cro-
talaria usaramoensis Baker.

DESCRIPTION OF THE CROTALARIA SPECIES USED IN THE
EXPERIMENT3
"Crotalaria anagyroides H. B. K. Plant erect, large, attaining a height of 3
meters; stems well branched, finely pubescent on young growth, becoming woody
with age; stipules none; leaves trifoliolate; leaflets large, 10 cm. long by 3/2 cm.
wide, oval, tending to be pointed at both ends, little or no pubescence; flowers large,
20 mm. long, yellow, clustered in terminal and lateral racemes, quite showy; calyx
tube 5 mm. long; calyx teeth 5 mm. long; pod with short appressed pubescene,
tending to cylindrical, inflated, 30-35 mm. long; seed midlarge, 4-6 mm. long, light
color, greenish brown to yellowish brown, matures late."
Crotalaria anagyroides, a perennial native of India, grows to a
height of from 10 to 12 feet. It produces an abundant growth of
foliage which remains green during the entire growing season
and throughout the milder winters. At Gainesville, Florida, the
plants when frozen above the ground will come back from un-
derground buds in the spring and make an abundant growth the
next season. The second season's growth will bloom by May
and ripen seed in July or August, while seedlings seldom bloom
before August or September. The stems become large (several
inches in diameter) and very woody, especially in the lower part.
In 1933 it was necessary to cut the plants 18 to 24 inches
above the ground and use only the top parts in order to obtain
material which could be run through a silage cutter. The plant
is not relished by stock, although they will eat it after they have
been confined in a field of it for a few days. No toxic properties
have been detected. Seed production is very scant, therefore its
use must be limited.
The plant produces showy bunches of yellow flowers which,
with its symmetrical appearance, makes it valuable as a late
summer and fall hedge. This species is illustrated in Figure 2.

'Botanical descriptions here used are quoted from McKee and Enlow (19).







Crotalaria for Forage


-6'~


~F-'fCf~L~iA


Vp^

e^**^T+
V"t c 9. -


Fig. 2.-Crotalaria anagyroides in the bud stage of development.


"Crotalaria goreensis Guill. and Perr. Plant erect, 9-18 decimeters high, mod-
erately branched, many leaves on main stem which with the large stipules make it ap-
pear quite leafy; stems finely pubescent and lightly sulcate; leaves trifoliolate, the cen-
tral leaflet longer than the laterals, and linear to linear oblong or linear obovate, up to
4-6 cm. long and 1-2 cm. wide, glabrous above, sparingly short pubescent beneath;
stipules foliaceous, acuminate, 1.5 cm. long; flowers few in lateral capitate racemes
or many in dense terminal racemes; calyx finely pubescent, broadly campanulate, 4
mm. long, the wide acuminate teeth about equaling the tube; corolla 10-12 mm.
long, yellow with considerable rose red on standard and wings; pod oval, 17 mm.
long; seed 3.5 mm. long, reddish brown, matures very late."
Crotalaria goreensis:- This species, a native of tropical Africa,
is a rapidly growing leafy perennial. The plant branches pro-







Florida Agricultural Experiment Station


fusely with a tuft of leaves occurring in each axis along the stem.
The seedpods are borne in dense racemes on the branch term-
inals. It is seldom that seed ripens as far north as Gainesville,
inasmuch as it requires a long season to reach maturity. The
general characteristics of the plant are shown in Figure 3.
"Crotalaria grantiana Harvey. Plant erect, 6-9 decimeters high and ramosely
branched, making it dense and bushy; stems finely pubescent; stipules very small;
leaves trifoliolate; leaflets cuneate obovate, 10-20 mm. long and 4-8 mm. wide, upper
side glabrous, lower side pubescent; flowers yellow, 7-9 mm. long, 1 or 2 in axils
of the leaves or 3-5 in terminal lax racemes, outside of standard pubescent; calyx
tube 3 mm. long, calyx teeth 2 mm. long; pod small, 9-11 mm. long, finely pubes-
cent; seed small, 2 mm. long, brown, mature midlate."
Crotalaria grantiana, an annual introduced from r rica in 1911,
is possibly a native of the West Indies. It has fine leaves and
stems; grows to a height of from 2 to 3 feet; produces abundant
leafage, and in some ways resembles alfalfa in appearance. It
seeds well and volunteers nicely after a seed crop has been pro-
duced on the field the preceding year. The pods do not dehisce
readily, but cling to the plant intact for a considerable time after
ripening. The plants can be cut and the seeds threshed by ma-
chine, avoiding the necessity of hand picking. This species has
some desirable characteristics which could contribute to make it
a valuable crop. Its leafiness and fine stems are shown in Fig. 4.
"Crotalaria incana L. Plant erect, 6-18 decimeters high, divaricately branched,
but forming a rather bushy plant; stems clothed in fine silky hairs; stipules very

Fig. 3.-A field of Crotalaria goreensis in the pod stage growing on deep
Norfolk fine sand.







Crotalaria for Forage


Fig. 4.-A single plant of Crotalaria grantiana in the early pod stage.

small; leaves trifoliolate; leaflets broadly obovate to nearly oval, up to 3-4 cm. long,
2-2.5 cm. broad, glabrous above, sparse silky pubescence beneath; flowers yellow, 15
mm. long, about half again as long as the calyx; calyx teeth about three times as
long as calyx tube; pod linear oblong, 32-33 mm. long and 8-10 mm. wide, turgid,
clothed with spreading hairs; seed large, 4.5 mm. long, greenish brown to dark
brown; matures midearly."
Crotalaria incana, a perennial introduced into America in 1911,
is possibly a native of the West Indies. It is a bushy shrub
which grows 5 to 61/2 feet tall at Gainesville, as shown in Fig. 5.
The leaves are numerous during early growth, but tend to fall
from the lower limbs early in the season. The tender portions of
the plant are palatable to cattle as fresh forage and hay. How-
ever, the stems become hard and woody in early summer. It
seeds readily at Gainesville, but often is infested with pumpkin
bugs and the bella moth, which cause considerable injury to the
seed by the time of harvest.
"Crotalaria intermedia Kotschy. Plant erect, 9-18 decimeters high, moderately
branched, stems terete, subglabrous; stipules wanting; leaves trifoliate; leaflets
linear, glabrous above, subglabrous below; 8-14 cm. long, and 1-1.5 cm. wide;







Florida Agricultural Experiment Station


Fig. 5.-Crotalaria incana in the pre-bud stage.

racemes lax, terminal, 15-30 cm. long; flowers up to 2 cm. long, yellow, standard
conspicuously veined with purple; calyx 5 mm. long, broadly campanulate, sub-
glabrous; calyx teeth shorter than the tube; pod large, 5 cm. long, 1.5 cm. broad,
inflated, little or no pubescence; seed 3 mm. long, mostly very light color, matures
midlate."
Crotalaria intermedia was introduced from South Africa in
1924. It is an upright annual which grows well on the sandy
soils of the coastal plains. The plant grows to a height of 6 to 7
feet and produces an abundance of foliage. The leaves, unlike
other species, have a sweet taste. It is reasonably palatable to
cattle when used as a grazing crop or when made into hay or
silage. The plants branch well but the stems have a tendency to







Crotalaria for Forage


become tough and woody as maturity progresses. It blooms in
late August and September and ripens an abundance of seed in
October in the locality of Gainesville. The seeding habits of the
plant are good (Figs. 6 and 7). The characteristics of the plant
at the bloom stage are shown in Fig. 6, while the pods may be
seen in Fig. 7.

"Crotalaria lanceolata E. Mey. Plant erect, 7-12 decimeters high, well branched;
stems small, terete; leaves trifoliolate; leaflets linear, 4-8 cm. long, 6-8 mm. wide,
tip obtuse or rounded, mucronate, glabrous above, sparingly pubescent beneath;
stipules none; flowers in long terminal racemes; calyx tube broadly campanulate, 3
mm. long, lightly pubescent; calyx teeth acuminate, 2 mm. long; corolla 9 mm. long.
yellow, standard and wings striate with purple lines; pod cylindrical, 3 cm. long,
finely pubescent; seed 2.5-3 mm. long, light or reddish brown, matures midearly."


Fig. 6.-Crotalaria intermedia in the blooming stage.







12 Florida Agricultural Experiment Station

Crotalaria lanceolata, a native of South Africa, is a perennial
which grows 4 to 5 feet in height. It produces an abundance of
leaves, and is finer stemmed than other commonly grown spec-
ies. It produces an abundance of seed and re-establishes itself
readily from the previous year's seeding. For these reasons it
promises to be a valuable green manure crop. The seeds ripen
in August and September in pods which do not dehisce readily.
Seed harvest may extend over a long period with little loss. The
shape of the leaf is shown in Fig. 8 and the color and shape of
seed resemble those of Crotalaria intermedia.
"Crotalaria maxillaris Klotzsch. Plant erect, 6-10 decimeters high, with long
suberect branches; young stems finely pubescent; stipules small, setaceous; leaves
trifoliolate; the central leaflet larger than the laterals and about 3.5 cm. long and 1.5
cm. broad; apex rounded, glabrous above, short, sparse pubescent below; flowers
in lax terminal racemes, 15-30 cm. long; calyx 5-7 mm. long, teeth lanceolate,
cuspidate, reaching more than half way down; corolla yellow, 18 mm. long, standard
lightly striated and silky outside; pod subsessile, 12-18 mm. long and 6-10 mm.
wide, finely pubescent; seed nearly 3 mm. long variable brown, matures midlate."
Crotalaria maxillaris, a species from tropical Africa, grows into
a plant about 3 feet tall. The leaves are small and do not form
a heavy foliage except on land especially adapted to its growth.
The leaves have a tendency to drop early. The plant which is
an annual blooms about the middle of August and ripens seed
early in October. Cattle graze it readily. Due to scantiness of

Fig. 7.-Crotalaria intermedia showing the pods after most of the leaves have
dropped.







Crotalaria for Forage 13















N..L

























Fig. 8.-Crotalaria lanceolata growing in the nursery at Gainesville, Florida.

leaf and the tendency of the stems to become woody early in the
season, Crotalaria maxillaris does not have promise as a practical
forage crop.
"Crotalaria retusa L. Plant erect, 3-6 decimeters high, sparingly or moderately
branched; branches divaricate; stems terete, with fine grayish pubescence; stipules
small, setaceous; leaves simple, oblanceolate to obovate; 6-12 cm. long and 2-6 cm.
wide, sessile, glabrous above, very fine pubescence beneath; flowers in lax terminal
racemes, 15-20 cm. long; calyx 1.5 cm. long, the broad teeth exceeding the tube;
corolla yellow, standard 2.5 cm. long, with purplish tinge, exceeding the calyx; pod
linear oblong, 4 cm. long, 1 cm. wide, glabrous, turning black in weathering; seed
large, 4-5 mm. long, light brown to almost black, matures in midseason."
Crotalaria retusa was introduced into America from Brazil in







Florida Agricultural Experiment Station


1913. However, it is a native of South Africa. It grows to a
height of 2 to 3 feet, but does not produce a heavy foliage. The
flowers are showy, as shown in Fig. 9, and are often used as or-
namentals.
"Crotalaria spectabilis Roth. Plant erect, 1-2 meters high, moderately branched,
but heavy foliage makes plant appear dense; branches terete, sulcate, nearly glabrous,
never woody; stipules large, 2 cm. long, foliaceous; leaves simple, large, long obovate,
12-18 cm. long and 6-9 cm. wide, glabrous above, finely pubescent beneath; racemes
mostly terminal, 20-30 cm. long, lax, 30-40 flowered; calyx 12 mm. long, campanulate,


Fig. 9.-A single plant of Crotalaria retusa in the pod stage.








Crotalaria for Forage


teeth broad and as long as the tube; corolla 24 mm. long, yellow with purple tinge,
standard and wings striate with light purple lines; pod 4-5 cm. long, 12-15 mm.
wide, inflated, glabrous, becoming almost black with weathering; seed large, 5 mm.
long, glossy black, matures midlate."
Crotalaria spectabilis, which had its origin in India, is one of the
two species grown extensively in the Southeastern states as a
cover crop. It grows to a height of 6 to 7 feet, and is monofoliol-
ate, having a large single leaflet. It is a perennial which blooms
in August and September, and usually ripens seed in October
and November. The crop reseeds readily. As will be noted later
in this bulletin, C. spectabilis has been found toxic to domestic
animals and fowls. A typical plant is shown in Fig. 10.
"Crotalaria striata DC. Plant erect, 3-18 decimeters high, freely branched, with
branches often quite divaricate, plants not symmetrical; stems terete, becoming
woody with age; the young branches with a fine gray pubescence; stipules minute,
mostly deciduous; leaves trifoliolate; leaflets obovate oblong, glabrous above and
below, 5-8 cm. long and 3-3.5 cm. broad; racemes terminal, moderately dense,
15-25 cm. long; calyx 6-7 mm. long, teeth equaling the tube; corolla yellow,


Fig. 10.-Crotalaria spectabilis in the pod stage.







16 Florida Agricultural Experiment Station

12-14 mm. long; the standard distinctly striate with purple lines; pod up to 4 cm.
long and 8 mm. wide, glabrescent; seed 2.5-3 mm. long, mottled or sometimes solid;
light amber or brown, variable, mature mideason to late."
Crotalaria striata is the species that was first used commercial-
ly in the United States. McKee and Enlow (19) state, "The large
acreage plantings of crotalaria in the Southern states have been
of this species." Crotalaria striata is an erect growing plant branch-











Tl ". r
I V I f
r^W^ ^ f
ryW^r_ i t^ 3^ "


Fig. 11.-Crotalaria striata showing the trifoloate type of leaf, numerous
branches and terminal flower spikes which are characteristic of the species.




























Fig. 12.-A field of Crotalaria tsaramtoensis in bloom.

ing eely in thin stands and making a heavy yield of green
manure. Although it becomes coarse and woody with maturity,
it can be cut with an ordinary mower. When grown in thick
stands and cut in the bloom stage, it has the fineness and leafi-
ness of good hay. In the green state it has a slightly bitter taste
and its value for forage has not been fully demonstrated. Ground
hay from this species was fed to dairy cows in a single trial (27,
Part II). It is considered a good summer cover crop. This species
has fairly good seed habits. At Gainesville it has bloomed in July,
matured seed in August, and continued to bloom and ripen seed
until frost. The grazing of this species by cattle has been re-
ported from various parts of the state. The general characteris-
tics of a vigorous young plant are shown in Fig. 11.
"Crotalaria usaramoensis Baker. Plant erect, 1-2 meters high, well branched;
stems terete, lightly pubescent, woody with age; stipules very small; leaves trifol-
iolate; leaflets linear oblong, 5-10 cm. long and 1.5-4 cm. wide, apex subacuminate and
base cuneate, glabrous above and below; flowers in long terminal racemes; calyx
glabrous, tube 3.5 mm. long, truncate at base, teeth 1.5 mm. long; corolla yellow,
standard 10-13 mm. long, striate with light purple lines, carina slightly longer than
the standard; pod oblong cylindrical. 3.5 cm. long and 8 mm. wide, becoming black
on weathering; seed small, 2 mm. long, amber to red, matures midlate."
Crotalaria usaramoensis, an East African species, is a bushy
perennial, which has not been grown as a cover crop due to its
lack of abundant seeding. While it does not seed sufficiently to
make it a profitable crop, it produces an abundant growth
which is well covered with foliage. The flowers are produced in
long showy spikes, making it a desirable ornamental for late
summer and autumn hedge. See Fig. 12.







Florida Agricultural Experiment Station


RELATIVE ADAPTABILITY OF CERTAIN CROTALARIA
SPECIES TO GRAZING
PLAN OF INVESTIGATION
Ten species of Crotalaria were planted in duplicated plots of
2 or 3 rows each, so distributed over a one-acre field as to bring
the several different species into proximity. This arrangement
was intended to avoid any possibility of influencing the animals'
choice of a species.
Scarified seed was drilled in rows five feet apart, allowing
about the same number of seeds per foot of row. An approxi-
mately uniform stand was obtained.
The arrangement of plots, the stand of forage, and grazing of
Crotalaria intermedia in preference to adjoining plots are shown in
Figure 1.
The following nine species were used in 1931: Crotalaria
grantiana; C. incana; C. intermedia; C. lanceolata; C. maxillaris; C.
retusa; C. spectabilis; C. striata; and C. usaramoensis.
Inasmuch as C. retusa produced little growth, was scanty of
leaf and unpalatable, it was omitted in 1932, and C. anagyroides
was substituted in its place. Thus a total of 10 species was used
in the palatability trials with fresh forage.
The field was cultivated similar to corn in order to keep
down grasses and weeds.
In 1931 two dry dairy cows were grazed on the area in three
periods. The first period began on July 8, the second on July 28,
and the third on September 14. In 1932 the main grazing per-
iods began on June 18, July 28, and October 4.
The cows were given free access to the field, with an oppor-
tunity to graze each species at will. Lineal measurements were
made daily of all rows grazed, and the relative palatability of
the species in each case was estimated to be in proportion to the
amount grazed and the closeness of grazing.
RESULTS OF GRAZING TESTS
Palatability.-The heaviest grazing occurred on the Crotalaria
incana (Table 1), there being 4,550 feet of row grazed. This was
followed closely by Crotalaria intermedia, of which 4,369 feet were
grazed. There was considerable variation in the readiness with
which different animals selected each species. In 1931 the ani-
mals in the second and third groups grazed the entire area of






Crotalaria for Forage


C. maxillaris while the first group in 1931 and all three groups
used in 1932 refused it almost entirely. The leaves of C.
spectabilis, eaten only by the third group (September 14 to 28,
1931), suggest that it may become more palatable in the later
stages of growth. Parallel observations have been made by the
authors under other conditions both in Station plantings and else-
where. Crotalaria lanceolata also was eaten, largely at the end of
the season in 1932. In this case only one cow was observed to
eat the seedpods and very little of the foliage.
Crotalaria incana was grazed consistently by all groups of cat-
tle used in the trials. This species was the first to be grazed by
each group of cattle. No other species was grazed materially
until all leaves and tender stems had been eaten from the
C. incana plots. For this reason, coupled with the fact that more
lineal feet of C. incana were grazed than of other species (see
Table 1), it must be concluded that C. incana was the most palat-
able as a grazing crop.
Crotalaria intermedia, which followed C. incana closely in the
number of feet of row grazed, ranked a close second in the order
of grazing. With the exception of the second group in 1931,
cows began grazing C. intermedia shortly before they had com-
pleted C. incana. On this basis it was concluded that C. intermedia
ranked second in palatability.
Crotalaria anagyroides, used only in 1932, ranked third in palat-
ability for cattle.
In the length of row grazed in 1931, C. maxillaris ranked first;
however, only 3 feet of C. maxillaris were grazed in 1932. The oth-
er species grazed were C. lanceolata, C. usaramoensis, and C. spectabilis
in the order named. Scarcely enough was grazed of any of them
to indicate a difference in order of preference. Crotalaria retusa
and C. striata were not eaten by any of the cows.
Recovery After Grazing.-As soon as the first group of cows
in 1932 had been removed from the field on July 2, one-half of all
rows was mowed at a height of approximately 18 inches. No
further grazing was done until August 13, at which time all
species had produced new growth sufficient to cover the old
growth.
By the time the cows were placed in the field on August 13
new growth on the mowed rows was nearly as large as the plants
which had not been mowed. Crotalaria lanceolata grew back most







20 Florida Agricultural Experiment Station

TABLE 1.-NUMBER OF LINEAL FEET OF 10 CROTALARIA SPECIES GRAZED BY CATTLE
IN PALATABILITY TRIALS, 1931 AND 1932.

SPerioda Rank as
Species Year First Second Third Total to Palat-
(ft.) (ftt.) (f.) ability

C. anagyroides* 1932 61 935 735 1731 3

C. grantiana 1931 0 377 0 377
1933 0 0 0 0 7

C. incana 1931 316 168 316 800
1932 1250 1250 1250 3750 1
C. intermedia 1931 693 0 317 1009
1932 1115 995 1250 3360 2

C. lanceolata 1931 0 0 0 0
1932 62 3 980 1045 5

C. maxillaris 1931 0 1250 1250 2500
1932 0 3 0 3 4
C. retusa 1931 0 0 0 0 0**

C. spectabilis 1931 0 0 219 219
1932 0 0 0 0 8

C. striata 1931 0 0 0 0
1932 0 0 0 0 0**

C. usaramoensis 1931 0 0 0 0
1932 161 0 585 746 6




*C. anagyroides and C. retusa each were used in the trials one year only.
**C. retusa and C. striata were not grazed, hence no rank was assigned.

rapidly. The second growth with C. incana was produced on the up-
per part of the plant, while C. spectabilis and C. anagyroides grew
largely laterally. C. intermedia produced good growth although
not as heavy as the other species just mentioned. C. usaramoensis
came back readily, though the grazing on it by the third group
of cows was confined almost entirely to the plants which had
not been cut back.

One-half of the part of each row mowed on July 2 was again
mowed as soon as the second group of cows was removed from
the pasture on July 27. By the time the third group was put
onto the field on October 4, all species had produced a good new
growth. C. usaramoensis had produced the heaviest growth; C.







Crotalaria for Forage


spectabilis, C. anagyroides, C. striata, C. intermedia, and C. lanceolata
had grown enough to cover the old portions of the plant. The
rows of C. maxillaris did not make recovery after the last mow-
ing.
The last period of grazing in 1932 began on October 4.
C. incana was grazed quite closely. C. intermedia, was grazed so
closely by the third group of cows that no new growth appeared.
The unmowed portion of C. usaramoensis was grazed lightly; that
mowed once was grazed well; and that mowed the second time
was grazed completely. C. grantiana made good recovery and
seeded well.
C. incana ranked first among the species used in this test, as
measured by the amount of foliage consumed, the readiness with
which the cows grazed it, and by the rapidity of growth after re-
moval of a portion of the top. C. intermedia followed as a close
second. On the basis of one year's observations, C. anagyroides
ranked a close third.
INSECTS
All species used in the trial were observed closely to deter-
mine the extent of insect injury. Crotalaria incana produced an
abundance of seedpods but was infested by the pumpkin bug
(Nezara viridula) and the bella moth (Utethesia bella) so severely
that the majority of the seeds were destroyed before maturing.
All other species used in the trials were practically free from in-
sect injuries.
SUMMARY AND CONCLUSIONS
Nine species of crotalarias were offered to dairy cows in a
"pasture cafeteria" two years in succession and observations
were made as to the readiness with which the cows grazed each
species. The recovery of the different species after grazing, and
the extent of insect injury of each species were observed.
The leaves and tender stems of Crotalaria incana were grazed
most consistently by the cows. It made a good recovery after
grazing, and produced a fair yield of forage. This species, how-
ever, became woody and dropped its leaves early in the season.
An abundance of seedpods was produced, which were subject to
attacks by insects which destroyed the seed. C. incana was not
considered desirable as a forage crop, since such a crop should
produce an abundance of leaves and tender stems and sufficient
seed for propagation purposes.







22 Florida Agricultural Experiment Station

Crotalaria intermedia, which ranked second in palatability, pro-
duced an abundant foliage, held the leaves until late in the sea-
son, was reasonably free from insects of all kinds, and produced
a seed crop of good quality which ripened well before the earliest
frost. The stems became woody when in bloom, but appeared less
fibrous than those of C. incana. Inasmuch as no other Crotalaria
species possessed the combined qualities of palatability, early and
abundant seed production, delayed formation of fiber in stems,
holding leaves until reasonably late in the season, and the abil-
ity to recover new growth when cut or grazed, C. intermedia
was chosen as the species to be used as the crop for further in-
vestigation in the forage studies.

CULTURAL STUDIES OF CROTALARIA INTERMEDIA
PLAN OF INVESTIGATION
The cultural tests with Crotalaria intermedia were made on a
field of Norfolk sand, a portion of which had grown C. incana
previous to the tests. All of the previous crops had been remov-
ed for hay production. To determine the most profitable cul-
tural practices with C. intermedia, studies were made of rates and
methods of seeding. Yields were taken and observations made
of the quality of crotalaria grown on the plots. The forage pro-
duced in these tests was delivered to the Department of Animal
Industry of the Florida Agricultural Experiment Station for use
in hay and silage feeding trials as recorded in Part II.
RATE AND METHOD OF SEEDING
Replicated plots were planted to C. intermedia using different
rates and methods of seeding. The results are discussed below.
Drilled.-The rate of seeding on the drilled plots was varied,
first by varying the distance between the rows and keeping the
rate of seeding per row constant; second, by keeping the dis-
tance between the rows constant, and varying the amount of
seed used per row.
The seedbed was prepared by heavy disking and smoothing
with a spike-tooth harrow. The seed was planted about 1 inch
deep with a hand garden seed drill in the month of April 1934
and again in 1935. The fields were cultivated during the sum-
mer in the same manner as corn. No fertilizer was used. The
crop was harvested by hand in August of each year, when in the
bud stage. Full growth had not been reached at time of harvest,







Crotalaria for Forage


but the buds were beginning to open on the earlier maturing
plants. The results of the experiment are given in Table 2.
When the rate of seeding per row was kept constant, the
yields of crotalaria did not seem to be affected materially by the
distance between rows when this distance was less than 4 feet.
There was a decided decrease in the yield when the spacing of the
rows was as great as 4 feet with a rate of seeding of 2.6 pounds
per acre. Exceptionally dry weather prevailed during April and
May in 1935, which delayed germination and caused a high
mortality of young plants, reduced the stand very materially,
and caused the low yield recorded in Table 2. Although the yields
for 1935 were much lower than for 1934, the relative yields were
similar as affected by rates of seeding.

TABLE 2.-YIELDS OF Crotalaria intermedia PLANTED IN ROWS AT THE RATE OF 20
SEEDS PER LINEAL FOOT WHEN THE RATE OF SEEDING WAS VARIED BY VARYING
THE DISTANCE BETWEEN ROWS, 1934 AND 1935.
Distance Rate of Yields per Acre
Between Seeding Yields Green Dry Matter in of Hay Containing
Rows Iper Wt. per Acre Green Crotalaria 15% Moisture
]Acre 1934 | 1935 1934 1935 1 1934 I (tons)
(feet) (lbs.) (tons) (tons) I % I % (tons) 1 1935
2.5 4.2 5.92 2.74 24.0 35.4 1.67 0.83
3.0 3.5 5.63 2.61 24.8 25.4 1.64 .78
3.5 3.0 5.72 2.56 25.1 25.6 1.69 .77
4.0 2.6 4.17 2.18 24.3 25.7 1.19 .66


The rows grown 2.5 feet apart contained little weed and
grass growth. At this spacing stems were finer and more erect,
but a large number of lower leaves had fallen. The rows plant-
ed 3.0 feet apart produced larger, coarser stems, with fewer
fallen leaves, and there was a heavier growth of weeds and
grasses in the field. The spacing of 2.5 feet was too close for
efficient cultivation. Spacing of the rows 3.0 feet apart gave a
good stand and produced about the same yield of C. intermedia
as plantings at lower rates.
Stems were coarser when the rows were spaced 3.5 to 4.0
feet apart, and there was no increase in yield over that from
rows planted 3.0 feet apart. The wider spacing permitted a
heavier growth of grasses and weeds.
Crotalaria in the rate of seeding test when the spacing of the
rows was kept constant was harvested in the bud stage. There







Florida Agricultural Experiment Station


TABLE 3.-YIELDS OF Crotalaria intermedia PER ACRE WHEN PLANTED IN Rows
SPACED THREE FEET APART WHEN RATE OF SEEDING WAS VARIED BY VARYING THE
NUMBER OF SEEDS PER LINEAL FOOT.
Yield of Hay
Number of Containing 15% Yield of Green Seeds Sown per
Seed per Foot Moisture Forage Acre
tons tons lbs.
20 0.93 3.45 3.5
30 0.94 3.50 5.2
40 1.06 3.92 7.0
60 1.45 5.39 10.5


was very little difference in yield of the plots planted at 3.5, 5.2
and 7.0 pounds of seed per acre, as given in Table 3. There was,
however, a decidedly higher yield on those plots which had been
sown at the rate of 10.5 pounds of seed per acre.
The plots sown at the rate of 3.5 pounds per acre produced
plants with slightly coarser stems, and the leaves did not fall as
badly as on those sown more thickly. The plots sown at the rate
of 60 seeds per foot, or 10.5 pounds per acre, produced higher
yields of forage, and plants of smaller stems than plots with
lower seeding rates and allowed much less weed and grass
growth. The lower leaves, an important source of feed, had
turned yellow and dropped before time of harvest. The plots
seeded at the rate of 5.2 to 7.0 pounds per acre, while producing
slightly coarser stems, grew a product which held an abundant
leafage and therefore made a better quality feed than did those
sown at a heavier rate. The seeding of Crotalaria intermedia in
rows 3 feet apart at the rate of 5.2 to 7.0 pounds per acre may be
expected to produce the maximum yield of a high quality for-
age.
Broadcast.-A series of plots were seeded at 3 rates to
Crotalaria intermedia on April 6. The field was disked thoroughly,
the seed sown broadcast and covered with a spike-tooth harrow.
The crop was harvested on August 31. at which time the
plants were in the advanced bud stage. They were, therefore, a
few days further advanced than the crop harvested from the
drilled areas.
The plots seeded at the rate of 8 pounds per acre produced
the highest yields, as shown in Table 4. The lowest yields were
obtained from the plots seeded at the rate of 4 pounds per acre.
The seeding of 12 pounds per acre produced a slightly lower
yield than did seedings at the rate of 8 pounds; the difference







Crotalaria for Forage


is so slight, however, that it cannot be considered significant. It
is evident that the practical rate of broadcast seeding would fall
somewhere near 8 pounds per acre, and that the addition of
the 4 pounds more seed had no material effect upon the yield.

TABLE 4.-YIELDS PER ACRE OF Crotalaria intermedia ON PLOTS SOWN BROADCAST
WITH DIFFERENT RATES OF SEEDING.
Rate of Yield of Yield of Yield of Hay
Seeding Green Oven-dry Containing
per Acre Forage Forage 15% Moisture
lbs. tons tons tons
4 3.14 .89 1.05
8 5.26 1.49 1.75
12 5.03 1.43 1.68


The plots seeded with 4 pounds of seed per acre produced
larger plants with heavier and more woody stems than the heav-
ier seeded plots. The leaves held well until harvested on August
31. The stand was not dense enough to hold the weeds and grass
in check, thus there was a heavy growth of native vegetation on
the plots. This was separated from the crotalaria and is not in-
cluded in the yield weights shown in Table 4.
The plots seeded with 8 and 12 pounds of seed per acre grew
sufficient stands to crowd out the greater portion of the native
vegetation. These plots yielded much cleaner hay than did
those sown with 4 pounds of seed per acre. The plots sown with
12 pounds of seed per acre produced finer stemmed plants, but
due to intense shade, the lower leaves fell earlier than on the
plots sown more thinly.
The plots seeded at the rate of 8 pounds per acre produced
coarser stemmed plants, but the leaves adhered to the plants
longer than on the heavier seeded plots. Although the plants
were slightly larger, the higher percentage of leaves produced a
finer quality of forage.

SUMMARY AND CONCLUSIONS

Replicated plots were sown to Crotalaria intermedia using dif-
ferent rates and methods of seeding. Higher yields were obtain-
ed from the areas on which the highest rate of seeding was used
in drills. The finest quality of forage, however, was obtained
from those plots seeded in drills 3 feet apart at the rate of 5.2 to
7.0 pounds per acre.






Florida Agricultural Experiment Station


On the basis of the results obtained in these experiments
conducted on deep Norfolk sandy loam, it may be concluded that
the maximum yield of the finest quality forage is produced when
seeding at the rate of 5.2 to 7.0 pounds per acre in drills about 3
feet apart, and that it is not profitable to seed broadcast at a
rate exceeding 8 pounds of good viable scarified Crotalaria inter-
media seed per acre.

RELATIVE ADAPTABILITY OF CERTAIN CROTALARIAS
FOR HAY AND SILAGE
PLAN OF INVESTIGATION
The following seven species of Crotalaria were sown in April,
1931: C. grantiana, C. incana, C. intermedia, C. lanceolata, C. spectabilis,
C. striata, and C. usaramoensis.
The soil was a light Norfolk sand covered with native vege-
tation, which had been grazed as an open range. The seed was
broadcast and covered with a disc. No fertilizer was applied to
the field, and no cultivation was practiced after the seeds were
covered. The weeds were pulled by hand and grasses were al-
lowed to grow at will.
The crotalaria was cut with a mower. One part of each
field was harvested late in July, and another part early in Sep-
tember in 1931. The entire field was cut in one day in August
1932. As soon as mowed, the green material was hauled to a sil-
age cutter, cut into 1 to 2 inch lengths and transferred directly in-
to a one-half ton capacity rotary drum-type drier.

RESULTS OF FIELD STUDIES ON HAY
Artificially Dried Hay.-The forage was reduced in the rotary
drum drier to approximately 15 percent moisture, bagged in bur-
lap sacks and weighed. Yields were computed on the basis of the
machine-dried hay.
Since Crotalaria grantiana matures early, its growth was nearly
complete by July 31, 1931, when the first cutting was made,
therefore no increase in yield was realized by leaving the crop
until September. The highest yields from both cuttings were
obtained from the field of C. lanceolata, and the lowest yields were
made by C. grantiana, as shown in Table 5.
In 1932, Crotalaria grantiana produced an exceptionally high
yield and Crotalaria lanceolata also yielded well.



















.- -,x_ a.-.




: w., .. .... "4.-" ,"" *'" K-.. .i .i "

w. ** .. .,



*. &'o. ', *" .. ** .

Sr. < ... ,." .. .E-. -,;9.


Fig. 13.-Cutting Crotalaria intermedia for hay and silage with a sickle bar
mower.
.r ww
c1 i M




mower.


TABLE 5.-YIELDS OF MACHINE DRIED CROTALARIA HAYS WHEN
ING THE SEASON.


Species July, 1931 September
(Ibs.) (lbs.)

C. grantiana 1,055 1,014
C. incana 985 1,815
C. intermedia 1,108 1,473
C. lanceolata 1,326 2,649
C. spectabilis 1,155 2,200
C. usaramoensis 1,244 1,592

*Yields of C. intermedia for 1932 were combined from
26 and September 7, 1932, respectively.


two fields.


MOWED ONCE DUR-

August, 1932
(lbs.)
4,062

2,398*
3,316

1,885


Cut on August


Crotalaria retusa did not produce sufficient growth to be har-
vested for hay. The field of C. striata was so irregular, due to
stand, that the area was not calculated. On this account, hay
yields of this species were not computed.
Naturally Dried Hay.-If a crop is to be satisfactory for hay
in Florida, it should be curable under natural weather conditions.
Inasmuch as Crotalaria intermedia gave indications of being the
most palatable and otherwise the most promising species for feed,
a portion of the area growing C. intermedia was used for hay
studies.


, 19311






Florida Agricultural Experiment Station


An acre of Crotalaria intermedia was cut on September 21,
1933, when in bloom. Pods had formed on only a few plants.
The plants had become woody near the ground but the upper
parts were succulent. Most of the leaves were still clinging to
the plants, although a part of the lower leaves had fallen. The
stems were from 1/2 to /4 inch in diameter, when cut at a height
of about 10 inches above the ground. The plants measured 6.0
to 7.5 feet in height. The habit of growth of this species is shown
in Fig. 13.
NATURALLY DRY HAY
Drying in Shock.-As soon as the plants were cut they were
bound into small bundles, 8 to 10 inches in diameter. The bundles
were tied, using stems as bands. They were then shocked, using
6 bundles arranged as illustrated in Figure 14. Two bundles were
spread and used as caps on a portion of the shocks. The remain-
ing shocks were covered with oiled muslin to turn water.
The cutting was followed by hot, dry weather with little
breeze until October 1, when two showers fell. By Tuesday,
October 3, the hay was dry and was hauled to the barn for use
in the feeding trials. These trials are reported in Part II of this
bulletin.

Fig. 14.-Crotalaria intermedia cut, bound into bundles and shocked to cure
for hay.







Crotalaria for Forage


Drying in Swath.-A part of the Crotalaria intermedia which
was cut on September 21 was left in the swath. The plants had
dried well and were hauled to the barn on September 28. The
leaves and stems had cured well, except that the color had
bleached considerably. Part of the hay cut on September 21 was
spread on the barn floor, and stirred twice during the drying
process. After nine days the hay was not completely dried, but
this small quantity was stored in the loft with the other hay. The
branches of the plants prevented packing, and allowed sufficient
circulation of air to prevent molding. In all cases the leaves shat-
tered badly on naturally cured hay made from C. intermedia. Hay
cured in the swath shattered much more than when cured in the
shade, or in the shock. The most satisfactory hay was obtained
when the freshly cut crotalaria was bound in bundles, shocked
with not more than 6 bundles per shock, and capped as protection
against rain.
A further study was made of the two methods of drying in
1933, using crops of Crotalaria intermedia cut in (a) the prebud
stage, (b) bud stage, and (c) bloom stage.
On July 30, 1933, nine rows of Crotalaria intermedia were cut
with a mower at a height of about 6 inches from the ground.
Three rows were bound by hand into bundles about 6 inches in
diameter at the band. Stems of the crotalaria were used for
bands. The hay was set into shocks of 6 bundles each, thus allow-
ing plenty of opportunity for air circulation. The shock was then
capped with a single bundle to shed rain. The weather was dry
during this period. The hay cured fairly well except for some
mold in the center of the larger bundles and in the denser part
of the shock. As in the previous year, the leaves bleached and
shattered badly.
A second portion which was left in the swath dried thorough-
ly in 9 days, but was bleached badly. The hay which had been
cured in the shock shattered less than that cured in the swath.
On August 24 plots of crotalaria were cut in the bud stage
just previous to the opening of the first flowers. Part of the hay
was shocked and allowed to cure. Another part was cured in the
swath. This test was repeated on September 14, when the
crotalaria had reached the bloom stage.
None of the hay made from Crotalaria intermedia would be
considered high quality hay, although a fair quality was obtained
when the plants were harvested in the earlier stages. When har-






Florida Agricultural Experiment Station


vested in later stages the leaves shattered badly and there was a
large proportion of woody stems to leaves.
SUMMARY AND CONCLUSIONS
Crotalaria cured with the artificial drier, in which the plants
were cut into lengths of about 2 inches, and in which all of the
leaves were saved, produced a fair quality hay. The yield of hay
was low with most of the species tried.
When cured naturally, a coarse, stemmy, woody hay was
produced. The leaves shattered badly, especially on the later cut-
tings.
Hay made in these tests was used in the feeding trials re-
ported in Part II. Yields of hay used in these trials are given in
Tables 3, 4, and 5. The yields of Crotalaria intermedia varied be-
tween 0.93 and 1.75 tons per acre. When it is recalled that these
yields were obtained on deep Norfolk sandy soil, without fertiliz-
er, they warrant consideration of C. intermedia as a feed.
SILAGE STUDIES
Procedure.-Inasmuch as the use of crotalaria for hay did
not seem practical due to slow curing, excessive shattering of the
leaves and coarseness and large proportion of stems, it was de-
cided to investigate the crotalaria species as silage crops. In 1932
fields of Crotalaria incana, C. intermedia, C. spectabilis and C. striata
were planted and cut for silage. In 1933 C. anagyroides, C. gran-
tiana, C. goreensis, C. intermedia, C. lanceolata and C. usaramoensis were
planted and cut for the same purpose. These fields were located
on deep Norfolk sand. The seed was drilled in rows 3 feet apart in
the middle of April. The crops were cultivated 3 times during
the season. The forage was sampled by selecting plants in the
field at time of harvest. These were cut into 1 to 2 inch lengths
and sealed in glass jars for dry matter determinations. The green
crotalaria was used in silage studies, which are reported in Part
II of this bulletin.
Results.-The dates of cutting and yields are recorded in
Table 6. The yields were much higher in 1932 than in 1933.
Crotalaria incana yielded over 81/2 tons of green material per acre,
while C. spectabilis yielded nearly twice as much. The field of
C. striata was so irregular, due to stand, and the stand so thin that
it was not possible to obtain satisfactory yield records. It was
omitted from the table.








Crotalaria for Forage 31

TABLE 6.-YIELDS PER ACRE OF EIGHT SPECIES OF CROTALARIA OF SINGLE HARVESTS
IN 1932 AND 1933 FOR INVESTIGATION AS SILAGE.
Time of Harvest
Species 9/22/32 7/25/33 9/27/33
(lbs.) (Ibs.) (lbs.)
C. anagyroides ....... ... ................ 9,813(b)
C. grantiana ............. 5,936(a)
C. goreensis .............. ... ......... 12,896(a)
C incana 17,390(c) ....... ...............
C. intermedia 22,630(c)...........
C. lanceolata ................ 8,052(b) 10,160(c)
C. spectabilis 34,400(c) ....
C. usaramoensis ...... ....... 4,288 (a)
(a) prebud, (b) bloom, or (c) pod stage of development when harvested. The
yield of C. intermedia harvested on Sept. 27, 1933, was not calculated because of
irregularity of stand in the field.

In 1933 the highest yield was obtained from C. goreensis,
which requires a long growing season, and seeds late in the fall
and early winter. Only in exceptionally long seasons is seed
produced and matured before frost. For this reason C. goreensis
is not a practical crop in the locality of Gainesville.
The field of C. intermedia in 1933 was so irregular in stand
that accurate measurements were impossible, and therefore the
yields were not calculated. As nearly as could be estimated the
yields were approximately one-half of those of 1932, and about
equal to those of C. lanceolata, cut on the same date.
In 1934 C. intermedia was seeded in drilled rows 3 feet apart,
cultivated as in 1932 and 1933, and harvested at periods represent-
ing 4 stages of development: namely, the prebud, bud, bloom,
and pod stages.
"Prebud" represents a stage of development just before the
first flower buds appeared. The plants were in a state of vege-
tative growth at this period. The leaves had not fallen and the
stems, with the exception of the lower portions, were succulent
and tender. The plants were still growing rapidly, and thus the

TABLE 7.-YIELDS OF Crotalaria intermedia HARVESTED AT DIFFERENT STAGES OF
DEVELOPMENT TOR USE AS SILAGE IN 1934.
Dry Matter
Stage of Date Green Weight Dry Yields per
Development Harvested per Acre Matter Acre
(lbs.) % (lbs.)
Prebud July 29 2782 18.6 517
Bud August 24 7630 21.6 1,648
Bloom September 14 8271 24.8 2,051
Pod October 6 R0'O 2R.6 2.347







Florida Agricultural Experiment Station


yield was low as compared with yields in the bud stage, cut near-
ly a month later. The plants contained a high percentage of
moisture as is indicated by the lower dry weight percentage in
Table 7.
The cutting at the "bud" stage of development was made af-
ter the buds had formed on the plants and an occasional spike
was in bloom. The crop made considerable growth between the
cutting in the prebud stage and that in the bud stage. There had
been an increase of dry matter in the plant and the yield of green
material had increased more than two and one-half times. The
most marked growth of the season had occurred during the last
half of July and the month of August. The plants still held their
leaves well even in a heavy stand. A maximum of succulent
material was obtained at this stage.
The bloom stage was the time when the plants were in full
bloom with a few pods on some plants. The harvest, represent-
ing this stage of development, produced a substantial increase in
yield. There was a higher dry matter content, which indicated
a decrease in succulence of plant material.
The pod stage represented that stage of development when
the majority of the pods were set, and the plants were beginning
to mature. A few spikes of ripened seedpods were showing on
the early plants. Many of the lower leaves had fallen and the
lower stems had become woody. There was a decrease in yield
at this stage of development, which can be accounted for by the
loss of leaves. The percentage of dry matter had increased ma-
terially between September 14 and October 6, and in general
a product was harvested which was high in fiber and had rela-
tively few leaves.
SUMMARY AND CONCLUSIONS
Nine species of crotalaria were planted and harvested for
silage studies in 1932 and 1933. The highest yields in 1932 were
made by C. spectabilis when harvested on September 23, and by
C. goreensis in 1933 when harvested September 27.
In 1934 Crotalaria intermedia was harvested in 4 stages of de-
velopment; prebud, bud, bloom, and pod. Yields were calculat-
ed and the dry matter content determined.
The crop in the prebud stage was in an actively growing con-
dition, very succulent, and high in leafage, but produced a low
yield of dry matter. In the bud stage the yield of succulent for-







Crotalaria for Forage


age was nearly tripled. It still had a high content of leaves. By
the time the plants came into bloom the lower leaves had begun
to drop, and the stems became coarse and woody. There was a
substantial increase in yield. Most of the lower leaves had fallen
by the time the pod stage had been reached. The yield was ap-
proximately the same as when harvested in the bloom stage.
C. intermedia harvested in the bud stage produced a maximum
yield of the quality of forage desired for silage.


Part II. Value of Crotalaria as Feed
R. B. BECKER, 1W. M2. NEAL AND P. T. DIx ARNOLD

INTRODUCTION
Legume forages usually are considered as a desirable part of
rations for cattle. The search for new legume forage crops that
could be grown on sandy soils prompted a cooperative investi-
gation of the possible feeding values, as pasturage, hay and sil-
age, of several selected crotalarias which had shown their adapt-
ability in the forage crops nursery at Gainesville.

REVIEW OF LITERATURE
Scott (27) conducted a single feeding trial with six Jersey
cows in which alfalfa meal and ground Crotalaria striata hay (nat-
urally cured) were added to the mixed concentrates. From the
limited data obtained, it appeared that this crotalaria might pos-
sess some merit as a feed for cattle. In the East Indies, van Hal-
ten (17) reported that Crotalaria usaramoensis was eaten by cattle
and horses.
McKee and Enlow (19) have described the characteristics,
culture and adaptability of many species of the genus Crotalaria,
and suggested that this group of plants might contain some species
suitable for forage.
PLAN OF INVESTIGATION
Several species of crotalaria were selected by the agrono-
mists, from sub-tropical and tropical species based on forage
yields and growth characteristics. It was hoped that one or
more of these might prove of value as a forage on the sandy
soils of the coastal plains region.
Tests were made with cattle as to the relative palatability
of the selected species when offered as green forage in the field,







Crotalaria for Forage


age was nearly tripled. It still had a high content of leaves. By
the time the plants came into bloom the lower leaves had begun
to drop, and the stems became coarse and woody. There was a
substantial increase in yield. Most of the lower leaves had fallen
by the time the pod stage had been reached. The yield was ap-
proximately the same as when harvested in the bloom stage.
C. intermedia harvested in the bud stage produced a maximum
yield of the quality of forage desired for silage.


Part II. Value of Crotalaria as Feed
R. B. BECKER, 1W. M2. NEAL AND P. T. DIx ARNOLD

INTRODUCTION
Legume forages usually are considered as a desirable part of
rations for cattle. The search for new legume forage crops that
could be grown on sandy soils prompted a cooperative investi-
gation of the possible feeding values, as pasturage, hay and sil-
age, of several selected crotalarias which had shown their adapt-
ability in the forage crops nursery at Gainesville.

REVIEW OF LITERATURE
Scott (27) conducted a single feeding trial with six Jersey
cows in which alfalfa meal and ground Crotalaria striata hay (nat-
urally cured) were added to the mixed concentrates. From the
limited data obtained, it appeared that this crotalaria might pos-
sess some merit as a feed for cattle. In the East Indies, van Hal-
ten (17) reported that Crotalaria usaramoensis was eaten by cattle
and horses.
McKee and Enlow (19) have described the characteristics,
culture and adaptability of many species of the genus Crotalaria,
and suggested that this group of plants might contain some species
suitable for forage.
PLAN OF INVESTIGATION
Several species of crotalaria were selected by the agrono-
mists, from sub-tropical and tropical species based on forage
yields and growth characteristics. It was hoped that one or
more of these might prove of value as a forage on the sandy
soils of the coastal plains region.
Tests were made with cattle as to the relative palatability
of the selected species when offered as green forage in the field,







Crotalaria for Forage


age was nearly tripled. It still had a high content of leaves. By
the time the plants came into bloom the lower leaves had begun
to drop, and the stems became coarse and woody. There was a
substantial increase in yield. Most of the lower leaves had fallen
by the time the pod stage had been reached. The yield was ap-
proximately the same as when harvested in the bloom stage.
C. intermedia harvested in the bud stage produced a maximum
yield of the quality of forage desired for silage.


Part II. Value of Crotalaria as Feed
R. B. BECKER, 1W. M2. NEAL AND P. T. DIx ARNOLD

INTRODUCTION
Legume forages usually are considered as a desirable part of
rations for cattle. The search for new legume forage crops that
could be grown on sandy soils prompted a cooperative investi-
gation of the possible feeding values, as pasturage, hay and sil-
age, of several selected crotalarias which had shown their adapt-
ability in the forage crops nursery at Gainesville.

REVIEW OF LITERATURE
Scott (27) conducted a single feeding trial with six Jersey
cows in which alfalfa meal and ground Crotalaria striata hay (nat-
urally cured) were added to the mixed concentrates. From the
limited data obtained, it appeared that this crotalaria might pos-
sess some merit as a feed for cattle. In the East Indies, van Hal-
ten (17) reported that Crotalaria usaramoensis was eaten by cattle
and horses.
McKee and Enlow (19) have described the characteristics,
culture and adaptability of many species of the genus Crotalaria,
and suggested that this group of plants might contain some species
suitable for forage.
PLAN OF INVESTIGATION
Several species of crotalaria were selected by the agrono-
mists, from sub-tropical and tropical species based on forage
yields and growth characteristics. It was hoped that one or
more of these might prove of value as a forage on the sandy
soils of the coastal plains region.
Tests were made with cattle as to the relative palatability
of the selected species when offered as green forage in the field,







Crotalaria for Forage


age was nearly tripled. It still had a high content of leaves. By
the time the plants came into bloom the lower leaves had begun
to drop, and the stems became coarse and woody. There was a
substantial increase in yield. Most of the lower leaves had fallen
by the time the pod stage had been reached. The yield was ap-
proximately the same as when harvested in the bloom stage.
C. intermedia harvested in the bud stage produced a maximum
yield of the quality of forage desired for silage.


Part II. Value of Crotalaria as Feed
R. B. BECKER, 1W. M2. NEAL AND P. T. DIx ARNOLD

INTRODUCTION
Legume forages usually are considered as a desirable part of
rations for cattle. The search for new legume forage crops that
could be grown on sandy soils prompted a cooperative investi-
gation of the possible feeding values, as pasturage, hay and sil-
age, of several selected crotalarias which had shown their adapt-
ability in the forage crops nursery at Gainesville.

REVIEW OF LITERATURE
Scott (27) conducted a single feeding trial with six Jersey
cows in which alfalfa meal and ground Crotalaria striata hay (nat-
urally cured) were added to the mixed concentrates. From the
limited data obtained, it appeared that this crotalaria might pos-
sess some merit as a feed for cattle. In the East Indies, van Hal-
ten (17) reported that Crotalaria usaramoensis was eaten by cattle
and horses.
McKee and Enlow (19) have described the characteristics,
culture and adaptability of many species of the genus Crotalaria,
and suggested that this group of plants might contain some species
suitable for forage.
PLAN OF INVESTIGATION
Several species of crotalaria were selected by the agrono-
mists, from sub-tropical and tropical species based on forage
yields and growth characteristics. It was hoped that one or
more of these might prove of value as a forage on the sandy
soils of the coastal plains region.
Tests were made with cattle as to the relative palatability
of the selected species when offered as green forage in the field,







Crotalaria for Forage


crotalic acid gave monocrotic acid. Monocrotaline resembles the
alkaloids of 17 species of the genus Senecio, Heliotropium lasiocar-
pum, Trichodesma incanum, and a species of Erechtites.
The crystalline form of monocrotaline is shown by micro-
photographs of the substance recrystallized from chloroform,
and from absolute alcohol, in Figure 17.
Neal, Rusoff, and Ahmann (22) found that the administra-
tion of this alkaloid caused lowering of blood pressure in dogs
and decreased the rate and amplitude of beat of a terrapin heart
in situ, even when the vagus nerve was severed.
Similar symptoms and lesions were observed in experiment-
al animals to which either the monocrotaline alkaloid or whole
C. spectabilis seeds were administered. This is evidence that this
alkaloid was the toxic principle of the seeds. The 24-hour lethal
dose for chickens was found to be 65 milligrams of monocrota-
line per kilogram of live weight.
Two separate alkaloids were extracted from the seeds of
C. retusa by Rusoff (24), which differed in melting point. One
was fat soluble and the other was water soluble. The toxicity of
these separate extracts was not determined. Greshoff (16), in
Java, reported the presence of a highly toxic alkaloid from
C. retusa seeds as early as 1890.

Part III. General Discussion, Summary and
Conclusions

DISCUSSION OF PRODUCTION AND FEEDING
OF CROTALARIA
The investigation of the crotalarias as forage involved the
study of certain species of the genus which showed character-
istics that would adapt them for such use. Eleven species were
selected, including the widely grown C. spectabilis and C. striata.
Nine species were planted in plots and used in grazing trials
and two others were added later, from which one, C. intermedia.
was selected on the basis of palatability, growth characters, and
general seeding habits for more extensive studies.
The culture of C. intermedia was studied in relation to the
yield and quality of hay and silage produced. This species gave
reasonably good yields on a light sandy soil, yet perhaps not
sufficiently good to recommend it over the present commercial
legume crops, such as cowpeas.







Crotalaria for Forage


crotalic acid gave monocrotic acid. Monocrotaline resembles the
alkaloids of 17 species of the genus Senecio, Heliotropium lasiocar-
pum, Trichodesma incanum, and a species of Erechtites.
The crystalline form of monocrotaline is shown by micro-
photographs of the substance recrystallized from chloroform,
and from absolute alcohol, in Figure 17.
Neal, Rusoff, and Ahmann (22) found that the administra-
tion of this alkaloid caused lowering of blood pressure in dogs
and decreased the rate and amplitude of beat of a terrapin heart
in situ, even when the vagus nerve was severed.
Similar symptoms and lesions were observed in experiment-
al animals to which either the monocrotaline alkaloid or whole
C. spectabilis seeds were administered. This is evidence that this
alkaloid was the toxic principle of the seeds. The 24-hour lethal
dose for chickens was found to be 65 milligrams of monocrota-
line per kilogram of live weight.
Two separate alkaloids were extracted from the seeds of
C. retusa by Rusoff (24), which differed in melting point. One
was fat soluble and the other was water soluble. The toxicity of
these separate extracts was not determined. Greshoff (16), in
Java, reported the presence of a highly toxic alkaloid from
C. retusa seeds as early as 1890.

Part III. General Discussion, Summary and
Conclusions

DISCUSSION OF PRODUCTION AND FEEDING
OF CROTALARIA
The investigation of the crotalarias as forage involved the
study of certain species of the genus which showed character-
istics that would adapt them for such use. Eleven species were
selected, including the widely grown C. spectabilis and C. striata.
Nine species were planted in plots and used in grazing trials
and two others were added later, from which one, C. intermedia.
was selected on the basis of palatability, growth characters, and
general seeding habits for more extensive studies.
The culture of C. intermedia was studied in relation to the
yield and quality of hay and silage produced. This species gave
reasonably good yields on a light sandy soil, yet perhaps not
sufficiently good to recommend it over the present commercial
legume crops, such as cowpeas.






Florida Agricultural Experiment Station


C. intermedia stood grazing to some extent. The crop was not
as palatable to cattle as were the common grasses found in cul-
tivated fields. It was found that crude fiber increased quite rapid-
ly after the buds were formed. After the first pods appeared the
fiber content became too high for the plant to be used as forage.
The hay of this species harvested when in bloom contained more
fiber than the legume hays commonly used, as shown in Table
28. When cut early, and high above the lower axial buds, it
made palatable hay for cattle and mules, and still produced a
limited second crop.
TABLE 28.-COMPARISON OF THE CHEMICAL COMPOSITION OF C. intermedia WITH
OTHER COMMON LEGUME HAYS.




Sa r). U a VD


C. intermedia 21 90.0* 13.2 1.9 36.0 34.2 4.2 .62 .29 .21
Alfalfa hay 632 90.4 14.7 2.0 29.0 36.4 8.3 1.43 .... .21
Cowpea hay 41 90.4 18.6 2.6 23.3 34.6 11.3 1.13 .... .25
Soybean hay 77 90.8 14.8 3.3 28.4 37.0 7.3 .96 .. .25
*These analyses are of freshly cut C. intermedia, mostly in the bud stage, com-
puted to the same dry matter basis as the legume hays.
Hay was made by drying the crop artificially, and by nat-
ural curing, for use in the palatability, maintenance, and earlier
digestion trials. Since frequent summer rains interfered with
natural curing of hay in the early stages of growth, and arti-
ficial drying was expensive, it appeared more practical under
Florida conditions to study these species of crotalaria as silage.
With only limited quantities of green forage of each species
available, a laboratory silo (20) was designed which was com-
parable with a regular commercial silo in its effectiveness. Four
of these concrete oit silos were built of a size to contain 1.0 to 1.5
tons of cut green forage. Due to the method of filling and sealing
these laboratory silos, the silage in them compared in quality
and density with that six feet below the surface in standard up-
right silos.
The dry matter of C. intermedia harvested in the bud stage
of development was found to be slightly less valuable as feed
for dairy cows than the dry matter of No. 1 green alfalfa hay.
Cows refused a larger proportion of the crotalaria silage than of
corn silage or alfalfa hay fed during the experiments.







Florida Agricultural Experiment Station


as artificially dried hay, and as silage. One single species was
selected for further investigation, based on relative palatability,
growth habits of the plants, relative yields, seed production, re-
sponses to grazing by cattle, and relative freedom from attack
by insects and diseases.
Cattle were used in brief maintenance trials when grazing
C. intermedia, and when eating it as hay. Digestion trials were
conducted with four cows on quite mature C. intermedia hay and
with four steers on the silage.
Records were obtained of the consumption of naturally cured
C. intermedia hay by mules.
C. intermedia silage was compared with No. 1 green federal
grade alfalfa hay for milk production when fed to Jersey cows in
standard double-reversal feeding trials (15). Flavor and odor
of the milk were observed while the cows had access to this
silage. In conjunction with the palatability and feeding trials,
detailed studies were made of the ensilability of crotalarias and
of the capacity of upright silos for this crop.
Two species, C. spectabilis and C. retusa, were found to be toxic
in the course of the investigation. The other species used were
free from toxic effects upon animals.

EXPERIMENTAL RESULTS
I. PALATABILITY TRIALS
Palatability of Crotalaria as Green Forage.-Nine species of
crotalaria were drilled in plots (see Part I). These species in-
cluded Crotalaria grantiana, C. incana, C. intermedia, C. lanceolata, C.
maxillaris, C. retusa, C. spectabilis, C. striata, and C. usaramoensis.
When most of the taller species were from 10 to 20 inches high,
two dry Jersey cows were placed in the field for 15 days. Water
was available in the field. At the end of this period these ani-
mals were withdrawn and the crop given about a one-week rest,
after which two other cows were placed in the field for 24 days.
Following a subsequent 25-day rest, one each of the above groups
of cows was returned to the field for a 15-day period. During
these grazing periods observations were made daily to observe
the plant responses, and to estimate the number of lineal feet of
row on which the cows had grazed. Generally, the cows grazed
on the scattered grass or weeds for 1 to 4 days before beginning
to eat crotalaria.






Crotalaria for Forage


During the first trial the cows preferred C. incana and C.
intermedia to the other species. C. maxillaris, C. grantiana and C. incana
were eaten in appreciable amounts in the second period. In the
third trial the cows ate C. incana, C. intermedia and C. maxillaris.
These two cows also ate the leaves of C. spectabilis between Sep-
tember 24 and 28, when the plant was in full bloom. C. striata,
C. lanceolata, C. retusa and C. usaramoensis were not eaten by the
cows during the summer of 1931.
Two pigs receiving supplementary concentrates were fenced
off in one end of the field for 14 days. These pigs ate none of the
crotalarias.
Palatability of the green forage was observed again during
the summer of 1932. The plot was planted as before, with the
exception that C. retusa was replaced by C. anagyroides. Two cows
were used in each of four grazing periods of 14 to 18 days, with
appropriate intermediate periods for the plants to grow.
In the first trial all foliage was eaten from the C. incana
plants, C. intermedia was grazed considerably, followed in turn by
C. usaramoensis, C. lanceolata, and C. anagyroides.
One end of all rows was mowed about 18 inches from the
ground, and the plants were allowed 26 days to grow. The two
cows on the second grazing preferred grass and weeds, although
they did graze five lineal feet of row of C. incana and one foot of
C. anagyroides._ Since the cows ate so little crotalaria, the data
from this grazing period were disregarded when selecting one
species for further investigation.
Cows in the third trial grazed all leaves from C. incana, then
turned to C. intermedia. After grazing that species closely they
ate large amounts of C. anagyroides as well as a few plants of
C. maxillaris. Two cows on the fourth grazing palatability trial in
1932 showed little preference between C. incana and C. intermedia,
following these in order with C. lanceolata, C. anagyroides and
C. usaramoensis. Generally, the cows preferred the more tender
forage from the ends of the rows mowed during the season, to
that of the more mature plants.
Palatability of Crotalaria as Hay.-The several species of cro-
talaria were mowed, cut into short lengths, and dried in a labora-.
tory-sized commercial drier by a high-temperature, parallel cur-
rent, direct air blast from an oil burner. The hay was stored
loosely in bags.






Florida Agricultural Experiment Station


Fig. 15.-Relative palatability of the different species of crotalaria was de-
termined by the order of preference shown by cows when given free access to
them. Wire racks divided into four compartments each were used.

Four-compartment racks of woven wire were constructed
above solid feed troughs, as shown in Figure 15. The artificially
dried hays were placed in the racks, one species per compart-
ment, as listed in Table 8.

TABLE 8.-RELATIVE PALATABILITY OF ARTIFICIALLY-DRIED HAY MADE FROM SOY-
BEANS AND SEVEN SPECIES OF CROTALARIA, AS DETERMINED BY LOTS OF THREE TO
EIGHT HEAD OF CATTLE, IN 1931 1932.
Rank, based on order of preference and relative amounts of hay eaten
Trial C. inter- C. C. lanceo- C. usaramo- C. gran- C. specta- C. _
Number Soybean media incana lata ensis .... tiana bills striata
1 1 6 4 5 2 3 7 7
2 1 3 2 4 5 6 7 7
3 4 2* 1 2* 5 6 7 7
4 1 2 4 5 3 6 7 7
5 2 1 4 3 5* 5* 7 7
Average 1 2 3 4 5 6 7* 7*
*No distinguishable difference in rank.
A total of 15 cattle in groups of 3 to 8 animals was used in
five consecutive palatability trials of 7 species of crotalaria
as artificially dried hay during the winter of 1931. Dried soy-
bean hay was offered in the eighth compartment.
The cattle preferred soybean hay to all other in the racks.
C. intermedia, C. incana, and C. lanceolata ranked in palatability in the
order given. C. usaramoensis and C. grantiana were fifth and sixth.


II







Crotalaria for Forage 37

C. striata and C. spectabilis ranked last, with no appreciable amounts
of either species consumed.
Three additional trials in which dried Napier grass, dried
sugarcane, and Natal grass hay were made accessible did not
change the order of preference shown by the cows for C. inter-
media, C. lanceolata, and C. usaramoensis. The relative location of
the various species in the racks was changed from trial to trial.
Larger amounts of hay were available from the 1932 crop
for the next series of palatability trials. During that winter three
dry Jersey cows were used as experimental animals in the early
trials and three grade Hereford yearlings later. C. anagyroides
was used in place of soybean hay in this series. In the fourth of
the 12 trials No. 1 green federal grade alfalfa hay replaced
C. spectabilis. During this particular trial the animals ate all of
the alfalfa before touching any of the crotalaria.
C. usaramoensis and C. intermedia ranked as first and second
choice, respectively, in the 1932 series, followed in order by
C. incana and C. lanceolata hay. The Jersey cows ate none of the
C. spectabilis,* whereas the Hereford yearlings consumed suffi-
cient of it to place this species ahead of C. striata in last place.
Results of these trials and the average rating of all preferences
are shown in Table 9.

TABLE 9.-RELATIVE PALATABILITY OF ARTIFICIALLY-DRIED HAY MADE FROM EIGHT
SPECIES OF CROTALARIA AS DETERMINED BY TWO LOTS OF THREE HEAD OF CATTLE
EACH, IN 1932 1933.
Rank based on order of preference and relative amounts of hay eaten
Trial C. usara- C. inter- C. C. lan- C. gran- C. spec- C. anagy- C.
Number moensis media incana ceolata tiana tabilis roides striata
Preference of Lot 1
1 2 3 1 5 6 8 4 7
2 2 3 1 4 6 8 5 7
3 1 3 2 4 5 8 6 7
4 3 4 2 5 7 none* 8 6
5 3 2 1 5 6 8 7 4
Preferene of Lot 2**
6 2 1 3 5 4 7 6 8
7 2 1 3 6 4 5 7 8
8 2 1 3 5 4 6 8 7
9 2 1 3 4 6 5 8 7
10 1 2 3 4 7 5 8 6
11 2 1 4 5 6 3 7 8
12 1 2 4 5 8 3 6 7
Rank 1 2 3 4 5 6 7 8
*In this particular trial, alfalfa hay replaced C. spectabilis, and all of it was
eaten in preference to any crotalaria.
**The three grade Hereford yearlings making up Lot 2 died of C. spectabilis
poisoning in 11, 22, and 24 days respectively, after the close of the 12th trial.

*This is discussed in detail in the section on "Toxicity."






Florida Agricultural Experiment Station


Relative Palatability of Crotalaria Silages.-Four small con-
crete pit silos 43 inches in diameter and between 74 and 81 inches
in depth were constructed in 1932 (20). These silos were filled
with C. incana, C. intermedia, C. spectabilis and C. striata, respectively.
The forage was packed firmly by tramping and tamping, cover-
ed with a layer of soil, and allowed to ensile from September 23
to December 12. Each of these species ensiled satisfactorily, the
silages varying in aroma and appearance with the species.
The relative palatability of the several silages was determin-
ed by placing these in feed troughs to which cattle had free ac-
cess, and recording the preference shown by the animals, based on
observation. The general preference of 13 Jerseys and 24 native
cattle was for C. intermedia silage. The silage made from C.
spectabilis*, though dark in color, and possessing a characteristic
pungent odor, was given slight preference over C. incana silage
by the cattle. Droppings of the cattle that ate C. spectabilis silage*
were quite dark in color. C. striata silage was rejected by all ani-
mals, although it had a green color and not unpleasant odor. A
small amount of C. intermedia silage was offered to 32 dairy cows,
only two of which rejected it entirely. Two others refused a part
of the amount offered.
The four small silos were filled again on July 25, 1933, with
C. grantiana, C. lanceolata, C. usaramoensis, and with Whatley's Pro-
lific field corn. They were opened on September 8. Twenty-
four grade Hereford and native beef cattle, 17 Jersey cows, and 6
Jersey heifers showed their preference for corn silage. None of
the beef animals had eaten corn silage prior to this test.
C. lanceolata, C. usaramoensis, and C. grantiana silages were consum-
ed in order named.
These silos were refilled on September 27, 1933, with C.
intermedia and C. lanceolata, which ranked high in the two pre-
ceding trials, in addition to C. anagyroides and C. goreensis, the
seed of which had not been available in quantity prior to 1933.
The silos were opened on November 15 and feeding continued
through November 25. The cattle under observation on this
silage included 24 native and grade Hereford cows, 19 Jersey
cows and 8 Jersey heifers. A very decided preference was shown
for C. intermedia silage, followed in turn by C. lanceolata, C. anagy-
roides and C. goreensis

*The toxicity of C. spectabilis silage has not been tested. See page 58 concerning
toxicity of this species.







Crotalaria for Forage


Stage of Development of C. intermedia as It Affects Palatability
of Silage.-During the summer of 1934 C. intermedia was harvest-
ed at four stages of development, namely the pre-bud, bud,
bloom, and pod stages, and ensiled in the small concrete silos.
Differences in dates of cutting allowed a longer ensiling time for
that forage harvested early. These ensiling periods were 128,
103, 82, and 63 days in length, respectively, when the silos were
opened to begin feeding on December 5, 1934. The same methods
used with the hay were followed in feeding the silage to 15 Jer-
sey cows and 32 grade Hereford and native beef cattle. The
striking decrease in palatability of the more mature silage is seen
by the proportion which was refused, as shown in Table 10.

TABLE 10.-RELATION OF STAGE OF DEVELOPMENT OF C. intermedia TO THE ACIDITY Or
SILAGE, AND THE AMOUNT EATEN BY CATTLE.
Development Acidity of
at Ensiling the Pressed Silage Silage Silage
Harvest Period Juice Offered Refused Eaten
days pH pounds pounds percent
Pre-bud 128 5.08 972 8 99.2
Bud 103 5.12 1,008 285 71.7
Bloom 82 4.75 1,056 351 66.8
Pod 63 5.48 719 448 37.7

It appeared from chemical composition of the C. intermedia
silage, as shown in Table 21, that as the crude fiber in the dry
matter increased from 32 to 53 percent the protein decreased
from 17 to less than 11 percent and the ether extract from 3.55
to 1.79 percent. Changes in the acidity varied independently of
palatability. This marked change in composition of the C.
intermedia with two months longer growth affected its value as a
forage crop for livestock.
C. intermedia, while in the pre-bud stage, had a fiber content
in the dry matter within the range of common hay crops, which
is ordinarily between 27 and 33 percent.

II. NUTRIENT VALUE OF CROTALARIA INTERMEDIA
Digestion Trials with Mature Crotalaria intermedia Hay.-Facil-
ities were made available in the autumn of 1932 to determine the
digestibility of C. intermedia hay. Forage of C. intermedia was
harvested when a few pods were on the plants and the earliest
seeds approached maturity. One lot of forage was dried artifi-







Florida Agricultural Experiment Station


cially and a second lot was cured naturally in small shocks. The
naturally cured hay was cut into three-fourths inch lengths prior
to feeding, so as to have both hays of equal fineness for the di-
gestion trials.
Two dairy cows in the digestion trials were fed with the arti-
ficially dried C. intermedia hay, while two others received that
cured naturally. The first trial was of 25 days' duration (15-
days preliminary and 10-days experimental). The kinds of hay
were reversed and the cows were used in another trial which
consisted of a 10-day preliminary and a 10-day experimental per-
iod. They failed to eat sufficient C. intermedia hay harvested at
this stage of development to maintain their body weights. Sub-
sequent analyses of these two hays showed that the crude fiber
contents were higher than is desirable for feeding purposes. Be-
cause of inconsistent and irregular feed intakes, two cows' rec-
ords on each hay were discarded.
The composition of the forage and coefficients of digestibility
obtained under these conditions are given in Tables 11 and 12. It
is well to consider again that the feed intakes of these four cows
were too low, and that consequently the metabolic waste and ir-
regularity of feed intake and excretion rendered these coefficients
of digestibility unreliable. The significant point is that C.
intermedia, harvested at a stage of development when its fiber
content is excessive, is not desirable for use as feed for livestock.

TABLE 11.-COMPOSITION OF Crotalaria intermedia HAY AND SILAGE USED IN DIGES-
TION TRIALS AS COMPARED WITH OTHER STANDARD FEEDS.
Crude Crude Nitrogen-free Ether
Roughages Moisture Protein Fiber Extract Extract Ash
percent percent percent percent percent percent
C. intermedia hay
artificially dried 8.3 10.0 38.8 37.8 2.1 3.0
C. intermedia hay
naturally dried 6.6 10.1 45.0 34.4 1.2 2.7
C. intermedia silage 72.9 3.3 12.5 8.3 .8 2.2
Alfalfa hay, average
of all analyses* 8.6 14.7 29.0 36.4 2.0 8.3
Corn fodder, medium
moisture* 17.5 6.7 21.7 46.9 2.1 5.1
Oat straw* 10.4 4.0 36.1 41.2 2.3 6.0
*Taken from "Feeds and Feeding," 20th edition, by F. B. Morrison.







Crotalaria for Forage


TABLE 12.-COEFFICIENTS OF DIGESTIBILITY AND DIGESTIBLE NUTRIENTS OF C. Inter-
media HAY AND SILAGE.
Coefficients of Digestibility Average
Average Total
Dry Crude Ether Crude Nitrogen-free Digestible Digestible
Animal Matter Protein Extract Fiber Extract Crude Protein Nutrients
percent percent percent percent percent percent percent

C. intermedia hay, dried naturally*

151 30.6 37.5 32.8 24.9 41.6

296 60.4 57.5 52.2 64.2 67.6 4.8 44.8

C. intermedia hay, dried artificially*

151 40.6 42.4 73.2 32.6 49.5

228 44.4 42.7 51.7 45.9 57.5 4.3 42.7
Average 45.5 55.0 41.9 54.0 4.6 43.8

C. intermedia silage

E-49 62.02 65.25 26.20 36.10

E-50 63.93 73.26 32.82 41.87
E-51 65.79 61.69 40.09 45.16
E-52 59.75 67.49 31.74 39.15
Average 62.87 66.92 32.71 40.57 2.1 10.7
*These coefficients are deemed unsatisfactory, due to irregular and insufficient
feed intakes, as discussed on page 40.

Digestion Trials with Crotalaria intermedia Silage.-In con-
trast with the less successful digestion trials with cows on the
mature C. intermedia hay, a satisfactory digestion trial was con-
ducted in 1935 with four steers receiving C. intermedia silage to-
gether with a basal supplement of cut alfalfa hay and cotton-
seed meal (41 percent total crude protein). The average coeffi-
cients of digestibility of this silage were: crude protein, 62.87
percent; ether extract, 66.92 percent; crude fiber, 32.71 percent;
and nitrogen-free extract, 40.57 percent. These coefficients were
higher for protein and ether extract and lower for fiber and
nitrogen-free extract than those obtained in the less satisfac-
tory trial with the mature hay.
Details of the digestion trial with C. intermedia silage were
presented in Florida Station Bulletin 279 (21), and are summar-
ized in Table 12.







Florida Agricultural Experiment Station


III. PRACTICAL OBSERVATIONS WITH COWS AND
MULES
Grazing Trials with Native Cows.-A fenced area of about
two acres was planted to C. intermedia in the spring of 1933. The
plants had attained a height of about 30 inches and were in the
full bloom to early pod stages of development by September
23 when native cattle were placed in the field. No supplemen-
tary feed was allowed. The cattle grazed grass along the
fence for a few days, before becoming accustomed to the cro-
talaria. They ate the leaves and tender tops of the crotalaria
during the remainder of a 30-day period. One cow dropped a
calf during the period. The cattle practically maintained their
weight during this brief grazing trial, as seen in Table 13.

TABLE 13.-VARIATIONS IN THE WEIGHTS OF NATIVE CATTLE WHILE ON C. intermedia
PASTURE.

Cow Calf of Cow Yearling
Weight Day No. 15 Cow No. 15 No. 21 Steer
pounds pounds pounds pounds
Sept. 25 645 ...... 380 450
Sept. 30 715 ... 375 450
Oct. 21 725 .... 410 445
Oct. 24 610 65 400 430

Maintenance Trials with Dairy Cows.-Three mature dairy
cows were fed artificially dried C. intermedia hay for two months,
and an additional cow was fed it for one month. This hay was
made while the crotalaria was in full-bloom to early-pod stages
of development, and contained a small proportion of leaves to
stems. The maintenance trial was followed immediately by
trials of the digestibility of artificially dried and naturally cured
C. intermedia hay. In the latter trials the cows were fed for 42
days, including the preliminary periods. They failed to main-
tain body weight on the mature forage during the entire course
of these trials, as shown in Table 14.

TABLE 14.-BoDY WEIGHTS OF COWS WHILE BEING FED SOLELY ON C. intermedia
HAY HARVESTED IN THE FULL-BLOOM TO EARLY-POD STAGES OF DEVELOPMENT.
Dates Cow No. 151 Cow No. 288 Cow No. 296 Cow No. 352
pounds pounds pounds pounds
Nov. 16 18 1,093 968 1,100
Dec. 16 18 1,056 913 1,047 804
Jan. 15 17 1,048 887 1,051 726
March 2* 910 703 834 605
*The 42-day digestion trials closed on March 2, 1933.







Crotalaria for Forage


Chemical analyses of the C. intermedia hay used in these
maintenance and digestibility trials showed it to be excessive-
ly high in crude fiber, and hence lacking in productive feed
value (see Table 11). Later work indicated that C. intermedia
should be harvested before the bloom stage if it is to be used
as feed.
Cow No. 151 was pregnant and dropped a 50-pound bull
calf on March 24, 1933. Undoubtedly pregnancy affected her
body weights during this trial. The other cows were open and
dry.
Crotalaria intermedia Hay for Mules.-During 1933 C. intermedia
was cut, bundled, and cured naturally in shocks in the field,
and later stored under shelter until used in palatability trials
with mules. The forage was quite mature when harvested and
the leaves made up a relatively small proportion of the total
forage. This hay was offered unchopped to mules once daily in
an open trough, and the refused portion was weighed. Shat-
tered leaves were gathered from the floor of the storage loft
and offered separately. The mules ate 53 percent of the leaves
but only 26 percent of the hay.
C. intermedia of the 1934 crop was harvested at three stages
of development and cured by several methods. The cured hay
was stored in a shed and subsequently offered to mules. The
refused portion of the hay was weighed as before. Although
relatively small amounts were available for use it was notice-
able that the mules preferred the leaves and finer stems. The
hay from the plants cut at the bud stage was more palatable

TABLE 15.-EFFECT OF STAGE OF DEVELOPMENT OF Crotalaria intermedia UPON
THE AMOUNT OF HAY OR SILAGE EATEN BY MULES OR CATTLE.
Forage Forage Proportion
Stage of Development Year Animals Offered Refused Consumed
pounds pounds percent
C. intermedia hay
fre-bud stage ............. 1934 mules 160 68 58
Bud stage ...................... 1934 mules 358 112 69
Early pod stage.......................1932 cows 4,476 2,307 48
Pod stage, entire plant.......... 1933 mules 3,459 2,576 26
Pod stage, shattered leaves .1933 mules 91 43 53
C. intermedia silage
Pre-bud stage ............ ......... 1934 cattle* 972 8 99
Bud stage ....... ... ....... 1934 cattle 1,008 285 72
Bloom ................................ 1934 cattle 1,056 351 67
Pod stage ............... ........... 1934 cattle 719 448 38
*Fifteen Jersey cows ano 34 grade Hereford and native beef cattle were used in
the silage palatability trials.






Florida Agricultural Experiment Station


than from those after the blossoms opened, as shown by the
amounts consumed. (See Table 15.)
Stage of development as it relates to palatability of the
C. intermedia hay and silage is an important factor in the utiliza-
tion of this plant as a forage crop. A summary of the observa-
tions with mules and with cattle is presented in Table 15.

IV. COMPARATIVE FEEDING TRIALS WITH DAIRY COWS
C. intermedia Silage versus No. 1 Federal Grade Alfalfa Hay for
Milk Production.-Since C. intermedia planted during the spring
attained such a stage of development in Florida that it was ready
to harvest during the summer rainy season (5), it was deemed
advisable to make comparative feeding studies for milk pro-
duction, using the crop as silage. Three comparative feeding
trials were conducted by the standard double-reversal method
(15) using eight Jersey cows per trial. These cows were divid-
ed into two equal lots according to age, weight, milk yields, stages
of lactation and gestation. The feeding trials were of 90 days'
duration, divided into three 30-day periods, of which 10 days
were preliminary and 20 days were experimental.
Rations were calculated at the beginning of each 30-day
period to meet requirements of the Morrison standard (18).
C. intermedia silage was offered at the rate of 4 pounds and al-
falfa hay at the rate of 11 pounds per 100 pounds live weight.
Corn silage was limited to 2 pounds per 100 pounds live weight.
The concentrates, consisting of 4 parts of corn feed meal, 2 parts
of wheat bran and 1 part of cottonseed meal (41% total crude
protein), were offered in amounts to provide those nutrients
not supplied by the roughage. The cows were weighed on three
consecutive days at the beginning and end of the preliminary
periods, and again at the end of each experimental period. Ex-
cept at milking time the cows were kept in a dry lot in which
common salt, bonemeal and water were accessible at all times.
Complete milk and feed records were obtained and fat produc-
tion was estimated, based on individual 5-day composite milk
samples taken in the middle of each experimental period.
The comparative feeding trials during the winters of 1933-
34 to 1935-36 were attended with particular success. Not a cow
was off-feed, nor did a single record have to be discarded. A
total of 24 cow records were available for tabulation and for







Crotalaria for Forage


computation of the comparative feeding value of the C. intermedia
silage and No. 1 green federal grade alfalfa hay. The alfalfa had
been purchased on the Kansas City market.
The milk yield, changes in body weights, and feed con-
sumption were calculated according to the standard formula for
this purpose:
Period IIa + Period la + Period IIIa P b Period Ib + Period IIIb
2 2
In applying the above formula, "a" designated the periods du-
ring which C. intermedia silage was fed, while "b" represented
all periods in which alfalfa hay was fed. The results of this cal-
culation are given in Table 16.
TABLE 16.-TOTAL FEED INTAKES, MILK YIELDS, AND CHANGES IN BODY WEIGHTS
OF THE COws DURING THE DOUBLE-REVERSAL FEEDING TRIALS
Feed Consumption* Total Production







1933-1934 8 3,458.5 ........... 2,610.5 1,115.0 1,622.65 94.18 160.5
8 1,420.5 2,842.0 91.0 1,790.40 107.74 130.5





which either the silage or the alfalfa hay was fed.

It can be seen by a glance at Table 16 that the cows con-
sumed more alfalfa hay and corn silage, yielded more milk and

butterfat, but gained less weight per group while on that ration
than did the same animals when C. intermedia silage was offered.
1933-1934 8 3,458.5 ......... 2,610.5 1,115.0 1,622.65 94.18 160.5
8 .......... 1,420.5 2,842.0 915.0 1,790.40 107.74 130.5
1934-1935 8 3,314.3 .... 2,348.5 1,172.8 1,883.85 93.61 125.5
8 ,........ 1,515.3 2,792.6 829.0 2,136.55 118.38 76.0
1935-1936 ... 8 3,290.2 ...... .... 2,996.7 1,337.5 2,234.00 113.70 212.0
8 ........ 1,340.0 3,329,1 1,200.0 2,405.65 123.75 155.0



When the feed consumption were calculacomputed forth da per 100 poundsuring
which either the silage or the algroupalfa hay s were given equal weighting
on this can basis, it was possiblglance to calculate the total digestible con-
sumed more alfalfa hay and corn silage, yielded more milk and



butterfat, but gained less weight differ groupenes in consumption of the
basal ration, and tsam animallow for these intermdia s of No. 1 alfalfa hay,ered.
When the feed consumption was computed per 100 pounds
of milk produced and the groups were given equal weighting
on this basis, it was possible to calculate the total digestible
nutrient equivalent of any differences in consumption of the
basal ration, and to allow for these in terms of No. 1 alfalfa hay,
as shown in Table 17. Likewise, with average body weights,
milk yields and fat percentages for each group, it was possible to
calculate the nutrient requirements and to compare these with
the nutrient intakes from the feeds consumed. All of these com-
parisons are given in this table. The average daily gains were
computed, but no allowance was made for them.










TABLE 17.-SUMMARY OF FEEDING TRIALS COMPARING Crotalaria intermedia SILAGE WITH NO. 1 GREEN FEDERAL GRADE ALFALFA
HAY FOR MILK PRODUCTION.


Feeds Consumed per 100 Lbs of
Milk Produced


'U








1 867 10.14 5.80
1 828 11.19 6.02
2 870 11.77 4.97
2 844 13.35 5.54
3 870 13.96 5.09
3 847 15.04 5.35
W weighted average .................
D difference* ...............................
Difference*................ ...


7-5








213.14

175.93

147.27

178.78

178.78


79.34

70.92

55.70

68.65

68.65


0

7cc


160.88
158.74
124.66
130.71
134.14
138.38
139.89
142.61

2.72


68.71
51.11
62.25
38.80
59.87
49.88
63.28
46.60
16.68


Requirement per
100 Lbs. Milk


9.86
8.94
8.50
7.49
7.16
6.65


ez







110.21
102.44
96.84
88.91
87.98
84.60


Nutrients Provided
by Feed



U'U






14.66 109.03
17.20 113.46
12.14 88.39
13.77 94.50
13.60 98.21
14.66 10.0384
17.20 113.46
12.14 88.39 T
13.77 94.50 S.
13.60 98.21 tq
14.66 104.84

------------------- (a


*Difference in feed intakes in relation to production of 100 lbs. of milk above maintenance requirements were computed as follows:
2.72 lbs. corn silage of this chemical anaylsis, is equivalent to 0.61 lbs. T. D. N.
16.68 lbs. mixed grain of this chemical analysis, is equivalent to 12.90 lbs. T. D. N.
The difference in T. D. N. intakes from corn silage and mixed grain then is 12.29 lbs. T. D. N., which in turn is equivalent to the
T. D. N. contained in 21.39 Ibs. of this alfalfa hay, 68.65 lbs 21.39 lbs., leaves a difference of 47.26 lbs. of alfalfa hay. 178.78 lbs. of
C. intermedia silage then was equivalent in feeding value for milk production, to 47.26 Ibs. of alfalfa hay, neglecting any changes in
body weights of the animals. On the dry matter basis then, 100 lbs. of this alfalfa hay was the feed equivalent of 107.3 lbs of
C. intermedia silage, when fed with the basal ration in this experiment. On the fresh moist basis as fed, 1.0 lbs. of air dry No. 1 green
federal graded alfalfa hay was equivalent to 3.78 lbs of C. intermedia silage. The gains in body weight, for which no allowance was
made amounted to .062, .046, .042, .022, .059, and .040 lbs. per animal daily in the respective trials above.







Crotalaria for Forage


In the final computation it was found that 179 pounds of
C. intermedia silage was equivalent in feeding value to 47 pounds
of No. 1 alfalfa hay, neglecting the changes in body weight. On
this basis 3.78 pounds of fresh C. intermedia silage were equivalent
to 1.0 pounds of air dry No. 1 green federal grade alfalfa hay,
as used in these trials.
It should be pointed out that the cows received an excess of
protein in every instance, but the rations containing C. intermedia
silage during the first two trials provided slightly less total di-
gestible nutrients than the requirements of the cows, calculated
according to the Morrison standard. Furthermore, the consump-
tion of C. intermedia silage was lower than desired. The total
digestible nutrients from this feed supplied only about one-fifth
of the total digestible nutrients intake of the cows, as compared
with nearly two-fifths from the alfalfa hay.
As a further check of the relative palatability of the
C. intermedia silage, the percentages of the several feeds refused
by the cows were calculated, and arranged in tabular order. It

TABLE 18.-THE PERCENTAGE OF EACH FEED REFUSED BY INDIVIDUAL COws DURING
THE COMPARATIVE FEEDING TRIALS WITH C. intermedia SILAGE VERSUS No. 1
GREEN ALFALFA HAY.
C. intermedia Corn Mixed Alfalfa
Silage Silage Grain Hay
Percentage Refusals
.7 .... .54
6.0 .36 ..... 1.3
10.2 .9 .... 1.5
10.6 2.2 .... 1.6
13.0 3.6 .. 2.3
17.1 3.97 .. 2.4
17.4 4.9 ..... 3.1
18.1 5.0 ..... 3.6
18.7 6.2 ...... 3.9
18.8 6.5 .... 4.1
18.9 6.95 ...... 4.45
20.3 7.1 .... 5.6
20.4 7.5 .06 5.8
21.3 7.5 .15 5.8
25.6 8.0 .15 6.6
26.4 8.0 .29 11.6
27.7 8.2 .38 13.2
28.3 8.7 .5 13.4
28.7 8.8 .7 16.1
29.6 8.9 1.4 16.1
34.7 9.9 3.5 17.9
35.2 10.3 7.2 18.1
47.1 11.1 8.4 27.9
47.5 13.0 9.9 33.0
Average 22.59 6.57 1.36 8.91
Median 20.3 7.1 0.00 5.6






Florida Agricultural Experiment Station


was noted in particular that the mixed concentrates and corn
silage were the most palatable feeds used in the trials. Alfalfa
hay ranked next in order with only about one-third the per-
centage of refusal noted with the C. intermedia silage. These re-
fusals of feeds are shown in Table 18.
Mineral Consumption of Cows During Feeding Trials.-
Common salt and finely ground feeding bonemeal were access-
ible in a covered mineral box in the dry lot where the cows were
kept. No mineral matter was mixed with the concentrates du-
ring the feeding trials. It has been the practice to mix 1 percent
of common salt and 2 percent of bonemeal with the concentrates
ordinarily fed to this herd. Only small amounts of these two
supplements were placed in the box at one time so as to reduce
losses by wind or weather, and also to prevent the bonemeal
from becoming stale while in the box. Unused supplement was
weighed back at the close of each 90-day period. Records of
consumption are given in Table 19.

TABLE 19.-SALT AND BONEMEAL CONSUMPTION OF 24 JERSEY COws WHILE ON
DOUBLE-REVERSAL FEEDING TRIALS COMPARING C. intermedia SILAGE WITH
No. 1 GREEN FEDERAL GRADE ALFALFA HAY.

Year Number Avg. Live Avg. Daily Total Consumption
of Cows Weight Milk Yield Salt Bonemeal
pounds pounds pounds pounds
1933-1934 8 848 10.7 88.1 23.0
1934-1935 8 857 12.6 76.7 21.1
1935-1936 8 859 14.5 85.1 12.1
Average consumption per cow per month ....... ..... 3.47 0.78

Effect of Feeds on Flavor of Milk.-The silage and other
feeds were placed in the manger before the cows entered the
stable at milking time. Fourteen samples of milk were obtained
from cows used in the feeding trial, and from others in the Sta-
tion dairy herd. Four cows from which milk samples were ob-
tained on March 18, 1935, received C. intermedia silage, four
others received No. 1 green alfalfa hay, and six other cows
grazed on permanent pasture grasses. All of these animals re-
ceived a basal ration of corn silage and mixed concentrates.
The milk samples were taken from the milking machine, capped
while warm, without aeration, and chilled in a cold room at
40-45 Fahrenheit. Each sample was given a key number by one
man and re-keyed by another, so that no person testing the milk







Crotalaria for Forage


knew the source of any sample. These samples were judged for
odor and flavor by 12 persons. Based on their independent opin-
ions no flavor or odor characteristic of C. intermedia silage was
detectable. Some feed flavor was detected in the milk of the
cows receiving alfalfa, and less in the milk from cows on grass
pasture.

V. ENSILING STUDIES WITH CROTALARIAS
Ensilability of Several Crotalarias in Laboratory Silos.-
Four small monolithic concrete pit silos were constructed, hav-
ing approximately one-ton capacity. These silos had an inside
diameter of 43 inches and were between 74 and 81 inches in
depth. Each silo was filled with one species of crotalaria cut
into 11/2-inch lengths in a silage cutter, weighed, and packed in
the silo by tamping and tramping the cut forage. A piece of moist
burlap was placed over the top surface; additional cut material
was packed above this burlap, and the whole was covered with
approximately two feet of earth, cone-shaped to shed rain.
A 10-kilogram sample of the cut forage was placed in a
muslin bag near the center of the silo at the time of filling, and
a corresponding sample of the fresh material was taken for chem-
ical analysis. These samples were used to determine the ensiling
changes with each forage (20). Nine species were handled in this
manner, including C. anagyroides, C. goreensis, C. grantiana, C. in-
cana, C. intermedia, C. lanceolata, C. spectabilis, C. striata, and C. usara-
moensis. The ensiling interval with the several species varied
from 49 to 81 days.
The four silos were opened at one time. All spoiled and
sound silage beneath the burlap was weighed when removed.
Measurements of depth of the silage were made daily, on which
to base calculations of its density.
As mentioned previously, these silages were used to deter-
mine the relative palatability of the several species of crotalaria
when offered to cattle during 1932 and 1933. Whatley's Prolific
field corn was used to fill one silo. The species preferred in 1932,
and in the first trial during 1933, were used along with the two
remaining species for the final trial.
All nine species of crotalaria ensiled satisfactorily in the
small silos by the method described. The majority of these silages
had a desirable light green color, except C. spectabilis, which was














TABLE 20.-CHEMICAL COMPOSITION OF THE FRE SH GREEN FORAGE OF NINE SPECIES OF CROTALARIA.


Cd 0n
a Vdo
*c0 q1 ~It


C. spectabilis
C. striata
C. incana
C. grantiana
C. goreensis
C. anagyroides
C. usaramoensis
C. lanceolata
C. lanceolata
C. intermedia
C. intermedia
C. intermedia
C. intermedia
C. intermedia
C. intermedia
C. intermedia*
C. intermedia*
C. intermedia*


.. 20.86
..... 25.92
.... 24.32
...... 21.10
...... 27.90
...... 29.06
.... 22.64
...... 21.56
...... 32.94
.... 25.00
30.60
pre-bud 22.94
bud 22.56
bloom 26.25
pod 28.40
bud 30.08
bud 21.72
bud 24.41


Composition of the Dry Matter


10.00
17.03
11.40
13.38
10.36
12.56
18.83
18.33
12.22
12.04
13.04
19.37
16.90
14.65
11.85
13.34
16.79
13.91


U U

1.38 41.70 40.03 6.89
2.04 39.14 37.90 3.89
1.27 46.40 35.12 5.81
2.39 30.97 37.69 15.57
1.67 48.26 34.42 5.29
2.08 40.17 40.33 4.86
2.14 29.69 40.63 8.71
2.77 26.56 42.82 9.52
2.33 45.26 36.76 3.43
1.64 41.00 40.08 5.24
2.06 42.53 38.89 3.48
1.44 31.58 33.75 13.86
1.77 41.99 35.45 3.89
2.15 44.86 34.72 3.62
1.48 47.75 35.13 3.79
2.29 40.06 38.26 6.05
2.48 38.37 37.59 4.77
2.19 39.47 40.37 4.06


s g




1.197 .416 .336
.827 .464 .279
.670 .410 .311
.890 .192 .327
.407 .179 .273
.530 .218 .273
.921 .209 .339
.842 .253 .410
.447 .223 .219
.610 .331 .261
.628 .233 .224
.791 .447 .397
.736 .504 .262
.661 .426 .236
.622 .351 .193
.698 .232 .240
.743 .280 .204
.652 .293 .229


*During three years the analyses representing forage placed in the upright concrete silo are the average of five samples; all others
represent single samples.


9/22/32
9/23/32
9/22/32
7/25/33
9/28/33
9/28/33
7/25/33
7/25/33
9/28/33
9/23/32
9/28/33
7/30/34
8/24/34
9/14/34
10/3/34
9/12/33
8/29/34
9/11/35











TABLE 21.--CHEMICAL COMPOSITION OF THE SILAGE MADE FROM NINE SPECIES OF CROTALARIA.

Composition of the Dry Matter


C. spectabilis ............ 88 Laboratory 18.16
C, striata ............ 86 23.42
C. incana ... .... 87 23.54
C. grantiana .. ........ 50 20.18
C. goreensis ............ 53 24.30
C. anagyroides ........... 53 26.31
C. usaramoensis ........... 51 22.32
C. lanceolata ............ 50 20.07
C. lanceolata ........... 53 31.42
C. intermedia ........... 87 22.36
C. intermedia ........ 3 28.37
C. intermedia pre-bud 134 23.33
C. intermedia bud 106 19.99
C. intermedia bloom 85 24.56
C. intermedia pod 68 26.91
C. intermedia* bud .... Upright* 27.43
C. intermedia* bud .. Upright* 18.87
C. intermedia* bud .... Upright* 22.19


4--g .~g

10.18 2.08 46.29 33.95 7.50
14.20 3.24 44.39 33.74 4.43
9.94 2.43 47.92 33.08 6.63
8.71 2.77 40.19 27.07 21.26
8.13 2.19 49.11 34.73 5.84
10.74 2.67 48.31 33.18 5.10
16.61 3.80 34.10 34.47 11.02
16.27 3.78 31.00 36.38 12.57
10.84 2.44 51.50 32.00 3.22
10.74 2.91 46.80 33.82 5.73
12.27 2.25 49.30 32.19 3.90
17.22 3.55 32.59 32.67 13.07
16.01 3.24 45.77 30.52 4.46
13.79 2.80 47.59 31.80 4.02
10.69 1.70 53.06 30.08 3.48
12.12 2.57 46.22 32.45 6.64
12.64 3.36 45.61 32.20 6.10
12.45 2.72 44.91 35.14 4.78


1.282
.811
.721
.932
.483
.495
.012
.066
.448
.610
.669
.773
.802
.709
.428
.758
.004
.759


E




.423 .411
.434 .279
.381 .305
.212 .302
.220 .313 .
.224 .257
.231 .345 '
.240 .377
.219 .224 T
.361 .276
.245 .243 V
.404 .410 t
.506 .288
.481 .284
.370 .217
.217 .257
.407 .238
.373 .285


*The composition of silage in the upright concrete silo represents the average of duplicate analyses from each of five separate bags;
all others represent duplicate analyses from single sample bags of silage located in the middle of each of the one-ton concrete laboratory
pit silos.






Florida Agricultural Experiment Station


quite dark. Cattle refused to eat the silage of only one species-
C. striata-even though it had a green color and not unpleasant
odor. The silage of C. intermedia was quite palatable and of good
quality. The silage from these legumes was less acid than corn
silage, the pH values (hydrogen-ion concentrations) ranging be-
tween 4.6 and 5.5, as compared with 3.47 in the Whatley's Prolific
corn silage (20).
The chemical composition of the dry matter in the freshly-
cut crotalarias, and of the silage taken from the 10-kilogram
sample bags, is given in detail in Tables 20 and 21. In general,
the crotalarias contained between 10 and 18 percent of crude
protein in the dry matter. Their calcium contents were fairly
high, even when grown on acid sandy soils. The content of crude
fiber was quite high as compared with other legumes grown as
commercial hay crops. The composition of the silages is dis-
cussed further in the next section of this bulletin.
Stage of Development of C. intermedia as It Affects Palatabil-
ity and Ensilability in the Laboratory Silos.-During the palatab-
ility grazing trials in 1932 one end of all rows of crotalaria was
mowed at a height of 8 to 10 inches above the ground at the
conclusion of the first grazing period. The two cows in the fol-
lowing grazing period preferred new growth on the mowed
plants over that of the more mature ones. With the hay grown
in 1934 and cut at different stages of development mules ate
somewhat larger proportions of that harvested in the bud than
in the pre-bud stage, or of the more mature forage. There was
excessive refusal of both stems and leaves of C. intermedia hay
that had been harvested in the pod stage (see Table 15).
C. intermedia was ensiled in the one-ton silos during 1934 in
four different stages of development; namely the pre-bud, bud,
bloom and pod stages. The silos were opened on December 5,
1934, and weighed amounts of each silage were offered simultan-
eously to 15 Jersey cows and 34 grade Hereford and native cat-
tle. These cattle showed a definite preference for the silage made
from the younger forages, as shown in Table 15. The propor-
tions of the four silages eaten by these 49 animals were: pre-bud
stage, 99 percent; bud stage, 72 percent; bloom stage, 67 percent,
and that in the pod stage of maturity, 38 percent. If smaller
amounts of silage had been offered, it is possible that less would
have been refused by the cattle.







Crotalaria for Forage


An examination of the chemical analyses, on the dry mat-
ter basis, of the samples of fresh C. intermedia from which these
silages were made (see Table 20), shows that the early-cut forage
contained over 19 percent of crude protein, 31.6 percent of fiber,
34 percent of nitrogen-free extract, and a high percent of ash.
(Rain fell during the harvest and part of the plants were spatter-
ed with sand.) The C. intermedia harvested in the early pod stage
contained less than 12 percent of protein and over 47 percent of
crude fiber. These differences in composition are considered to
be a cause of the reduced palatability of the late-cut forage.
Ensiling Efficiency of Concrete Silos.-The ensiling efficien-
cy with crotalaria in the one-ton laboratory silos, and of
C. intermedia in a 20-foot upright monolithic concrete silo, was
determined. Methods of handling the forage and samples con-
nected with the one-ton silos have been described.
An upright concrete silo 20 feet in height and 10 feet in di-
ameter was filled with C. intermedia cut into three-fourths inch
lengths, and tramped during the filling process. Each year five
10-kilogram samples of freshly cut C. intermedia were placed in
moist muslin bags distributed at intervals in the silo, and cor-
responding 10-kilogram samples were taken to represent the fresh
forage at time of ensiling. Two-ply roofing paper was placed
over the top of the weighed forage and about two tons of cut
crotalaria were packed over this to seal the silo.
This silo was opened after ensiling periods of 82, 96, and 79
days respectively, in the three years that it was used during the
investigation. All sound and spoiled silage was weighed when
removed, and depth of the silage was measured at 5-day inter-
vals. The total weights of forage ensiled and silage removed are
given in Table 22.

TABLE 22.-Amrou-Ts oF C. intermedia IN TIE UPRIGHT SILO, USED IN INVESTIGA-
TIONS OF THE DIGESTIBILITY, COMPARATIVE FEEDING VALUE, AND ENSILABILITY OF
THIS CROP.
Stage of
Develop- Forage Ensiling Feeding Sound Silage Spoiled Silage
Year ment Ensiled Period Period Removed Removed
pounds days days pounds pounds percent
1933 bud 50,220 82 131 37,762 7,775 17.1
1934 bud 60,415 96 157 59,327 348 .6
1935 bud 48,170 70 140 42,868 1,229 2.8

The samples of silage in the muslin bags were recovered and
their analyses used in calculating the efficiency of preservation







Florida Agricultural Experiment Station


of nutrients in the silo. Analyses of the five samples of fresh for-
age and of silage from the muslin bags were averaged for each
year. The averages are presented in Tables 20 and 21.
Total weights of the green forage ensiled, of the sound silage
removed, and chemical analyses of the corresponding samples,
were used in calculating the percentage recovery of nutrients in
the silage. These weights and percentage recoveries are shown
in Table 23. The one-ton silos, with the method of packing and
sealing used, had less surface and edge spoilage (none in some
cases), and preserved the nutrients more efficiently than did the
upright concrete silo.
A comparison of the relative efficiency of the laboratory silos
and the upright concrete silo in preserving the nutrients of the
crotalaria forage in the form of sound silage, is as follows:
Efficiency of preserving nutrients as silage.
Dry Crude Ether Crude N-free
Type of silo Matter Protein Extract Fiber Extract Ash
percent percent percent percent percent percent
Laboratory silo 87 76 131 98 76 97
Upright silo 78 67 98 91 68 94

The apparent increase in ether extract is due to the forma-
tion of ether-soluble substances by the ensiling process. Little
loss occurred in the ash and in the crude fiber, as would be ex-
pected. Apparently the losses of crude protein and of nitrogen-
free extract are of about equal magnitude in the ensiling of this
group of legumes. These losses were roughly one-fourth of the
protein and nitrogen-free extract in the small silos and one-third
in the larger silo where edge and surface spoilage affected the
efficiency to a greater extent. Although these data are based on
15 records with the small silos and only three records with the
larger silo, yet 15 pairs of samples were involved in each com-
parison.
Densities of Crotalaria Silages and Silo Capacity with C.
intermedia Silage.-Crotalaria differs from corn, the sorghums, and
many other plants that have been ensiled commercially, in that
the stem structure is less pithy. No seed is contained in the crop
when it has reached the stages of development desirable for har-
vest as silage. At this earlier stage of development usually
more water is present in the plant than in many silage crops.
These facts made it desirable to obtain records as to the capacity








Crotalaria for Forage


TABLE 23.-EFFICIENCY OF PRESERVING THE NUTRIENTS OF CROTALARIAS, BASED ON
THE TOTAL WEIGHTS AND COMPOSITION OF THE FORAGE ENSILED AND OF THE
SOUND SILAGE REMOVED FROM THE SILOS.

Dry Matter Recovery of the Nutrients
In Forage In Silage Crude Ether Crude N-free
Species Ensiled Removed Protein Extract Fiber Extract Ash
pounds pounds percent percent percent percent percent
Comparison of Species
C. anagyroides 707.6 621.2 75.08 112.70 105.58 72.23 92.12
C. goreensis 669.9 564.2 66.10 110.55 85.71 84.99 92.97
C. grantiana 580.3 466.7 52.36 93.22 104.38 57.76 109.82
C. incana 507.8 436.2 74.90 164.34 88.72 80.91 98.03
C. intermedia 631.5 520.8 73.56 146.23 94.13 69.58 90.18
C. intermedia 637.7 567.3 83.71 97.18 103.31 73.64 99.73
C. lanceolata 604.3 564.0 82.84 127.36 108.93 79.29 122.18
C. lanceolata 710.5 664.3 82.93 98.00 106.67 81.53 87.77
C. spectabilis 544.2 404.4 75.65 111.98 82.49 63.02 80.88
C. straita 627.3 543.9 72.30 137.66 98.33 77.19 98.73
C. usaramoensis 641.2 624.5 85.91 172.96 111.86 82.68 123.23
Stage of Development
C intermedia
pre-bud 587.5 555.7 84.09 233.22 97.61 91.56 95.33
bud 580.2 452.3 73.84 142.75 84.97 67.11 89.37
bloom 686.4 616.6 84.56 117.01 95.30 82.28 99.76
pod 643.0 583.5 81.87 109.77 100.85 80.03 83.34
Average 624.0 545.7 76.76 131.67 97.91 76.12 97.56
Twenty-Foot Upright Silo
C. intermedia
bud* 15,106 10,358 62.30 76.95 79.11 58.16 75.26
bud* 13,122 11,195 64.23 115.59 101.41 73.08 110.71
bud* 11,758 9,713 73.94 102.60 93.99 71.91 97.26
Average 13,329 10,422 66.82 98.38 91.50 67.72 94.41
*Average of five fresh forage and five silage samples used in computation.

of silos for this crop, and the relative density of the silage at dif-
ferent depths.

The depth of settled silage was measured in each of the silos
when opened. The one-ton silos were measured at least once
daily as the silage was removed. The depth of silage in the
upright 20-foot silo was measured at five-day intervals. All cal-
culations were based on the total weight of silage removed and
the number of cubic feet occupied by it. The relative densities of
these silages in the one-ton silos and in the upright silo are pre-
sented in Tables 24 and 25.








56 Florida Agricultural Experiment Station


TABLE 24.-WEIGIIT OF CROTALARIA SILAGES IN POUNDS PER CUBIC FOOT, AS DETER-
MINED IN ONE-TON CONCRETE PIT SILOS.
Depth Weight of Settled Silage per Foot in Depth of the Silo
Species Settled First Second Third Fourth Fifth Sixth
inches pounds pounds pounds pounds pounds pounds
Comparison of species
C. anagyroides 1.0 32.52 33.43 34.34 35.24 36.18 36.85
C goreensis 4.0 33.31 34.36 35.40 36.43 37.70 39.80
C. grantiana 22.8 43.89 45.68 49.06 50.41 52.79* ........
C. incana 21.0 38.71 40.52 41.17 41.53 ....... .......
C. intermedia 13.8 36.20 38.09 39.28 40.76 42.80
C. intermedia 7.0 32.29 33.25 34.00 34.44 34.92
C. lanceolata 9.3 45.06 47.35 49.63 51.91 54.92 58.66*
C. lanceolata 1.0 32.17 32.60 33.03 33.47 33.90 34.33
C. spectabilis 22.5 40.75 42.86 44.16 44.72 45.44* ........
C. striata 11.5 36.55 40.69 43.15 43.92 44.16
C. usaramoensis 7.5 43.55 44.13 44.71 45.30 45.88 47.87*
Stage of Development
C. intermedia
pre-bud 9.8 31.24 43.66 47.25 48.51 49.28 ........
bud 23.0 44.23 45.87 46.89 50.93 54.97*
bloom 6.8 38.62 39.47 40.32 40.95 41.20 41.44
pod 4.5 35.53 35.81 36.09 37.13 37.54 38.37*
Whatley's Prolific
corn .0 32.07 32.12 32.23 32.44 32.65 32.86
*Gravitational moisture present.

TABLE 25.-CAPACITY OF AN UPRIGHT SILO 10 FEET IN DIAMETER, FOR C. intermedia
SILAGE, AS COMPARED WITI SOYBEAN AND CORN SILAGES.

Death Weight of Silage per Cubic Cumulative Weight of Silage in
Deph Foot in 10-Foot Silo
of
Silage C. intermedia Soybean** Corn*** C. intermedia Soybean** Corn***
Feet pounds pounds pounds tons tons tons
1 32.4 28.2 32.0 1.27 1.10 1.26
2 33.8 30.4 32.7 2.60 2.30 2.54
3 35.3 32.7 33.4 3.98 3.58 3.85
4 36.8 35.1 34.1 5.04 4.46 5.19
5 38.2 37.3 34.8 6.92 6.43 6.55
6 39.7 39.1 35.4 8.48 7.96 7.94
7 41.0 41.5 36.0 10.09 9.59 9.37
8 42.2 42.8 36.6 11.75 11.27 10.80
9 43.0 44.2 37.4 13.43 13.01 12.26
10 43.9 46.2 38.0 15.15 14.82 13.74
11 44.5 47.5 38.4 16.90 16.69 15.25
12 45.2 49.4* 38.8 18.67 18.63* 16.77
13 45.9 52.4* 39.2 20.48 20.68* 18.32
14 46.6 55.2* 39.6 22.30 22.85* 19.90
15 47.3 57.99* 40.0 24.16 25.09* 21.44
16 47.9 .. 40.2 26.04 ........ 23.00
20 .... 41.0 ........... .. 29.4
25 ...... 42.0 ............. 37.6
30 ...... 43.0 ........ ...... 45.9

*Gravitational moisture was present in the silage.
**Data taken from Florida bulletin 255 (7).
***Data of Eckles, Reed and Fitch (10).







Crotalaria jor Forage 57

Any gravitational moisture in the bottom layer of silage in
the silos was indicated by an asterisk in Tables 24 and 25.
C. intermedia silage has a density similar to that found with
soybean silage (7), and ranging up to 20 percent heavier per cub-
ic foot than corn silage. The C. intermedia packed more densely
than corn as depth in the silo increased. It was observed that
with the advance toward maturity and the decrease in water
content, the silage weighed less per cubic foot and did not settle
as much in the silo during the ensiling process.

TOXICITY OF CERTAIN SPECIES OF CROTALARIA
Species Reported in the Literature.-McKee and Enlow (19)
have summarized some of the literature prior to 1930 relative to
species of crotalaria known or reported to be toxic to livestock.
Four species of crotalaria have been proved definitely toxic to
animals. Bessey (8) showed C. sagitallis L. to be the cause of
death among horses from "Missouri river bottom disease." Seeds
of C. juncea L., or sunn-hemp (4) were fed to a healthy mature
sheep in amounts of one-fourth pound daily for a period of 14
days and one-half pound daily for 12 additional days. Weakness,
a tucked-up appearance, and catarrh developed shortly after the
14th day. Death occurred on the 26th day. According to Burtt-
Davy (9) and Phillips (23), cattle fed C. burkeana Benth for 5
days became stiff in the joints, moved slowly, and finally became
unable to stand. The hoofs lengthened and broke and death
resulted from starvation.
Theiler (28) fed as much as 46 pounds of C. dura Wood and
Evans to horses in 23 days and observed symptoms of poisoning
in 16 to 80 days. The symptoms and lesions included fever, acute
polypnoea, and subsequent dyspnea, destruction of the respira-
tory epithelium, leading to a vicarious emphysema, granulation
tissue, and degeneration of the bronchii. A bull fed 2 pounds
daily died in 64 days, and an ox was killed in extremis on the 98th
day. Symptoms included complete loss of appetite, diarrhea
with dark colored feces, progressive weakness, and ultimate loss
of animation. Autopsy revealed cirrhosis of the liver, thickened
central veins, and fibrillar bundles which formed a lacework in
which blood collected.
C. globifera E. Mey, C. incana L., and C. striata DC., have been
indicated as possibly toxic to cattle, goats and sheep in certain







Florida Agricultural Experiment Station


countries. Observations in Florida cause one to question the
toxicity of the two latter species, since seeds of both have been
fed to chickens, and cattle ate the green forage, hay, and silage of
C. incana without visible ill effects. At several places in Florida
cattle have been known to eat C. striata in appreciable quantities
without harmful effects.
Toxicity of C. spectabilis for Cattle.-In this cooperative in-
vestigation of crotalarias as possible forage crops, observations
were made of 11 species between the years 1931 and 1935, as
green forage, silage, or artificially dried hays. Not all of the 11
species of crotalaria investigated were offered to cattle in the
three kinds of roughage-green forage, silage, and hay. The
kinds of roughage to which the cattle had access during the
palatability trials, are listed in Table 26.

TABLE 26.-RELATIVE LEVELS OF THE CROTALARIAS EATEN BY CATTLE WHEN GIVEN
ACCESS TO THEM.
Class of Roughage Offered
Artificially
Species Green Forage Dried Hay Silage
1931 1932 1931 1932 1932 1933
C. anagyroides H. B. K. xxx xx xx
C. goreensis Guill. and Perr. .. .. .. .. xx
C. grantiana Harvey xxx x xx xxx xx
C. incana L. xxxx xxxx xxxx xxxx xxx .
C. intermedia Kotschy xxxx xxxx xxxx xxxx xxxx xxxx
C. lanceolata E. Mey x xxx xxxx xxxx .. xxxx
C. maxillaris Klotsch xxx xx
C. retusa L. x .. ..
C. spectabilis Roth xx x x xxx xxx
C. striata D. C. x x x x x
C. usaramoensis Baker x xxx xxx xxxx xxxx
Species not available.
x Available, but not eaten.
xx Eaten sparingly.
xxx Eaten in reasonable amounts.
xxxx Eaten in considerable amounts.

Cattle were not observed to show abnormal symptoms (6)
in any of the feeding trials during which C. spectabilis was refused.
During the fall and winter of 1932 two yearling grade Hereford
steers and one heifer were used in a series of trials testing the
relative palatability of crotalaria hays. The consumption of
C. spectabilis during these trials is given in Table 27. This hay
was harvested and dried artificially on September 9, 1932. These
three animals were the first observed in the investigation to eat







Crotalaria for Forage 59

this species as hay in any appreciable amounts. They took in-
creasing amounts as the trials progressed. The last hay palatab-
ility trial terminated on December 27, 1932. A decreased appe-
tite was evident in these three animals shortly prior to that date,
and total loss of appetite occurred soon. Blood was passed in the
feces, and some nasal hemorrhage occurred. The animals died
on January 7, 18, and 20 respectively.

TABLE 27.-CONSUMPTION OF ARTIFICIALLY-DRIED C. spectabilis HAY*, AND ITS
ORDER OF PREFERENCE WHEN OFFERED TO THREE YEARLING CATTLE ALONG WITH
HAY OF SEVEN OTHER SPECIES OF CROTALARIA.
C. spectabilis Hay
Dates of Trials Offered Refused Order of Preference
1932 pounds pounds
Nov. 16 23 13.3 16.3** 7th
Nov. 23 29 15.2 8.6** 5th
Nov. 29 Dec. 5 13.2 1.6 6th
Dec. 6 12 24.4 2.6 5th
Dec. 12 19 28.9 2.5 5th
Dec. 19 23 9.6 2.4 3rd
Dec. 23 27 27.3 0.0 3rd
*These three animals died of C. spectabilis poisoning on January 7, 18, and 20,
1933, respectively.
**Weight of refusal affected by rain.
The autopsy findings of Thomas, Shealy and Ahmann* were
as follows:
"All mesenteric and body fat, the pericardium, gallbladder,
and mucosa of the small intestines showed petechial hemorrhag-
es. Ecchymoses were noted in the anterior portion of the front-
al sinus, mucosa of the trachea, small intestines, and bladder.
Blood clots were observed in the posterior part of the frontal
sinus. The heart showed endocarditis, myocarditis and pericar-
ditis. The liver was finely mottled, red and maroon. The spleen
was slightly enlarged. Edema occurred in the wall of the abo-
masum. The large intestines contained an abundance of clotted
blood. The brain was congested with gelatinous material in the
sulci. The lymph nodes were slightly congested."
Typical lesions of the heart, liver, and mesentery of the
yearling steer affected with chronic C. spectabilis poisoning are
shown in Figure 16.
Since the three yearlings that died were the only cattle that
had eaten C. spectabilis hay in any appreciable amounts, this spec-

*Drs. E. F. Thomas and A. L. Shealy were assistant veterinarian, and animal
husbandman, respectively, while Dr. C. F. Ahmann was physiologist at the Florida
Agricultural Experiment Station.




Fig. 16.-Lesions of chronic C. spectabilis poisoning in cattle include petechial
hemorrhages in the intestines and mesentery (seen at the top), in the heart muscle
and fat (lower left), and liver (lower right). See page 59 for detailed autopsy records.

V E:; z. .' ,


n T 'w7


'"Cf)b',ll_~







Crotalaria jor Forage


ies was tested separately. For this purpose an eight months old
healthy native steer weighing 300 pounds was taken from an im-
proved grass pasture. C. spectabilis hay harvested and dried arti-
ficially on September 9, 1932, was offered, but the steer refused
to eat it. When the hay was ground and mixed with other
feeds, the steer still refused to eat it. A stomach tube was
passed, and weighed amounts of ground C. spectabilis hay were
suspended in water, and administered as a drench. The intake of
air-dry hay by this method was as follows:
December 12, 1933 0.5 pounds
December 13 4.0 pounds
December 14 3.5 pounds
December 15 1.9 pounds
Total 9.5 pounds
The steer lost a small amount of blood by nasal hemorrhage
and in the feces on December 14 and died at 4:30 P. M. the next
day. Death occurred quietly, the animal lying on its side, the
only struggle being a slight paddling of the feet. The autopsy
was made on the warm body before the onset of rigor mortis.
The course of this case was considered acute, in contrast with the
chronic type in the three preceding animals.
The blood did not clot readily when the jugular veins were
severed. The subcutaneous blood vessels, as well as those in the
adipose tissue and along the small intestines, were enlarged.
Petechial hemorrhages were present in the mesentery, on the
caecum, and in the gallbladder wall. The lumen of the lower
small intestines, the large intestines, and rectum contained blood.
The kidneys showed slight turkey-egg mottling and were dark
colored. The liver had a dark reddish-blue color and was quite
friable. The bile and urine appeared about normal in color. The
heart showed petechial hemorrhages in the coronary fat, on the
auricles, and along the interventricular groove. Parts of the
inner wall of the heart, the papillary muscles, and some of the
chordae tendinae showed marked hemorrhages.
Sanders, Shealy and Emmel (25) exposed cattle to daily
oral administrations of pulverized C. spectabilis seed and repro-
duced the clinical symptoms, gross and microscopic lesions which
had been observed under naturally occurring conditions. The
most prominent lesions in chronic cases were: edema of the
lungs, mesentery and intestinal wall, induration of the liver, hy-
pertrophy of the heart, and congestion of the kidneys and lungs.
In acute cases petechia and ecchymoses predominated.







Florida Agricultural Experiment Station


The observance of naturally occurring cases indicates that
cattle will graze C. spectabilis occasionally in quantities sufficient
to cause ultimate death.
Cattle eat the leaves and tender stems when in blossom.
Many more deaths have occurred from plants grazed during
the fall and winter. On this account C. spectabilis should not be
allowed to grow on areas over which livestock will graze later in
the same season.
In the palatability trials 37 head of cattle ate 2,206 pounds of
C. spectabilis silage during a 16-day period, or nearly 60 pounds of
silage per head. This was equivalent to 12.5 pounds of dry mat-
ter, or three-fourths of a pound of dry matter per head daily.
These cattle varied in age and weight, so that undoubtedly more
was eaten by some of them. No losses by death, or even sickness,
occurred although the feces were a dark color, corresponding per-
haps to the dark color of the C. spectabilis silage. Feces were not
examined closely at that time for detection of intestinal hem-
orrhage. Apparently the toxic principle (an alkaloid) is at least
partly destroyed during the ensiling process. This possibility has
not been verified.
Toxicity of C. spectabilis for Swine.-Emmel, Sanders and
Henley (13) observed C. spectabilis poisoning in nine hogs in one
herd which had access to a field containing a volunteer stand
of this plant. Many whole seeds passed undigested through the
alimentary tract. Comparable lesions were induced by feeding
the ground seeds of C. spectabilis experimentally. The outstanding
gross lesions were severe anemia, accumulations of fluid in the
abdominal and thoracic cavities, ecchymoses of the endocardium,
and gastritis. Deaths resulted from gastric hemorrhage.
Later these investigators (14) gave hogs access to a field of
peanuts and C. spectabilis, after frost had killed the plants. The
ground contained an abundance of C. spectabilis seeds. All animals
except one made satisfactory gains, and no deaths occurred. Some
lesions were present, however, on autopsy of the hogs. They
concluded that swine more commonly were poisoned by eating
the green plant in the late summer months when other forage
was sparse than by eating the seeds of C. spectabilis.
Toxicity of C. spectabilis for Chickens and Game Birds.-
Thomas (29) encountered cases of poisoning in chickens under
confinement which died after having access to litter containing
C. spectabilis seeds. This investigator force-fed whole seeds to






Crotalaria for Forage


chickens, doves, quail and wild turkeys and found that a high
rate of mortality occurred. However, the doves, quail and wild
turkeys did not eat C. spectabilis seeds scattered on the ground.
In studying the pathology of C. spectabilis poisoning in chick-
ens, Emmel (12) found that innumerable petechia in the serious
membranes and visceral fat characterized acute types of poison-
ing, while necrotic enteritis, ascites and anemia predominated in
chronic cases of poisoning. This investigator has observed cases
of natural poisoning in chickens from eating the green foliage
and seeds of this plant.
Toxicity with Horses and Mules.-Sanders (26) has ob-
served a number of cases of C. spectabilis poisoning, and even
deaths, in horses and mules during the fall and early winter on
several farms in the state.
Toxicity of Crotalaria retusa.-Cattle refused to eat C. retusa
in the form of green foliage. No other form of this plant was of-
fered to them. Emmel (11) fed definite numbers of seeds to 20
White Leghorn chickens and deaths resulted as follows:
Number of birds Number of seeds Time until death
4 100 Within 14 days
4 200 Within 10 days
7 10 on alternate days 14 to 40 days
5 Seeds in scratch grain 15 to 32 days
He described the lesions of this poisoning as necrotic en-
teritis, ascites, with an accumulation of a gelatinous mass ad-
hering firmly to the liver. The viscera were congested in acute
cases, but were pale in color in the chronic type of poisoning.
Isolation of the Toxic Principle.-An alkaloid named "mono-
crotaline" was isolated from the seeds as well as from the leaves,
stems and roots of C. spectabilis, by Neal, Rusoff and Ahmann
(22). The greatest concentration of alkaloid was found in the
ripe seeds. The purified crystals of the alkaloid melted between
196 and 198 degrees Centigrade. Combustion analyses of the
alkaloid crystals, by Dr. H. G. Shaw, showed 57.97 percent of
carbon, 7.85 percent of hydrogen, and 4.5 percent of nitrogen,
from which the formula CjeH2 O6N was calculated.
More recent work by Adams and associates at the University
of Illinois (1, 2, 3) has shown the formula for monocrotaline to
be C16H2aOeN. By extraction with 95 percent ethanol for 72
hours, they obtained yields as high as 3.2 percent monocrotaline
from C. spectabilis seed, and 1.89 percent from C. retusa seed.
Monocrotaline was found to undergo alkaline hydrolysis to ret-
ronecine, CsH1302N, and an optically inactive monobasic acid,






Florida Agricultural Experiment Station


CTHisOs, called monocrotic acid. By hydrogenolysis it yielded
retronecanol, CsH1O5N, and an optically active acid designated as
monocrotalic acid, CsH12O5. Upon treatment with alkali, mono-


F2*


^ ii;- .' *

h..2 C
-2ft 14.
`""11 ~~~ri '''o'j


4
tj [


I ',


Ip&, 9


Fig. 17.-Fine crystals of monocrotaline (x 14) recrystalized from chloroform
and larger crystals (x7) recrystalized from absolute ethyl alcohol.


F







Crotalaria for Forage


GENERAL SUMMARY AND CONCLUSIONS
The cattle preferred grasses to crotalaria when first given
access to them in the Crotalaria cafeteria. Only two of the experi-
mental cows refused to graze this crop while the plants were
young.
Crotalaria incana and C. intermedia were most outstanding of
the 11 species tested, from the standpoint of relative palatability.
C. incana became quite fibrous and dropped its leaves early in
the season. It produced an abundance of seed pods but they were
largely destroyed by pumpkin bugs and bella moths (Nezara
viridula and Utethesia bella).
C. intermedia possessed the combined qualities of reasonable
palatability and early and abundant seed production, was less
fibrous, and held its leaves reasonably late in the season. Lateral
buds sent out new growth after the top growth had been re-
moved. These characteristics led to the selection of C. intermedia
for subsequent cultural and feeding investigations.
Maximum yields of C. intermedia forage were obtained when
seeded at the rate of about 10 pounds per acre, but the optimum
quality resulted when 5 to 7 pounds of seed were drilled in
three-foot rows 8 pounds of seed per acre were broadcasted.
From 0.93 to 1.75 tons of air-dry hay were produced per acre on
a light Norfolk sand without fertilization.
C. intermedia, cured naturally, produced a coarse stemmy hay
from which the leaves had shattered badly.
When cut for silage the maximum tonnage of fresh forage
was harvested when the plants were in full bloom. The optimum
quality of forage was obtained when C. intermedia was cut in the
pre-bud stage. Only one-third as much green forage or one-
fourth as much dry matter was produced when harvested in
pre-bud as in the bloom stage.
The stage of development of crotalaria is an important
factor in its palatability. The fiber content of C. intermedia in-
creased rapidly between the bud and pod stages of development.
Cattle showed preference for the silage of C. intermedia when
it was harvested in the bud stage, or earlier. Hay which was
harvested in the pod stage, and offered as the sole feed, did not
maintain body weights of dry cows. Mules ate more of the hay
harvested before the bloom stage than of more mature forage.
That portion of the mature hay which cows consumed pro-
vided 4.9 percent of digestible crude protein and 47 percent of







Florida Agricultural Experiment Station


total digestible nutrients. An excessive refusal occurred from
the more mature plants, and the rate of consumption of the
hay was too irregular for the digestive coefficients to be repre-
sentative. C. intermedia hay, harvested later than the bud stage
of maturity, was not desirable as feed for cattle and mules.
C. intermedia silage harvested in the bud stage, with 27 per-
cent of dry matter, provided 2.1 percent of digestible crude pro-
tein and 10.7 percent of total digestible nutrients, as determined
in digestion trials with steers.
When eaten in the limited amounts that these Jersey cows
would consume with a basal ration of corn silage and mixed
concentrates, 107 pounds of dry matter in C. intermedia silage
were computed to be equivalent to 100 pounds of dry matter in
No. 1 green alfalfa hay for milk production. The cows refused
20 percent of the C. intermedia silage, 7 percent of the corn silage,
and 5.6 percent of the alfalfa hay.
Feed flavor was less perceptible in milk from cows receiving
C. intermedia silage and a basal ration of corn silage and mixed
concentrates during milking time than in the milk of cows fed a
similar basal ration with either No. 1 green alfalfa hay or young
mixed grasses.
The crotalarias ensiled satisfactorily when the dry matter
in the green forage varied between 20 and 32 percent. The silage
had a characteristic pungent odor and a reasonably green color.
The losses of nutrients in natural ensiling were mainly of
crude protein and nitrogen-free extract, these amounting to
33 and 32 percent, respectively, based on analyses of 15 paired
samples from freshly cut forage, and silage.
C. intermedia silage has an average density up to 13 percent
greater than that of average well-eared corn silage. Density of
the silage varies directly with the moisture content of the green
forage when ensiled.
Crotalaria spectabilis Roth. caused the deaths of cattle, mules,
and swine, in addition to fowls and game birds. It was found to
contain an alkaloid, named "monocrotaline", which caused death
in chickens. This alkaloid melted at 196-197 Centigrade. A
tentative molecular composition of C16H2606N was calculated
based on combustion analyses of the purified crystals, and a de-
termination of their neutral equivalent. Other workers have
shown the molecular formula to be C1,H2300N. The 24-hour le-
thal dose for chickens was found to be 65 milligrams of mono-






Crotalaria for Forage


crotaline per kilogram of live weight. The artificially dried hay
was highly toxic to cattle. Neither the green forage, hay, nor
silage of C. spectabilis should be offered to livestock, nor should
grazing be allowed over fields on which volunteer plants (or a
crop) of C. spectabilis have been killed by frost.
Crotalaria retusa L. seeds were found to cause death in chick-
ens. The presence of at least one alkaloid in the seed was dem-
onstrated, and at least one other may be present. Cattle did not
graze the forage of this species in the palatability trials.

ACKNOWLEDGMENTS
The Division of Forage Crops and Diseases, Bureau of Plant Indus-
try, of the United States Department of Agriculture, proposed the study
of the crotalarias as possible forage crops to the Florida Agricultural
Experiment Station, aided in planning the work and contributed to the
support of the project by furnishing seed, labor, and equipment. Dr. H.
Harold Hume, then assistant director of research, directed inter-depart-
mental relationships and contributed materially to facilities and plans
for the investigation.
W. E. Stokes represented the Agronomy Department in the study
of the production of crotalaria forage, in planning the work, arranging
for facilities, and otherwise aiding during the progress of the investiga-
tion.
Dr. A. L. Shealy aided in planning the project, provided certain
experimental animals, and participated in the toxicity studies. The
crops were ensiled under the supervision of Henry Zeigler, farm fore-
man.
Several persons assisted in the livestock phases of the investigation
C. R. Dawson aided with the initial observations on palatability of the
fresh crotalarias with dairy cows. Chemical analyses of feed and feces
samples from the digestibility and comparative feeding trials were made
by Will T. Dunn, L. L. Rusoff, Irving Rusoff and H. H. Hoffman. The
late Dr. R. M. Barnette determined the hydrogen-ion concentrations in
the press juice of the silages. The late Arlington Henley and Herbert
Henley cared for the animals in the digestibility and maintenance trials
and recorded the consumption of hay by mules. J. H. Warington, Hal
Warington, and S. L. Mimms aided with the cattle during the digestion
trials. H. H. Hoffman calculated many of the chemical analyses.
T. H. Rivers was responsible for feed and records with the dairy
cows during the first comparative feeding trial, and Jefferson Davis
during the second and third trials. W. W. Henley took weights of na-
tive cows on the grazing trial while Herbert Henley kept records of the
hay fed to mules.
L. L. Rusoff conducted certain important parts of the toxicity study.
Drs. E. F. Thomas and C. F. Ahmann aided in parts of these studies
with cattle, and with the monocrotaline alkaloid. Combustion analyses
of the monocrotaline on which the molecular constitution was postulated
were made by Dr. H. G. Shaw.
Some of the photographs were taken by W. A. Stenhouse of the
United States Department of Agriculture and W. E. Stokes. Micropho-
tographs were taken by R. K. Voorhees.






Florida Agricultural Experiment Station


LITERATURE CITED
1 Adams, R., and E. F. Rogers. The structure of monocrotaline, the alkaloid in
Crotalaria spectabilis and Crotalaria retusa. I. Jour. Amer. Chem Soc. 61:
2815-2819. 1939.
2. Adams, R., E. F. Rogers and F. J. Sprules. Structure of monocrotaline. II.
Monocrotic acid obtained by alkaline hydrolysis of the alkaloid Jour. Amer.
Chem. Soc. 61: 2819-2821. 1939.
3. Adams, R., E. F. Rogers and R. S. Long. The structure of monocrotaline. III.
Monocrotalic acid. Jour. Amer. Chem. Soc. 61: 2822-2824. 1939.
4. Anonymous. Poisonous properties of sunn-hemp (Crotalaria juncea). Rhodesia
Agr. Jour. 17: 497. 1920.
5. Arnold, P. T. Dix, W. M. Neal and R. B. Becker. Influence of arsenical dipping
on yield of milk by dairy cows. Jour. Dairy Sci. XV: 407-412. 1932.
6. Becker, R. B., W. M. Neal, P. T. Dix Arnold and A. L. Shealy, A Study of the
palatability and possible toxicity of 11 species of Crotalaria, especially of C.
spectabilis. Roth. Jour. Agr. Res. 50: 911-922. 1935,
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silage. Fla. Agr. Expt. Sta. Bul. 255: 3-24. 1932.
8. Bessey, C. E. The rattle-box (Crotalaria sagitallis Linn). Iowa Agr. Col. Dept.
Bot. Bul. 1884: 111-115.
9. Burtt-Davy, J. Notes on Crotalaria burkeana and other leguminous plants
causing death in stock. So. African Jour. Sci. 7: 269-277. 1911.
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silage. Mo. Agr. Expt. Sta. Bul. 164: 3-24 and Kans. Agr. Expt. Sta. Bul.
222: 3-22. 1919.
11. Emmel, M. W. The toxicity of Crotalaria retusa L. seeds for the domestic fowl.
Jour. Amer. Vet. Med. Assoc. 91 (n.a. 44) 205-206. 1937.
12. Emmel, W. M. The pathology of Crotalaria spectabilis Roth seed poisoning
in the domestic fowl. Jour. Amer. Vet. Med. Assoc. 90: (n.s. 43): 627-634.
1937.
13. Emmel, M. W., D. A. Sanders and W. W. Henley. Crotalaria spectabilis Roth
seed poisoning in swine. Jour. Amer. Vet. Med. Assoc. 86: (n.s. 39): 43-55.
1935.
14. Emmel, M. W., D. A. Sanders and W. W. Henley. Additional observations on
the toxicity of Crotalaria spectabilis Roth for swine. Jour. Amer. Vet. Med.
Assoc. 87 (n. s. 40): 175-176. 1935.
15. Forbes, E. B., and H. S. Grindley. On the formulation of methods of experimen-
tation in animal production. Bul. Natl. Res. Council, 6 (part 2): 33: 1-53.
1923.
16. Greshoff, M. Mittheilungen aus dem chemisch-pharmakologischen Laborator-
ium des Botanischen Gartens zu Buitenzorg (Java). Ber. Deut. Chem. Gesell.
23: 3537-3550. 1890.
17. Halten, W. Van. Korte anteekeningen over de groenbemesters welke van 1910
in den culturtuin werden aangeplant. Meded. Alg. Proofsta. Land. 16: 42-53.
1924.
18. Henry, W. A., and F. B. Morrison. Feeds and Feeding, 18th edit. (illus.)
Henry-Morrison Publishing Co. Pages 449, 726, and 746. 1923.
19. McKee, R., and C. R. Enlow. Crotalaria, a new legume for the South. U. S.
Dept. Agr. Circ. 137: 1-30. 1931.
20. Neal, W. M., and R. B. Becker. A type of laboratory silo and its use with
crotalaria. Jour. Agr. Res. 47: 617-625. 1933.
21. Neal, W. M., R. B. Becker and P. T. Dix Arnold. The digestbile nutrient con-
tent of Napier grass silage, Crotalaria intermedia silage and Natal grass hay.
Fla. Agr. Expt. Sta. Tech. Bul. 279: 3-26. 1935.
22 Neal, W. M., L. L. Rusoff and C. F. Ahmann. The isolation and some proper-
ties of an alkaloid from Crotalaria spectabilis Roth. Jour. Amer. Chem. Soc.
57: 2560-2561. 1935.







Crotalaria for Forage 71

23. Phillips. E. P. A preliminary list of the known poisonous plants found in
South Africa. So. Africa Bot. Survey Mem. 9: 1-30. 1926.
24. Rusoff, L. L. Unpublished work of the Nutrition Laboratory, Fla. Agr. Expt.
Sta.
25. Sanders, D. A., A. L. Shealy and M. W. Emmel. The pathology of Crotularia
spectabilis Roth poisoning in cattle. Jour. Amer. Vet. Med. Assoc. 89: (n.s.
42): 150-156. 1936.
26. Sanders, D. A. Unpublished data, Fla. Agri Expt. Sta.
27. Scott, J. M. Report of Animal Industrialist. Feeding tests. Fla. Agr. Expt.
Sta. Rpt. 1926-1927. Pages 27R-30R.
28. Theiler. Sir A. Jagziekte in horses (Crotalariosis equorum). Union of So.
Africa Dept. Agr., Dir. Vet. Res. Rpt. 7-8: 59-99. 1918.
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quail, turkey and dove. Jour. Amer. Vet. Med. Assoc. 85 (n.s 38): 617-
622. 1934.







72 Florida Agricultural Experiment Station




APPENDIX

TABLE 1.-CHMICAL COMPOSITION OF THE FEEDS USED IN THE DOUBLE-REVERSAL
FEEDING TRIALS.

Composition of the Dry Matter



4)5

7:1 b a


0 F US M U


Alfalfa hay 8.92
7.67
7.80
6.92
7.02
8.45
8.60
9.50
3.73

Corn feed meal 11.89
9.12
11.55

Corn silage, 71.54
prolific type 65.69
65.17
76.16
64.98
63.44
55.82
63.66

Cottonseed 8.99
meal 8.66

C. intermedia 76.93
silage 74.56
69.54
79.79
80.67
79.53
73.17
67.33
76.76

Wheat bran 11.05
12.42


17.53 2.00 31.70 38.77
15.67 1.78 31.22 43.32
16.67 2.06 27.20 43.58
16.01 3.08 29.79 42.66
16.30 2.77 29.33 43.33
13.98 2.41 35.16 41.93
15.57 3.03 29.62 43.55
15.25 2.87 27.64 45.65
16.44 2.73 29.12 43.43

10.71 3.90 2.48 80.94
12.40 9.10 5.12 69.58
11.64 5.10 2.09 79.64

7.11 2.62 27.66 57.13
6.74 2.88 24.99 60.81
6.39 2.35 25.35 60.84
7.17 2.93 26.49 59.32
6.46 3.05 24.72 61.34
8.30 2.97 20.57 62.17
7.86 3.14 19.01 66.02
7.89 2.79 22.28 61.95

43.10 5.99 14.75 29.64
44.57 8.21 10.88 29.34

8.14 1.72 50.06 22.93
10.14 2.33 24.36 58.64
13.75 3.02 48.77 30.54
12.22 3.02 43.85 33.15
11.27 2.57 51.20 29.36
12.96 3.38 45.36 31.51
13.61 2.90 41.35 37.01
15.65 3.01 37.21 38.32
12.14 2.86 44.13 36.19

20.42 4.43 10.37 57.72
18.20 3.46 11.78 59.25


10.00 1.529 .205 .262
8.01 1.289 .134 .284
10.49 1.540 .176 .282
8.46 1.034 .225 .177
8.27 1.038 .220 .141
6.52 .838 .150 .148
8.23 1.712 .277 .230
8.50 1.712 .318 .177
8.28 1.696 .225 .276

1.97 .050 .152 .228
3.71 .011 .342 .328
1.53 .018 .136 .353

5.48 .244 .147 .332
4.58 .232 .191 .422
5.07 .248 .195 .306
4.09 .340 .180 .247
4.43 .319 .186 .169
5.99 .112 .193 .271
3.97 .125 .172 .264
5.09 .206 .214 .301

6.43 .231 .476 1.320
7.00 .209 .424 1.162

17.15 .620 .178 .251
4.53 .583 .197 .279
3.92 .685 .215 .259
7.76 .940 .379 .332
5.60 .711 .376 .299
6.79 .834 .364 .242
5.13 .754 .362 .270
5.81 .828 .440 .253
4.68 .768 .424 .196

7.06 .127 .211 .363
7.31 .094 .434 .967




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