Productivity of Columbia sheep in Florida and their use for crossing with native sheep

Material Information

Productivity of Columbia sheep in Florida and their use for crossing with native sheep
Series Title:
Bulletin University of Florida. Agricultural Experiment Station
Whitehurst, V. E.
Place of Publication:
Gainesville Fla
University of Florida Agricultural Experiment Station
Publication Date:
Physical Description:
34 p. : ill. ; 23 cm.


Subjects / Keywords:
Sheep -- Breeding -- Florida ( lcsh )
bibliography ( marcgt )
non-fiction ( marcgt )


Bibliography: p. 33-34.
General Note:
Cover title.
General Note:
"In cooperation with U.S. Department of Agriculture"--T.p.
Bulletin (University of Florida. Agricultural Experiment Station)
Statement of Responsibility:
by V. E. Whitehurst ... <et al.>.

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Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
027123094 ( ALEPH )
18253532 ( OCLC )
AEN6153 ( NOTIS )


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Full Text

February, 1947

(In Cooperation with U. S. Department of Agriculture)








Single copies free to Florida residents upon request to

Bulletin 429


J. Thos. Gurney, Chairman, Orlando
N. B. Jordan, Quincy
Thos. W. Bryant, Lakeland
M. L. Mershon, Miami
J. Henson Markham. Jacksonville
J. T. Diamond, Secretary, Tallahassee


John J. Tigert, M.A., LL.D., President of the
H. Harold Hume, D.Sc., Provost for Agricul-
Harold Mowry, M.S.A., Director
L. O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield, M.S., Asst. Dir., Admin.
J. Francis Cooper, M.S.A., Editors
Clyde Beale, A.B.J., Associate Editor3
Jefferson Thomas, Assistant Editors
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager'
K. H. Graham, LL.D., Business Managers
Claranelle Alderman, Accountants



W. E. Stokes, M.S., Agronomist'
Fred H. Hull, Ph.D., Agronomist
G. E. Ritchey, M.S., Agronomists
G. B. Killinger, Ph.D., Agronomist
W. A. Carver, Ph.D., Associate
H. C. Harris, Ph.D., Associate
Fred A. Clark, B.S., Assistant


A. L. Shealy, D.V.M., An. Industrialist1
R. B. Becker, Ph.D., Dairy Husbandmans
E. L. Fouts, Ph.D., Dairy Technologists
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarians
L E. Swanson, D.V.M., Parasitologist
N. R. Mehrhof, M.Agr., Poultry Hush.8
G. K. Davis, Ph.D., Animal Nutritionist
R. S. Glasscock, Ph.D., An. Husbandman
P. T. Dix Arnold, M.S.A., Asst. Dairy Husb.'
C. L. Comar, Ph.D., Asso. Biochemist
L. E. Mull, M.S., Asst. in Dairy Tech.
Katherine Boney, B.S., Asst. Chem.
J. C. Driggers, B.S.A., Asst. Poultry Hush.
Glenn Van Ness, D.V.M., Asso. Poultry
John S. Folks, B.S.A., Asst. An. Husb.


C. V. Noble, Ph.D., Agri. Economist' s
Zach Savage, M.S.A., Associates
A. H. Spurlock, M.S.A., Associate
D. E. Alleger, M.S., Associate
D. L. Brooke, M.S.A., Associate

Orlando, Florida (Cooperative USDA)

G. Norman Rose, B.S., Asso. Agr. Economist
J. C. Townsend, Jr., B.S.A., Agr. Statistician'
J. B. Owens, B.S.A., Agr. Statistician'


Ouida D. Abbott, Ph.D., Home Econ.'
R. B. French, Ph.D., Biochemist


A. N. Tissot, Ph.D., Entomologist and Act-
ing Head of Dept.
H. E. Bratley, M.S.A., Assistant


G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Asso. Horticulturist
F. S. Jamison, Ph.D., Truck Hort.
Byron E. Janes, Ph.D., Asso. Hort.
R. A. Dennison, Ph.D., Asso. Hort.
R. K. Showalter, M.S., Asso. Hort.
R. J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Hort.
Victor F. Nettles, M.S.A., Asst. Hort.
F. S. Lagasse, Ph.D., Asso. Hort.2


W. B. Tisdale, Ph.D., Plant Pathologist'
Phares Decker, Ph.D., Asso. Plant Path.
Erdman West, M.S., Mycologist and Botanist
Lillian E. Arnold, M.S., Asst. Botanist


F. B. Smith, Ph.D., Chemist' s
Gaylord M. Volk, Ph.D., Chemist
J. R. Henderson, M.S.A., Soil Technologist
J. R. Neller, Ph.D.,' Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
C. E. Bell, Ph.D., Associate Chemist
L. H. Rogers, Ph.D., Associate Biochemist
R. A. Carrigan, B.S., Asso. Biochemist
H. W. Winsor, B.S.A., Assistant Chemist
Geo. D. Thornton, M.S., Asst. Microbiologist"
R. E. Caldwell, M.S.A., Asst. Soil Surveyor
Wade McCall, B.S., Asst. Chemist
J. B. Cromartie, B.S.A., Asst. Soil Surveyor

1 Head of Department.
2 In cooperation with U. S. D. A.
3 Cooperative, other divisions, U. of F.
SIn Military Service.
6 On leave.



J. D. Warner, M.S., Vice-Director in Charge
R. R. Kincaid, Ph.D., Plant Pathologist
W. H. Chapman, M.S., Asso. Agron.
R. C. Bond, M.S.A., Asso. Agronomist
L. G. Thompson, Ph.D., Soils Chemist
Frank D. Baker, Jr., B.S., Asst. An. Hush.

Mobile Unit, Monticello

R. W. Wallace, B.S., Associate Agronomist

Mobile Unit, Marianna

R. W. Lipscomb, M.S., Associate Agronomist

Mobile Unit, Wewahitchka
J. B. White, B.S.A., Associate Agronomist


A. F. Camp, Ph.D., Vice-Director in Charge
V. C. Jamison, Ph.D., Soils Chemist
W. L. Thompson, B.S., Entomologist
J. T. Griffiths, Ph.D., Entomologist
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, M.S., Plant Pathologist6
J. E. Benedict, B.S., Horticulturist
B. R. Fudge, Ph.D., Associate Chemist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
James K. Colehour, M.S., Research Chemist
T. W. Young, Ph.D., Asso. Horticulturist
J. Sites, M.S.A., Asso. Horticulturist
H. 0. Sterling, B.S., Asst. Horticulturist
J. A. Granger B.S.A., Asst. Horticulturist
H. J. Reitz, M.S., Asso. Plant Path.
Francine Fisher, M.S., Asso. P1. Path.


R. V. Allison, Ph.D., Vice-Director in Charge
J. W. Wilson, Sc.D., Entomologist
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph.D., Sugarcane
B. S. Clayton, B.S.C.E., Drainage Eng.'
W. D. Wylie, Ph.D., Entomologist
W. T. Forsee, Jr., Ph.D., Asso. Chemist
R. W. Kidder, M.S., Asst. An. Husb.
T. C. Erwin, Assistant Chemist
R. A. Bair, Ph.D., Asst. Agronomist
C. C. Scale, Asst. Agronomist
L. O. Payne, B.S.A., Asst. Agronomist
Russel Desrosiers, M.S., Asst. Plant Path.
N. C. Hayslip, B.S.A., Asst. Hort.


Geo. D. Ruehle, Ph.D., Vice-Director in
H. I. Borders, M.S., Asso. Plant Path.6
D. O. Wolfenbarger, Ph.D., Asso. Ento.
R. W. Harkness, Ph.D., Aist. Chemist


Clement D. Gorden, Ph.D., Poultry Geneticist
in Charge2


W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Associate Agronomist
D. W. Jones, B.S.A., Asst. An. Hush.
E. R. Felton, B.S.A., Asst. An. Hush.

R. W. Ruprecht, Ph.D., Chemist in Charge
A. Alfred Foster, Ph.D., Asso. Hort.
J. C. Russell, M.S., Asst. Entomologist
Ben F. Whitner, Jr., B.S., Asst. Hort.

H. W. Lundy, B.S.A., Asst. Agronomist

G. K. Parris, Ph.D.. Plant Path. in Charge

Plant City
A. N. Brooks, Ph.D., Plant Pathologist

A. H. Eddins, Ph.D., Plant Pathologist
E. N. McCubbin, Ph.D., Truck Horticulturist

S. O. Hill, B.S., Asst. Entomologist' '
A. M. Phillips, B.S., Asst. Entomologist'


J. R. Beckenbach, Ph.D., Horticulturist in
E. G. Kelsheimer, Ph.D., Entomologist
David G. Kelbert, Asso. Horticulturist
E. L. Spencer, Ph.D., Soils Chemist
Robert O. Magie, Ph.D., Hort., Glad. Inv.
Donald S. Burgis, M.S.A., Asst. Hort.

Warren O. Johnson, Meteorologist'

1 Head of Department.
2 In cooperation with U. S.
Cooperative, other divisions, U. of F.
In Military Service.
SOn leave.



INTRODUCTION .........- ................................................... 5

METHOD OF MANAGEMENT ............................................. ..................-- 6

M anagem ent at Dubois, Idaho ...................................... ........................ 6

M management at Quincy, Florida ................................. ......................... 8

DESCRIPTION OF DATA COLLECTED ................... ........... .......................... 13

MATERIAL, DATA AND DISCUSSION ........................ ........ .......... .......... 14

Comparison of Columbia Sheep in Idaho and Florida ........................ 14

Comparison of Columbia, Native, and Grade Sheep in Florida........... 21

Discussion of Results ........................-...........- --- .................... 29

SUM MARY ---- --.................... .................................. ................. 32

LITERATURE CITED ....-.............--.......- ------------................. .............. 33



Columbia sheep were developed by the Bureau of Animal In-
dustry at the United States Sheep Experim/nt Station, Dubois,
Idaho. The procedure, described by Spencer and Stoehr (12),5
was to cross Lincoln rams and Rambouillet ewes, and to proceed
from this original cross by mating the most select first-cross
rams with carefully selected first-cross ewes and interbreeding
the rams and ewes descending from them.
The Columbia breed was developed under strictly range condi-
tions (Fig. 1), and sheep of this breed have proved well adapted
to production of wool and mutton under those conditions. The
object of the work described in this bulletin was to test their
adaptability to a quite different set of environmental conditions,
at the North Florida Experiment Station, Quincy, Florida (Fig.
2). The work was divided into 2 phases. In the first phase,
2 comparable groups of Columbia ewes were selected. One was
retained at Dubois, Idaho (Fig. 4) and the second was placed
at Quincy, Florida (Figs. 3, 5), and their productivity was
studied under the 2 sets of environmental conditions. In i the
second phase, Columbia rams were mated to both Columbia and

1This work was conducted cooperatively by the Florida Agricultural
Experiment Station and the Bureau of Animal Industry, Agricultural Re-
search Administration, U. S. D. A.
2 Formerly Assistant Animal Husbandman, Florida Agricultural Experi-
ment Station.
SSenior Animal Husbandman, Bureau of Animal Industry, U. S. D. A.
'There were many changes in personnel during the activity of the
project. L. O. Gratz, now Assistant Director, Research, Florida Agricul-
tural Experiment Stations, was in charge of the North Florida Station,
Quincy, Florida, when the project was begun and for several years during
its operation. Acknowledgment is made of his efforts in directing this
project at that Station during this time. Other persons who contributed
to the work at Quincy were Bradford Knapp, Jr., formerly stationed at
Gainesville, Florida, by the Bureau of Animal Industry as Assistant Animal
Husbandman, W. W. Henley, formerly Assistant Animal Husbandman,
Florida Agricultural Experiment Station, A. L. Shealy, Animal Industrialist
and Head, Animal Industry Department, Florida Agricultural Experiment
Station, and J. D. Warner, now in charge of the North Florida Station.
Workers in the Bureau of Animal Industry who also contributed to certain
phases of the work include John M. Cooper, John A. Stoehr, John I. Hardy
and Ralph G. Schott.
SItalic figures in parentheses refer to literature cited.

Florida Agricultural Experiment Station

native ewes (Figs. 3, 6) that had been raised in Florida. F1
rams and ewes from the use of Columbia rams on native ewes
were interbred to produce an F2 generation. Hence, there were
available for comparisons Columbia, native, F1 and F2 ewes, all
of which had been raised in Florida (Fig. 7).
The origin of the native Florida sheep is unknown. They are
small in size and yield a small wool clip. Factors contributing
to their smallness in size are (1) lack of high quality feed, (2)
internal parasites, (3) lack of selective breeding and (4) pos-
sibly inbreeding.

The method of managing the sheep was the same in both
phases of the experimental work at Quincy. The method at
Dubois applies only to the Columbia ewes that were retained
there in connection with the first phase of the work. Methods
of management at the 2 places are outlined below.

The ewes and lambs of the Columbia flock at the United States
Sheep Experiment Station, Dubois, Idaho, were grazed on range
of the sagebrush type near Dubois during the spring and fall
(Fig. 1). While the sheep were on this range, all water required
had to be hauled in tanks from headquarters to movable troughs.
The forage in the spring consisted mainly of green grasses, al-
though wild onions were eaten when available and balsani fur-
nished some feed during the early stages of growth. In the
fall the range grasses were field-cured and dry, and a consider-
able amount of the forage consumed by sheep consisted of sage-
brush and bitterbrush. After shearing and dipping in the spring,
the ewes and lambs were trailed to summer range, of which the
Station has 2 types. That located on the Targhee National Forest
about 20 miles north of headquarters furnishes about /4 grass
and 4 "weed" feed 6 and dries rapidly about the latter part of
July. The summer range at a higher level located about 40 miles
northeast of headquarters on the north slope of the Continental
SThe term "weeds" as used here refers to those flowering plants which
are of great economic value for forage on western ranges, but might be
termed as noxious in cultivated areas.

Fig. 1.-Above: View of summer range upon which Columbia sheep
were grazed at Dubois, Idaho; below: view of spring-fall sagebrush range
near Dubois.



~L r~ :~CL~L~ lilL
T -~-

.Florida Agricultural Experiment Station

Divide furnishes about % "weed" and 14 grass feed. Green
succulent feed was available on this range until killing frosts
in September.
After leaving the fall range (sagebrush type near Dubois)
about the first part of December, the breeding ewes were grazed
on winter range located about 35 miles southwest in the Salmon
National Forest. When snow became too deep for practical graz-
ing, the ewes were moved to the feed lots in the irrigated valleys
where alfalfa hay was available. In the spring for about 2
weeks to a month before lambing the ewes received from 1/4 to
1/2 pound of cottonseed cake per head daily. Lambing operations
were carried on at or near station headquarters during April
and May. Lambing sheds were used. Ewes received grain,
usually whole oats, in addition to alfalfa hay after lambing and
until they were turned on grass.
The sheep of this project at Quincy, Florida, were pastured,
fed and cared for by methods that might apply to farm condi-
tions in the area. As the object of this undertaking was to
determine the possibility of improving efficiency of native Flor-
ida sheep for the production of high quality wool and mutton,
and the development of an improved strain that will breed true
to a type suitable to the economic requirements of sheep pro-
ducers in northern Florida and similar territory, the experi-
mental variables were all confined to sheep breeding research.
The pasturing and feeding practiced were intended to be good
practical methods of keeping the sheep healthy and strong and
adequate for the production of good wool and lambs in the
abundance commensurate with the costs of such maintenance.
Pasture was used extensively as the source of feed for the
sheep and lambs, but to keep these animals thrifty and strong
under the environment for sheep at Quincy they were fed some
hay and grain, especially in times when the forages of the
pastures were relatively low in quantity and quality.
The sheep were'moved from pasture to pasture rather frequent-
ly so as to hold the forage in production of palatable, nutritious
grazing. For the first few years of this experiment the sheep were
grazed on carpet grass, wire grass and several other native
grasses. In later years it was found that this practice did not

Fig. 2.-Above: view of sheep pastures at Quincy, Florida; below: shelter
provided for sheep at Quincy.





Florida Agricultural Experiment Station

provide adequate grazing and was conducive to internal parasite
infestation; therefore, a system of temporary grazing crops was
initiated that provided nutritious grazing for about 11 months
in the year. This system included such crops as oats, soybeans,
cowpeas, pearl millet and various varieties of clovers.
From December until June oats provided much of the grazing
and from March to June the major portion of the grain.
Hay fed to these sheep and lambs was made from cowpeas,
soybeans and oats. The daily allowance ,of these hays, along
with other feeds, was usually about 2 pounds per breeding ewe,
although this varied from about 1/2 pound to 3 pounds, depend-
ing on the needs for hay as the source of roughage and on its
quality and palatability.
A sincere effort was made to provide the feeds essential for
the growth of the lambs and they- were fed in creeps so that
their big, strong mothers could not disturb them or eat the feed
intended for them. Some of the small native ewes were so
nearly the same size of the larger lambs that they could, and
did, enter the lamb creeps and eat with the lambs, but such was
not the rule and in general the lambs were well fed.
Grain was fed to the ewes at lambing time and during the
nursing period when adequate grazing was not available. The
daily allowance of such concentrates varied from 1/4 pound to
2 pounds per head, depending on the need for grain. The usual
allowance was about 1 to 11/2 pounds per ewe daily. The grains
were mixed in various proportions in accordance with the need
and the availability. The following mixtures in parts by weight
are typical of the combinations used.

(1) Corn 300, oats 200, cottonseed meal 100.
(2) Corn 400, oats 400, cottonseed meal 100.
(3) Oats 920, cottonseed meal 50, bone meal 30.
(4) Ground corn and oats equal parts 870, cottonseed meal
30, bone meal 100.
(5) Corn 140, oats 67, cottonseed meal 23, bone meal 7.
(6) Ground snapped corn 100, ground oats 100, cottonseed
meal 23, bone meal 7.
(7) Ground snapped corn 500, ground oats 200, cottonseed
meal 100, bone meal 20.

Fig. 3.-Above: A portion of Columbia ewes that were transferred from
Dubois to Quincy; below: group of native ewes used in the work at Quincy.

P 001

T I,-add


Florida Agricultural Experiment Station

,(8) Ground snapped corn 350, oats 350, cottonseed meal 100,
bone meal 10.
(9) Ground snapped corn 600 and cottonseed meal 100.
(10) Ground oats 400 and peanut meal 100.
(11) Ground snapped corn 500 and soybean meal 100.
(12) Straight peanut meal.
The rams were kept in pens and pastures by themselves ex-
cept at breeding time, when they were running with the ewes.
Only 1 ram was allowed with each pen of ewes so that his lambs
could be, and were, identified and eartagged individually as his
offspring at lambing time.
The pastures and corrals for the sheep were well fenced so
as to keep the sheep securely in their respective enclosures and
to protect them from sheep-killing dogs. These fences were
sufficiently strong to control the big, husky rams, and accidental
or unknown matings were well prevented.
The sheep were adequately provided with salt and had access
to good water at all times. The laborers charged with the actual
care of these sheep took genuine interest in them. The sheep
and even the suckling lambs gave evidence of knowing their
shepherds, and the confidence which these sheep had in their
caretakers was very noticeable.
Owing to the fact that this work was conducted in a place
where temperatures are relatively high during much of the
year, an effort was made to breed ewes at such a time that
lambs would be born during the cool winter months. Consider-
able success attended this effort, as may be seen from the follow-
ing tabulation of the numbers of lambs born in each month:
January ......................335 July .............................- 0
February .........-- .... .. 32 August ...................-... 3
M arch .......................... 9 September .................. 0
April ............................ 5 October ....................... 27
M ay ............................. 0 November ................. 31
June ............................ 2 December .............-......127
This record shows that 97 percent of the lambs were born
from October through February so that their breeding season
had to be during Florida's warm weather, from May through
September, when it is relatively difficult to get ewes to conceive
in central and northern portions of the United States. These
data indicate that the normal breeding season of sheep may not
be so restricted in the southern portion of the country as it is
farther north, but more critical experimental evidence is needed
on this point.

Columbia Sheep Productivity in Florida

The data used in the analyses reported in this bulletin were
essentially the same in both phases of the work. They are de-
scribed briefly below.
Body weights were taken on all ewes used in the studies, at
birth, weaning, and at yearly intervals from 1 to 7 years of age.
Birth weights were taken as soon as was feasible after lambs
were born. Weaning weights were taken at about 5 months,
and were adjusted to a standard age of 140 days, using the
method developed by Phillips and Brier (7). Yearling weights
were taken at shearing time when the ewes were approximately
1 year old. Weights at later ages were taken at or near the
beginning of the breeding season. At Quincy the weights used
were taken on or near August 1, since most of the ewes conceived
there during July and August. At Dubois these weights were
taken in November.
Fleece weights and lengths were obtained at shearing time
in the spring. Those on yearlings were adjusted to 3.65 days of
growth. In some cases at Quincy lambs born in the fall or early
winter were shorn as lambs in the following spring. In these
cases fleece weights and lengths were added to those obtained
1 year later when these sheep were somewhat over 1 year old,
and the total figures were adjusted to 365 days' growth of fleece.
Fleece weights and lengths at 2 years and later ages represented
approximately 365 days' growth, hence no adjustments were
The proportion of ewes lambing is expressed as -the percent
of those ewes present in the flock at shearing time in the spring
that produced lambs.
Number of lambs produced by each ewe was recorded at birth
and the data given in this bulletin represent the average number
per ewe in each group of animals. The data are reported in the
tables on the basis of the number of lambs per ewe that actually
The significance of differences between various groups in the
proportion of ewes that lambed was determined by the use of the
chi-square test. Differences in all the other characteristics
were tested by the method of determining significance of differ-
ences between means described by Snedecor (11), Fisher (1)
and others.

14 Florida Agricultural Experiment Station

In the summer of 1933 60 mature ewes of the Columbia breed
were selected from the Bureau of Animal Industry's flock at
the United States Sheep Experiment Station, Dubois, Idaho.
The ewes were divided into 2 lots of 30 each, 1 to be retained at
Dubois and 1 to be sent to the North Florida Experiment Station
at Quincy. Each lot was composed of 5 5-year-old ewes, 5 4-year-
olds, 10 3-year-olds, and 10 2-year-olds. The 2 lots were made
as nearly equal as possible in wool and mutton scores and pro-
duction records. Selections were made in such a manner as to
obtain 30 pair mates. One ram each of 2 pairs of rams, ap-
proximately equal in individuality, production and breeding, was
retained to mate with the ewes at Dubois and the other member

Fig. 4.-Typical Columbia ewes in the experiment at Dubois.. Ages: upper
left, 5 years; upper right, 4 years; lower left, 3 years; lower right, 2 years.

Columbid Sheep Productivity in Florida

of each pair was sent to Quincy. Every effort was made to
eliminate all variable factors except the environmental differ-
ences existing between the Northwestern range region and the
Southeastern pasture region.
Six of the Dubois ewes died of poison in the fall of 1933.
Two of these were replaced, so only 26 ewes actually started in
the Dubois phase of the experiment. One of the Florida ewes
died at about the same time, leaving 29 to start the experiment.
A considerable loss was suffered at Quincy in the following year
when, in the fall of 1934, 9 ewes died as a result of parasites
and treatments to control parasites, and 2 others died prior to
the 1935 lambing season.
Owing to differences in productivity of ewes at various ages,
comparisons were made within age groups. The numbers of
ewes available and the number of offspring produced at each
age are shown in Table 1. All of these animals were at Dubois
until they were 2 years old or over, hence the numbers involved
and the data presented in Tables 2 and 3 prior to 3 years of age
are included to show the relative merits of the 2 groups of ani-
mals at comparable ages before they were selected for use in
this experiment. The average data on the individual ewes in
each group are shown in Table 2, and differences between these
averages are shown in Table 3.
The-data in Table 3 show that the group of ewes sent to
Quincy did not differ significantly from those remaining at Du-
bois in body weight, fleece weight, fleece length, or lamb pro-
duction at 2 years of age. The only large difference was in
weight at 1 year of age. This was not statistically significant.
The differences recorded in Table 3 for ages of 3 to 7 years
are the critical data upon which comparisons of the reactions
of Columbia sheep to the 2 environments can be based, since
only those data are included which were obtained after the
experiment started in 1933. At 2 ages the ewes at Dubois were
significantly heavier while at 2 other ages non-significant differ-
ences were in favor of the ewes at Quincy; thus, there is some
indication that the ewes stayed in better condition at Dubois.
The fleeces of the ewes at Dubois were slightly heavier and
longer at 3 ages, while those at Quincy were heavier and longer
at 2 ages. The differences were non-significant, except for weight
of fleece at 7 years. These data indicate that fleece production
was about equally satisfactory at the 2 stations.
A higher proportion of the ewes retained at Dubois lambed


Numbers of Animals in Study, Grouped According to Age of Ewes
LocationBirth Weaning 1 Year 2 Years 3 Years 4 Years | 5 Years 1 6 Years 1 7 Years

Number of Ewes

* Dubois, Idaho ............. 26 26 26 26 8 (9)* 13 (14) 14 (17) 12 (19)

Quincy, Florida ....... 29 29 :8 29 8 (10) 16 (17) 16 (17) 14 (16)

Number of Offspring

Dubois, Idaho ............ .... .. -.- 18 11 13 22 20

Quincy, Florida ...... ... .. ---.... 26 4 9 15 16

Numbers in parentheses indicate sheep upon which fleece data were obtained, in cases where these numbers differed from the num
available when weights were taken.




ber of sheep


Data on Size and Productivity, Grouped According to Age of Ewes
Group I
SBirth Weaning 1 Year I 2 Years I 3 Years | 4 Years 5 Years 6 Years 1 7 Years
Body Weight (pounds)
Dubois .................... 9.78 75.65 78.31 138.42 125.62 144.00 145.43 140.92
Quincy .................... 9.71 78.76 92.25 135.07 129.50 130.19 127.94 145.64 161.33
Weight of Fleece (pounds)
Dubois ............... ... .. .... 10.22 11.59 11.89 12.75 11.98 11.70 10.81
Quincy ...... .... ... .. .... 10.79 11.80 10.88 12.57 12.55 11.60 13.81
Length of Fleece (centimeters)
Dubois ....................... .. ..... 8.38 9.04 8.97 8.70 8.91 8.60 8.06
Quincy ........................ .... 8.59 9.49 8.04 8.52 8.93 8.12 8.16
Precent of Ewes Lambing
Dubois ........................ -. 84.6 100.0 64.3 88.2 84.2 100.0
Quincy ......... ............ ........ 89.7 30.0 47.0 82.4 93.8 77.8
Number of Lambs Born per Ewe that Lambed
Dubois .......... ......... ............ 1.06 1.22 1.44 1.47 1.25 1.50
Quincy ....................... .... .. 1.08 1.33 1.25 1.14 1.13 1.00
Birth Weight of Lambs (pounds)
Dubois ....................... .. ... 9.14 9.16 9.77 10.20 9.86 10.02
Quincy .......................... ... | ........ 9.34 9.00 9.39 8.28 8.09 8.08
Weaning Weight of Lambs (pounds)
Dubois ................................ .... 72.57 73.70 90.62 85.35 83.90 83.62 .
Quincy ................... .... .......- .... 73.95 72.00 49.67 57.50 65.93 78.40


Differences in Size and Productivity, Grouped According to Age of Ewes
Groups Compared 1
S Cmae Birth | Weaning I 1 Year 1 2 Years | 3 Years | 4 Years 5 Years 6 Years 7 Years
Body Weight (pounds)
Dubois-Quincy ............ .07 -3.11 -13.94 3.35 1 -3.88 13.81* 17.49** -4.72 .-
Weight of Fleece (pounds) o
Dubois-Quincy ..-.....-... .. .... -.57 -.21 1.01 I .18 -.57 .10 --3.00**
Length of Fleece (centimeters)
Dubois-Quincy .......... .... .... -.21 | -.45 .93 .18 -.02 .48 -.10
Percent of Ewes Lambing
Dubois-Quincy ........-. ..... .. -5.1 70.0 I 17.3 5.8 -9.6 22.2
Number of Lambs Born per Ewe that Lambed
Dubois-Quincy ......... ... ... I .... -.02 -.11 .19 .33* .12 .50**
Birth Weight of Lambs (pounds) __
Dubois-Quincy ....-... ..... ... -.20 .16 ] .38 1.92** 1.77** 1.94* 'c
Weaning Weight of Lambs' (pounds) 0
Dubois-Quincy ........... ... .... I ... -1.38 1.70 40.95** 1 27.85** 1 17.97* 5.22
1 When difference is in favor ofthe Quincy group, a minus sign is used. Otherwise, the difference is in favor of the Dubois group.
P =.05 or less. ** P = .01 or less.

Columbia Sheep Productivity in Florida

at 3, 4, 5 and 7 years of age than of those sent to Quincy. Differ-
ences are not statistically significant with the numbers involved,
but there is an indication that the ewes at Quincy required about
2 years to adjust to the new environment before they could
reproduce normally. This point may be brought out more clearly
by considering the 2 groups as a whole, without regard to age.
In the first year after the experiment was initiated, 22 of the
26 ewes at Dubois produced live lambs while only 16 of the 29
at Quincy had live lambs. In the second year, 20 of the 24
remaining ewes at Dubois produced live lambs while only 7 out
of 18 ewes at Quincy produced live lambs.
In the production of the second lamb crop at Quincy 1 of the
Columbia rams, 1895-K, was very ill with parasite infestation.
He was then mated with 24 ewes and sired only 6 lambs. The
Fig. 5.-Typical Columbia ewes raised at Dubois and transferred to
Quincy. Ages: upper left, 5 years; upper right, 4 years; lower left, 3 years;
lower right, 2 years.

I -

Florida Agricultural Experiment Station

other Columbia ram, 1882-K, used that year was apparently in
good health and he, being mated with 25 ewes, sired 19 lambs.
In the production of the third crop of lambs these same 2 Colum-
bia rams were used when from treatment for internal parasites
and with good feed and care they were both in good health.
Ram 1895-K was mated with 25 ewes and sired 18 lambs and
1882-K was mated with 24 ewes and sired 18 lambs. Thus it
appears that effective parasite control definitely favored lamb
By the third year of the experiment the ewes at Quincy ap-
peared to be adapted to their new environment with respect to
breeding, since 13 of the 15 remaining ewes had live lambs, as
compared with 10 out of 12 ewes with live lambs at Dubois.
The reason for the slow process of adaptation to a new en-
vironment, as measured by reproduction, is not clear. The
shift in latitude may have affected the ovarian rhythm. Such
shifts have been observed to affect ovarian rhythm in sheep
when transported from the northern to the southern hemisphere
(4). Critical data are not available on the effects on reproduc-
tion of moving ewes from one latitude to another within the same
hemisphere, but some data (10) on sheep of similar breeding,
maintained at Beltsville, Maryland, and Middlebury, Vermont,
indicate that those at Middlebury tended to have a longer breed-
ing season. Another factor may have been the reaction of the
rams to the warmer climate at Quincy. The works of Phillips
and McKenzie (8), McKenzie and Berliner (5), Green (2), Gunn,
Sanders and Granger (3), and Phillips et al (9) have shown that
high temperatures often reduce the quality of semen produced
by rams, thereby lowering fertility and in some cases causing
temporary sterility. Still another factor that seems to have
contributed to the low reproductive rate at Quincy was the heavy
infestation with parasites of the pastures upon which the sheep
were grazed. A change in management of the sheep after the
first 2 seasons reduced the damage from parasites and the im-
proved conditions appear to have been at least partially respons-
ible for the improved reproductive rate at that time.
In number of lambs born per ewe that lambed the ewes at
Dubois excelled in 4 of the 6 age groups (see Table 3), and the
difference in their favor was significant in 2 cases. Thus, it
appears that Columbia sheep were able to maintain a somewhat
higher level of reproduction at Dubois than at Quincy.
Lambs produced by ewes at Dubois were heavier at birth than

Columbia Sheep Productivity in Florida

those at Quincy in all age groups (3 years and above) and the
differences were significant in 3 of the 5 age groups. They were
also heavier in all cases at weaning and here also the differences
were significant in 3 out of 5 age groups. In these 3 groups,
when ewes were 4, 5 and 6 years of age, the respective average
differences were 40.95, 27.85 and 17.97 pounds.
In this phase of the work the Columbia sheep used were
descendants of those brought from Dubois for use in the first
phase of this work, described above. Native sheep typical of
those found in the section around Quincy were purchased (Figs.
3, 6). The ages of most of these were unknown and some were
pregnant when purchased. Data were obtained on the descend-
ants of these purchased native ewes and only those native ani-
mals of known age were included in the present analysis. The
F1 ewes resulted from mating Columbia rams to native ewes;
the F2 ewes were produced by inter se matings, using Fi rams
and ewes (Fig. 7).
The numbers of ewes of each of the types of breeding used
in this study are listed in Table 4, along with the numbers of
offspring upon which data were obtained. The offspring listed
in the lower half of Table 4 were not all of the same breeding
as the ewes, since various types of rams were used and successive
generations were involved. The breeding of the offspring is
indicated below.
The offspring of Columbia ewes were all sired by Columbia
rams, with the exception of 1 lamb in the 2-year-old and 1 in
the 3-year-old group, whose sires were unknown.
The majority of the offspring of native ewes were sired by
Columbia rams. The remaining lambs were sired by native
rams and the numbers in this category in the various age groups
were: 2-year-old, 1 lamb; 3-year-old, 3 lambs; 4-year-old, 2
lambs; 6-year-old, 2 lambs.
The majority of the lambs from Fi ewes were sired by F1
rams. The remaining lambs were produced by backcrossing to
Columbia rams, and the numbers in this category in the various
age groups were: 2-year-old, 4 lambs; 3-year-old, 14 lambs;
4-year-old, 16 lambs; 5-year-old, 17 lambs; 6-year-old, 18 lambs;
7-year-old, 5 lambs.
Only a small portion of the lambs out of F2 ewes were sired
by F2 rams. These included 12 from the 2-year-old ewes, 3


SNumbers of Animals in Study, G.ouped According to Age of Ewes
Breeding of Ewes
Birth I Weaning | 1 Year | 2 Years 1 3 Years I 4 Years | 5 Years I 6 Years I 7 Years
Number of Ewes

Columbia .................... 38 38 29 24 20 13 (15) 12 (13) 9 6 (9)
Native --. ........ 25 25 25 20 (21)* 17 (20) 11 (15) 3 (7) ... (3) ...
F, ........... .......... ....... 71 71 71 60 (66) 52 (54) 39 27 (29) 13 (15) 2 (3)
Fz ............................ 55 55 48 32 (39) 21 (23) 7 (10) 1 ...

Number of Offspring

Columbia ...................... ........ .... 10 10 10 9 7 8
N ative ......... ......... .... .... ... 15 13 14 6 5
F1 .................................. .... ....... 50 55 56 42 24 5
F2 ....................... ..... ... ........ 32 24 14 1

Numbers in parentheses indicate sheep upon which fleece data were obtained, in cases where these numbers differed from the number of sheep
available when weights were taken.

Columbia Sheep Productivity in Florida 23

from the 3-year-olds, and 1 from the 4-year-olds. The remain-
ing lambs were sired by Columbia rams.
Data on body weight and fleece production are presented in
Table 5 and data on lamb production are presented in Table 6.
Differences between the averages of the various groups are pre-
sented in Tables 7 and 8.
Columbia ewes were heavier and produced heavier fleeces of
longer staple than the native ewes at all ages in which compari-
sons were made (see Table 7) with the exception of length of
fleece at 1 year, when the small non-significant difference was
in favor of the native ewes.
Columbia ewes were significantly lighter than F1 ewes at
birth and were significantly heavier at 2 years of age, but at all
other ages differences were non-significant and were in favor of

Fig. 6.-Typical native ewes in the experiment at Quincy. These ewes
were purchased and their ages were not known.


Data on Size and Fleeces, Grouped According to Age of Ewes

Breeding of Ewes I
I Birth I Weaning 1 Year I 2 Years I 3 Years | 4 Years | 5 Years 6 Years 1 7 Years

Colum bia ............... ....
N ative ......................
F1 ................................
F2 ..................................

Colum bia ....................-
N ative .. ...............
F, .................................
F ................ ..... ....-

Body Weight (pounds)

7.33 62.10 90.7 134.88 146.50 155.23 140.08 145.11 145.67
7.28 48.16 67.08 91.15 98.35 103.54 109.00
8.02 60.17 92.20 120.32 141.10 146.68 145.41 147.77 163.00
8.14 71.42 107.65 152.69 162.52 159.86 125.00

Weight of Fleece (pounds)

10.32 12.70 12.74 13.45 11.25 12.81 10.26
4.90 5.05 5.76 5.30 4.96 4.90
8.86 9.90 9.44 9.02 8.30 8.13 7.10
.... 8.68 9.07 8.63 7.35 4.70

Length of Fleece (centimeters)

Columbia ................... ........ 9.36 8.39 8.43 7.58 7.14 7.34 7.49
Native .......................... .... 8.17 7.35 7.32 6.58 6.34 5.70
F1 ......... ... ......... .... .... 9.30 8.24 7.95 7.73 7.35 7.13 7.73
F2 ................................. .... .... 9.15 8.35 8.30 7.85 6.60 ....

Columbia Sheep Productivity in Florida


Breeding Data on Productivity, Arranged According
of Ewes to Age of Ewes
2 Years | 3 Years 1 4 Years | 5 Years 6 Years I 7 Years
Percent of Ewes Lambing

Columbia .......... 37.5 50.0 66.7 61.5 55.6 66.7
Native .............. 71.4 70.0 93.3 57.1 100.0 ..
F1 .......... .......... .. 69.7 85.2 97.4 93.1 100.0 100.0
F= .............. .... 61.5 65.2 90.0 100.0 ...... .

Average Number of Lambs Born per Ewe

Columbia .......... 1.11 1.10 1.20 1.12 1.40 1.33
Native ....--....... 1.07 1.00 1.07 1.50 1.67
F, ....................... 1.09 1.20 1.47 1.56 1.60 1.67
F2 ...................... 1.33 1.50 1.56 1.00 ..

Colum bia ..........
N ative ...........
F1 .......................
F2 .................-....

Average Birth Weights (pounds)

7.35 6.88 8.29 7.29
7.03 8.21 7.90 9.27
8.51 8.56 8.40 9.08
8.47 8.29. 10.16 12.50

Average Weaning Weights (pounds)

61.60 70.30 71.62 76.12
56.00 66.36 65.38 68.00
75.30 76.80 76.27 74.75
76.41 76.96 81.00 88.00

61.75 76.00
73.80 ..
79.24 73.80

the Columbias in 3 and the Fi ewes in 4 cases. Columbia ewes
had significantly heavier fleeces than F, ewes at all ages. There
were no significant differences in length of fleece, and the ob-
served differences were in favor of the Columbias in 4 and the
Fi ewes in 3 cases.
F1 ewes excelled native ewes in body weight and weight of
fleece at all ages, and differences were significant in all cases.
The F1 ewes also excelled the native ewes in length of fleece at
all ages, except 1 year, and the differences in favor of the F1
ewes were significant in 4 out of 5 cases.
The F2 ewes were heavier than Fi ewes at all ages in which
comparisons were made, except at 5 years of age and in this
case only 1 F2 animal was involved, so little importance can be
attached to it, even though the difference between it and the
average of the F1 group was quite large. The F. ewes produced


Groups Compared 1

Differences in Size and Fleeces, G-ouped According to Age of Ewes

Birth I Weaning I 1 Year 2 Years 1 3 Years 4 Years 5 Years 1 6 Years 1 7 Years

Body Weight (pounds)

Columbia-Native ..... .05 13.94** 23.68** 43.73** 48.15** 51.69** 31.08** --
Columbia--F .........-... -.69* 1.93 -1.44 14.56* 5.40 8.55 -5.33 2.66 -17.33
Native-F1 ..: ..-.-- -.74** -12.01** -25.12** -29.17** -42.75** -43.14** -36.41**
F1 F ....................... -.12 -11.25 -15.45** -32.37** -21.42** -13.18 20.41**

Weight of Fleece (pounds)

Columbia-Native ...... .... .... 5.42 7.65 6.98** 8.15** 6.29** 7.91**
Columbia-F1 ........ .. .... 1.46* 2.80** 3.30** 4.43** 2.95** 4.68** 3.16**
Native-F1 ............... .... .... -3.96** -4.85** -3.68** -3.72** -3.34** -3.23**
F1 F2 ................ .... .... .... .18 .83 .81* 1.67** 3.60**

Length of Fleece (centimeters)

Columbia-Native .. .... .... -.06 1.04** 1.11** 1.00* .80 1.64**
Columbia-F1 ............ .... .... .06 .15 ..48 -.15 -.21 .21 -.24
Native-F ................. .... .... .12 -.89** -.63* -1.15** -1.01* -1.43
F, F2 ......................... ..... .15 -.11 -.35 -.12 .75** ......

1 When difference is in favor of second group listed, a minus sign is used. Otherwise, the difference is in favor of the first group listed.
P = .05 or less. ** P = .01 or less.

Columbia Sheep Productivity in Florida


Groups Differences in Productivity, Grouped According
Compared1 to Age of Ewes
2 Years 1 3 Years I 4 Years ( 5 Years 1 6 Years 1 7 Years
Percent of Ewes Lambing

Columbia-native 33.9 -20.0 -26.6 4.4 -44.4
Columbia-F .... -32.2 -35.2 -30.7 -31.6 -44.4 -33.3
Native-F1 .......... 1.7 -15.2 -4.1 -36.0 0.0
F F ................ 8.2 20.0 7.4 -6.9

Average Number of Lambs Born per Ewe

Columbia-native .04 .10 .13 -.38 -.27 ..
Columbia-F1 ...... .02 -.10 -.27 -.44** -.20 -.34
Native-F1 .......... -.02 -.20** -.40** -.06 .07
-F, 2 ................ .24 .30* .09 .56** ..... ...

Birth Weight (pounds)

Columbia-native .32 -1.33* .39 -1.98 -1.88
Columbia-F1 ...... -1.16 -1.68** -.11 -1.79 -1.84 -2.19**
Native-Fi .......... -1.48** -.35 -.50 .19 .04
F -F2 ............. .04 .27 -1.76** -3.42**

Weaning Weight (pounds)

Columbia-native 5.60 3.94 6.24 8.12 -12.05*
Columbia-Fi ...... -13.70** -6.50 -4.65 1.37 -17.49** 2.20**
Native-F1 .......... 19.30** -10.44 -10.89** -6.75 -5.44
F, F2............. -1.11 -.16 -4.73 -13.25** ..

1When difference is in favor of second group listed, a minus sign is used. Otherwise,
the difference is in favor of the first group listed.
P = .05 or less. ** P =.01 or less.

heavier fleeces than the F2 ewes at all ages and the differences
were significant in 3 out of 5 cases. Differences in length of
fleece were in favor of the Fi ewes in 2 cases and the F2 ewes in
3 cases. The differences in body weight in favor of the F2 ewes
are rather surprising and there is no clear-cut explanation of
them. It is possible that management and feeding improved
sufficiently during the course of the work to give the F2 ewes an
opportunity for larger growth and more adequate maintenance.
Columbia ewes tended to be less fertile than native ewes, as
measured by the percent of ewes lambing (see Table 4). In
4 out of 5 age groups in which comparisons could be made, a
higher proportion of the native ewes produced lambs. The dif-

Florida Agricultural Experiment Station

ferences were not large enough to be statistically significant in
any age group. There were no important differences between
Columbia and native ewes in the number of lambs per birth
among the ewes that were pregnant. Likewise, there were no
consistent differences in birth weight of the lambs produced.
Lambs from Columbia ewes were heavier at weaning in 4 out
of 5 age groups but these differences were not significant. It
should be remembered that the majority of the lambs from
native ewes were sired by Columbia rams, hence differences at
weaning time may be less than if native rams had been used on
native ewes.
F1 ewes consistently excelled Columbia ewes in the percent of
ewes lambing, although the difference was not statistically sig-
nificant in any case. They also excelled the Columbia ewes in
number of lambs born per pergnancy in 5 out of 6 cases. The
difference in favor of the Fi ewes was significant in only 1
age group. The over-all difference in fertility appears to be
definitely in favor of the F1 ewes. Lambs from the F1 ewes
were heavier at weaning in 4 out of 6 age groups.

Fig. 7.-Young ewes at Quincy. Left: Columbia, 16 months old, weighed
164 pounds, sheared fleece weighing 18.8 pounds; left center: Fi, 16 months
old, weighed 140 pounds, sheared fleece weighing 12 pounds. Right center:
F,, 16 months old, weighed 96 pounds, sheared fleece weighing 10 pounds;
right: native, lambed at North Florida Station, 27 months old, weighed
110 pounds, sheared fleece weighing 5.3 pounds.

Columbia Sheep Productivity in Florida

F, ewes excelled native ewes in percent of ewes lambing in
3 out of 5 age groups, but the differences were not significant.
In 1 group there was no difference. In number of lambs born
per pregnancy the Fi ewes excelled the natives in 4 out of 5 cases
and the difference was statistically significant in 2 of these 4
cases. Lambs produced by F1 ewes were heavier at birth in 3
out of 5 age groups, and the difference was significant in 1 of
these cases. Lambs from F1 ewes were heavier at weaning in
all age groups and the differences in their favor were significant
in 2 cases.
A higher percentage of F1 ewes than F2 ewes lambed in 3 out
of the 4 age groups compared. Differences in number of lambs
born per pregnancy were not consistently in favor of either
group. Lambs from F2 ewes were significantly heavier in birth
weight in 2 age groups, and in the other 2 groups small differ-
ences in favor of lambs from F1 ewes were not significant.
Lambs from F2 ewes were heavier at weaning in all 4 com-
parisons made but the difference was significant in only 1 case.
This apparent difference in weaning weight in favor of lambs
from F2 ewes may be accounted for by the fact that the ma-
jority of these lambs were sired by Columbia rams.
Data on wool fineness were not included in the analysis, since
only empirical visual evaluations were available and these did
not indicate any material differences in the fineness of wool
on the various types. The average fineness at side and thigh
in the various groups of ewes when 1 year old was as follows:
Spinning Count
Group Side Thigh
Columbia (raised at Quincy) .................... 54 48
Natives (raised at Quincy) ...................... 52 48
F .............................................. ............ 54 48
F .................. ........................... ............ ..... 54 50

The extensive data presented above may be more easily under-
stood if expressed in terms of the average yearly production of
a typical ewe. Figures of this type are presented in Table 9.
These are simple averages of the average production of the age
groups within each type of breeding presented in Tables 2, 5
and 6. They are intended to show the production per ewe per
year that would be expected for the ages included, which were as
follows: Weight and length of fleece-1 to 7 years; lambs born
per ewe-2 to 7 years (based on average number of lambs born
per pregnant ewe and average percent of ewes lambing from

Florida Agricultural Experiment Station


Average Yearly Production per Ewe of -
Group Grease Wool Length of Lambs Born Weaning
(pounds) Wool (No.perEwe) Weight
(_centimeters) (pounds)
Columbia-Dubois 11.56 8.66 1.15 81.6
Columbia-Quincy 12.00 8.55 .77 66.2

Columbia ........... 11.93 7.96 .68 69.6
Native --......--.......- .. 5.14 6.91 .99 65.9
F ............................ 8.68 7.92 1.30 76.0
F2 --------- --................ 7.69 8.05 1.07 80.6

2 to 7 years, except in the first phase where percent of ewes
lambing from 3 to 7 years was used. This latter age range was
used to eliminate bias because these ewes lambed at Dubois as
2-year-olds and there was a marked drop in lambing percentage
in the group moved to Quincy); average weaning weight-2 to
7 years. In cases where no data were available on 7 or 6-year-old
ewes, the remaining data were used.
A comparison of this type is admittedly rough, but it does
place the results of a complex experiment in a form where they
can be seen quickly and clearly.
The summary of the first phase of the experiment (see Table
9) shows that the wool production (grease weight and length)
was practically equal in Columbia ewes maintained at Dubois,
Idaho, and Quincy, Florida, but the ewes at Dubois reproduced
at a higher rate and their lambs weighed about 15 pounds more
per head at weaning time.
Columbia ewes raised at Quincy produced practically the same
amount of wool, with a trifle less length of staple, as those
Columbia ewes born at Dubois and either retained there or trans-
ferred to Quincy. The level of reproduction and the weaning
weight of lambs of the Columbia ewes raised at Quincy were
approximately the same as in those Columbia ewes that had
been transferred from Dubois. Thus, even though Columbia
ewes were raised from birth at Quincy, they were unable to
adapt themselves to the environmental influence that limited
their ability to reproduce at a high level.

Columbia Sheep Productivity in Florida

Columbia ewes raised at Quincy greatly excelled the native
ewes in grease weight of fleece and their staple was somewhat
longer. However, they did not reproduce as well as the native
ewes and their lambs were only slightly larger at weaning. The
majority of lambs from native ewes were sired by Columbia
rams, which probably gives the native ewes an undue advantage
in this comparison.
F1 and F2 ewes produced fleeces that were intermediate in
weight to the Columbia and native fleeces, and that were com-
parable to the Columbia fleeces in length of staple. They ex-
ceeded both parent types in average number of lambs born per
ewe and in average weaning weight per lamb.
The above findings indicate that Columbia sheep are not suf-
ficiently well adapted to conditions in northern Florida to re-
produce at their maximum efficiency. Their advantage in fleece
yield over native ewes was offset by the lower reproduction rate.
The actual economic advantage in any 1 year would be deter-
mined largely by the relative prices of wool and lambs. The
relative effects of various environmental influences, such as para-
site infestation and high summer temperatures, are not known.
If the poor showing of the Columbias, in terms of percent of
ewes lambing, was due largely to lower resistance to parasites,
then it may be possible to overcome this handicap through the
use of improved therapeutic agents, such as phenothiazine (13,
14, 15). Recent work by Miller and Monge (6) has emphasized
the variation in ability of sheep to maintain normal or nearly
normal body temperatures during the summer at College Station,
Texas, and the apparent positive relation of this ability to pro-
ductivity. Data are not available on the ability of animals in
this experiment to maintain normal body temperatures during
hot weather, but the results obtained in Texas indicate that this
may have been an important factor affecting reproductive per-
formance of the various groups.
The results indicate that, under conditions comparable to those
of this experiment, Columbia rams may be used very effectively
for crossing with native ewes. Ewes from this cross were inter-
mediate to Columbia and native ewes in weight of fleece, and
their performance as measured by lambs produced and weight
of lambs at weaning was superior to either of the parent types.
The present breeding work was not carried sufficiently far to
indicate clearly the best method of utilizing the crbssbreds in
further breeding operations, or to determine the amount of

Florida Agricultural Experiment Station

Columbia blood that could be used and still have sufficient re-
sistance to the environment. Assuming that one wishes to
maintain levels of approximately half Columbia and half native
blood, there are 2 procedures that might be used. One is to
continue with inter se matings. This eliminates need for Colum-
bia rams after the initial cross. If satisfactory progress towards
a new type is to be made, using this procedure, large numbers
of animals should be involved in the initial cross and culling
should be quite strict to eliminate the undesirable types that
segregate. The second possibility is to use a criss-cross system
of mating, in which Columbia and the most select native rams
are used in alternate generations.

Results are reported of 2 phases of an experiment to test the
usefulness of the Columbia sheep under Florida conditions.
In the first phase, 30 pairs of Columbia ewes and 2 pairs of
rams were selected from the Bureau of Animal Industry's flocks
at the U. S. Sheep Experiment Station, Dubois, Idaho. One
member of each pair was retained at Dubois and the other was
sent to the North Florida Experiment Station, Quincy. Wool
production of the ewes at Quincy, as measured by grease weight
and staple length, was comparable with that of the ewes at
Dubois, but the level of fertility as measured by percent of
ewes lambing was not as high. This deficiency was especially
marked during the first 2 years the ewes were at Quincy. Wean-
ing weight of lambs also was lower in the ewes at Quincy.
Columbia ewes descended from those brought from Dubois and
raised at Quincy also reproduced at a lower level and had smaller
lambs at weaning than Columbia ewes at Dubois.
In the second phase of the experiment, comparisons were niade
of Columbia, native, F1 and F2 ewes, all of which had been
raised at Quincy. In grease weight of wool the Columbias were
more than twice as high as the native ewes, and F1 and F2 ewes
were intermediate. There were no material differences in length
of staple between Columbia, F. and F2 ewes, and native wool
was only slightly shorter than that from Columbia ewes. There
were no important differences in spinning count of wool among
the 4 groups, as determined visually on yearling ewes. Native
ewes produced somewhat more lambs than Columbias, but
Columbia and native ewes did not differ materially in weight
of their lambs at weaning. The majority of the lambs from

Columbia Sheep Productivity in Florida

native ewes were sired by Columbia rams, however, so this
may have given the native ewes an undue advantage in this
latter comparison. Fi and F2 ewes exceeded both parent types
in the number of lambs produced and in weight of lambs at
The results indicate that, under the conditions of this experi-
ment, the Columbia sheep did not reproduce as efficiently in the
environment of northern Florida as under conditions at Dubois,
Idaho, where they were developed. However, ewes produced
by mating Columbia rams to native ewes reproduced at a level
superior to either parent strain and their fleeces were consider-
ably heavier than those of native ewes. .Hence, the use of Colum-
bia rams on native ewes may be recommended as an effective
means of increasing production.
Until more is known concerning the amount of Columbia blood
that can be introduced with safety, the Columbia x native ewes
may be utilized in further breeding operations by mating them
with rams of the same breeding, or a criss-cross system of mating
may be used in which Columbia and selected native rams are
used in alternate generations.

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Florida Agricultural Experiment Station

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