The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
15 AUG 5 )Y4
Bulletin 389 June, 1943
UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
WILMON NEWELL, Director
COMPARATIVE VALUE OF
GRAZING CROPS FOR
FATTENING FEEDER PIGS
By W. G. KIRK, L. O. GRATZ and V. E. WHITEHURST, JR.
Fig. 1.-Feeder pigs used in Lot 9, sweet potatoes and tankage, in the
EXECUTIVE STAFF BOARD OF CONTROL
John J. Tigert, M.A., LL.D., President of the H. P. Adair, Chairman, Jacksonville
University3 R. H. Gore. Fort Lauderdale
Wilmon Newell, D.Sc., Directors N. B. Jordan, Quincy
Harold Mowry, M.S.A., Asso. Director T. T. Scott, Live Oak
L. O. Gratz, Ph.D., Asst. Dir., Research Thos. W. Bryant, Lakeland
W. M. Fifield, M.S., Asst. Dir., Admin.' J. T. Diamond, Secretary, Tallasassee
J. Francis Cooper, M.S.A., Editors
Clyde Beale, A.B.J., Assistant Editors BRANCH STATIONS
Jefferson Thomas, Assistant Editors NORTH FLORIDA STATION, QUINCY
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Managers J. D. Warner, M.S., Agronomist in Charge
K. H. Graham, Business Manager R. R. Kincaid, Ph.D., Asso. Plant Pathologist
Claranelle Alderman, Accountants Elliott Whitehurst, B.S.A., Asst. An. Husb.4
W. C. McCormick, B.S.A., Asst. An. Husb.
MAIN STATION, GAINESVILLE Jesse Reeves, Asst. Agron., Tobacco
W. H. Chapman, M.S., Asst. Agron.4
AGRONOMY Mobile Unit, Monticello
W. E. Stokes, M.S., Agronomist' R. W. Wallace, B.S., Asso. Agronomist
Fred H. Hull, Ph.D., Agronomist Mobile Unit, Milton
G. E. Ritchey, M.S., Associates Ralph L. Smith, M.S., Asso. Agronomist
W. A. Carver, Ph.D., Associate CITRUS STATION. LAKE ALFRED
Roy E. Blaser, M.S., Associate A. F. Camp, Ph.D., Horticulturist in Charge
G. B. Killinger. Ph.D., Associate V. C. Jamison, Ph.D., Soils Chemist
Fred A. Clark, B.S.A., Assistant B. R. Fudge, Ph.D., Associate Chemist
ANIMAL INDUSTRY W. L. Thompson. B.S., Associate Ento.
A. L. Shealy, D.V.M., An. Industrialist s F. F. Cowart, Ph.D., Asso. Horticulturist
R. B. Becker, Ph.D., Dairy Husbandmans J. W. Sites, Ph.D., Asso. Hort.
E. L. Pouts, Ph.D., Dairy Technologists W. W. Lawless, B.S., Asst. Horticulturist'
D. A. Sanders, D.V.M., Veterinarian R. K. Voorhees, Ph.D., Asso. Plant Path.
M. W. Emmel. D.V.M., Veterinarians H. 0. Sterling, B.S., Asst. Hort.
L. E. Swanson, D.V.M., Parasitologist T. W. Young, Ph.D., Asso. Hort., Coastal
N. R. Mehrhof, M.Agr., Poultry Husb.s C. R. Stearns, Jr., B.S.A., Chemist
T. R. Freeman, Ph.D., Asso. in Dairy Mfg. EVERGLADES STA.. BELLE GLADE
R. S. Glasscock, Ph.D., Asso. An. Husb. J. R. Neller, Ph.D., Biochemist in Charge
D. J. Smith, B.S.A., Asst. An. Husb.4 J. W. Wilson, Sc.D., Entomologist4
P. T. Dix Arnold. M.S.A., Asst. Dairy Husb.3 F. D. Stevens, B.S., Sugarcane Agron.
G. K. Davis, Ph.D., Tech. in An. Nutrition Thomas Bregger, Ph.D., Sugarcane
S. P. Marshall, M.S., Asst. in An. Nutr. Physiologist
L. E. Mull, M.S., Asst. in Dairy Tech.' G. R. Townsend, Ph.D., Plant Pathologist
O. K. Moore, M.S., Asst. Poultry Hush. R. W. Kidder, M.S., Asst. An. Hush.
C. B. Reeves, B.S., Asst. Dairy Tech. W. T. Forsee, Ph.D., Asso. Chemist
J. E. Pace, B.S., Asst. An. Hush. B. S. Clayton, B.S.C.E., Drainage Eng.2
ECONOMICS AGRICULTURAL F. S. Andrews, Ph.D., Asso. Truck Hort.'
C. V. Noble, Ph.D., Agr. Economist' Roy A. Bair, h.D., Asst. Agron.
Zach Savage, M.S.A., Associate C. M innum, M.S., Asst. Truck Hort.
A. H. Spurlock, M.S.A., Associate N. C. Hayslip, B.S.A., Asst. Entomologist
Max E. Brunk. M.S., Assistant SUB-TROPICAL STA., HOMESTEAD
Geo. D. Ruehle, Ph.D., Plant Path. in Charge
ECONOMICS, HOME S. J. Lynch, B.S.A., Asst. Horticulturist
Ouida D. Abbott, Ph.D., Home Econ.1 E. M. Andersen, Ph.D., Asst. Hort.
Ruth O. Townsend, R.N.. Assistant
R. B. French, Ph.D., Asso. Chemist W. CENT. FLA. STA.. BROOKSVILLE
ENTOMOLOGY C. D. Gordon, Ph.D., Asso. Poultry Geneticist
ENTOMOLOGY in Charges
J. R. Watson, A.M., Entomologist in Ch
A. N. Tissot, Ph.D.. Associate RANGE CATTLE STA., ONA
H. E. Bratley, M.S.A., Assistant W. G. Kirk, Ph.D., An. Hush. in Charge
E. M. Hodges, Ph.D., Asso. Agron., Wauchula
HORTICULTURE Gilbert A. Tucker. B.S.A., Asst. An. Husb.'
G. H. Blackmon, M.S.A., Horticulturist' R. A. Fulford, B.S.A., Asst. An. Husb.
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Hort. FIELD STATIONS
R. J. Wilmot, M.S.A., Asst. Hort. Leesburg
RD. D ickey, M.S.A., Asst. Hort.4 M. N. Walker, Ph.D., Plant Path. in Charge'
J. Carlton Cain, B.S.A.. Asst. Hort.4
Victor F. Nettles, M.S.A., Asst. Hort.4 Plant City
Byron E. Janes. Ph.D., Asst. Hort. A. N. Brooks. Ph.D.. Plant Pathologist
A. L. Kenworthy, M.S., Asst. Hort. Hastings
F. S. Lagassee, Ph.D., Asso. Hort.2 A. H. Eddins, Ph.D., Plant Pathologist
II. M. Sell. Ph.D., Asso. Hort.2 E. N. McCubbin, Ph.D.. Asso. Truck Hort.
PLANT PATHOLOGY Monticello
W. B. Tisdale, Ph.D., Plant Pathologist1 3 S. O. Hill. B.S., Entomologists 4
George F. Weber, Ph.D.. Plant Path.s A. M. Phillips, B.S., Asst. Entomologist2
Phares Decker, Ph.D.. Asso. Plant Pathologist Sanford
Erdman West. M.S., Mycologist R. W. Ruprecht, Ph.D., Chemist in Charge
Lillian E. Arnold, M.S., Asst. Botanist Jack Russell, M.S., Asst. Entomologist
R. V. Allison, Ph.D., Chemist' s Jos. R. Beckenbach, Ph.D., Truck Hort. in
Gaylord M. Volk, M.S.. Chemist Charge
F. B. Smith, Ph.D., Microbiologists E. G. Kelsheimer, Ph.D., Entomologist
C. E. Bell, Ph.D., Associate Chemist F. T. McLean, Ph.D., Horticulturist
J. R. Henderson, M.S.A., Soils Technologist A. L. Harrison, Ph.D., Asso. Plant Path.
L. H. Rogers, Ph.D., Asso. Biochemist David G. Kelbert, Asst. Plant Pathologist
Richard A. Carrigan, B.S., Asso. Chemist4 Lakeland
L. E. Ensminger, Ph.D., Asso. Soils Chem. E. S. Ellison, Meteorologists 4
H. W. Winsor, B.S.A., Assistant Chemist Harry Armstrong, Asso. Meteorologist2
Geo. D. Thornton, M.S., Asst. Chemist
T. C. Erwin, Assistant Chemist Head of Department.
J. N. Howard, B.S., Asst. Chemist 2 In cooperation with U. S.
R. E. Caldwell, M.S.A., Soil Surveyor4 3 Cooperative, other divisions. U. of F.
Olaf C. Olson, B.S., Soil Surveyor4 ) On leave.
COMPARATIVE VALUE OF GRAZING CROPS FOR
FATTENING FEEDER PIGS
By W. G. KIRK,1 L. O. GRATZ2 and V. E. WHITEHURST, JR.3
Introduction ..................... ................. 3 Records ..................... ........................... 6
Experimental Procedure .............................. 3 Experimental Results ......... ................ 7
Grazing Crops and Supplements .......... 4 Summer Grazing Trials ........................ 7
Experimental Animals ............................. 6 Winter Grazing Trials ........................... 11
M ethod of Grazing Crops ........................ 6 Summ ary ................................................... ........... 14
Most of the hogs in North Florida are fattened for market
by allowing them to "hog-off" crops and crop combinations con-
sisting mainly of peanuts, corn and sweet potatoes. In many
sections peanuts are the most economical crop for this purpose,
while in others corn and sweet potatoes are more satisfactory.
Cowpeas and native vegetation are used to supplement the sum-
mer fattening crops, and oats and rye are used with the winter
crops. Their value for fattening depends upon the following
factors: Time of year the crops are available for fattening;
gains produced per acre of crop; amount of supplemental feed
required to balance the ration; labor, seed and fertilizer neces-
sary to produce the crop.
Corn and Spanish peanuts planted early in the spring will be
sufficiently mature from July 1 to 15 to permit grazing, while
Florida Runner peanuts and sweet potatoes can be used in Octo-
ber. Thus, by growing a variety of crops, pigs can be fattened
for market over an extended period. A combination of crops
not only gives a desirable and nutritious feed supply but also
lessens the danger of a shortage of feed where only 1 crop is
The object of the series of summer and winter grazing trials
reported herein was to determine the relative value of different
crops and crop combinations for fattening feeder pigs.
Grazing trials with summer and winter fattening crops were
conducted at the North Florida Experiment Station, Quincy,
SFormerly Assistant Animal Husbandman, Main Station; now in charge,
Range Cattle Station.
Formerly Plant Pathologist in Charge, North Florida Station; now
assistant director, research.
3 Assistant Animal Husbandman, North Florida Station, on military
4 Florida Agricultural Experiment Station
from July 1937 to January 1941. Five lots of feeder pigs were
used in each of 3 summer trials and 4 lots in each of 3 winter
trials. Since the results of the third trial with sweet potatoes
varied greatly from those obtained previously, a fourth trial was
conducted in 1940-41. The fields used for these trials had an
area of 1.95 acres. The soil type was predominantly Orangeburg
fine sandy loam, grading into Magnolia and Ruston fine sandy
GRAZING CROPS AND SUPPLEMENTS
The following feeds were used in the summer fattening trials:
Lot 1. Corn alone.
Lot 2. Corn supplemented with 60 percent tankage.4
Lot 3. Corn and cowpeas interplanted.
Lot 4. Corn and Spanish peanuts in alternate rows.
Lot 5. Spanish peanuts alone.
The winter fattening trials included the following feeds:
Lot 6. Florida Runner peanuts alone.
Lot 7. Florida Runner peanuts supplemented with 60 per-
Lot 8. Florida Runner peanuts and green oats supplemented
with 60 percent tankage.
Lot 9. Sweet potatoes supplemented with 60 percent tankage.
The crops were grown according to accepted farm practices.
The corn was planted in 4-foot rows; corn and cowpeas inter-
planted in 3.5-foot rows; corn and Spanish peanuts in alternate
3.5-foot rows, and Spanish peanuts in 2.5-foot rows. All winter
grazing crops were grown in 3.5-foot rows. The fertilizer for
growing the crops consisted of the following mixture: Super-
phosphate 18 percent, 1,100 pounds; 8 percent cottonseed meal,
300 pounds; nitrate of soda, 200 pounds; and muriate of potash,
250 pounds. It was applied at rates varying from 100 to 628
pounds per acre, depending on the crop (see Table 1). Most of
the summer grazing crops were side-dressed with nitrate of soda.
The crops were cultivated frequently enough to control weeds
and grass during the growing season. In periods of heavy rain-
fall a large amount of hand labor was necessary to control weeds
in the peanut and sweet potato crops. There was considerable
growth of grass after the crops were "laid by" because of fre-
quent summer rains.
'Fish meal was used free choice in Trial I and tankage in Trials II
Value of Grazing Crops for Fattening Feeder Pigs 5
The variety of corn used in all summer trials was Florident
Yellow. For Lot 3 the corn was interplanted with Black Crowder
cowpeas. For Lot 4 corn and Spanish peanuts were grown in
alternate rows. Spanish peanuts were planted alone in Lot 5.
Florida Runner peanuts were used in the winter grazing trials.
For Lot 8, oats were planted between the rows when the peanuts
were nearly mature to provide succulent grazing during the test
period. The Porto Rican variety of sweet potatoes, commonly
raised for human consumption, was grown for Lot 9.
In general the following system of crop rotation was practiced:
The fields which had been used in the summer grazing trials
were planted to oats in October. The oats were pastured through-
out the winter and spring months. In May the land was prepared
and planted to Florida Runner peanuts and sweet potatoes
to be used the following winter. After the winter trials were
completed, corn, cowpeas and Spanish peanuts were planted in
preparation for the summer fattening trial. Thus in a 2-year
period all fields produced 3 crops, 2 for fattening purposes and
1 for green grazing.
F A t
i. '. at "
Fig. 2.-A water supply system such as that shown here was supplied each lot.
6 Florida Agricultural Experiment Station
The feeder pigs had access at all times to fresh water (Fig. 2)
and to the following mineral mixture :
Steamed bonemeal ................... ..... .... .......... 50 pounds
Calcium carbonate (ground limestone) ............ 50 pounds
Comm on salt ..............-----..... ...--.......... ........ ..... .. 25 pounds
Red oxide of iron ---..................--.......-----.... ..... 25 pounds
Copper sulfate ............--....... ..--- .. .....--- .... 1 pound
Purebred Poland China feeder pigs, both barrows and gilts,
were used in all trials. Early spring farrowed pigs were used
in the summer fattening trials while late summer and early fall
pigs were used in the winter tests. The pigs were divided as
uniformly as possible into their respective groups according to
age, weight, sex and feeder grade. Figures 1 and 2 show the
type of feeder pigs used.
The number of pigs in the different lots depended upon the
amount of feed available in the fields. For ease in handling and
disposal after the various trials were completed, an attempt was
made to have sufficient pigs on each crop to graze the field in
approximately the same number of days. However, there was
considerable variation in length of the feeding period, as Tables
2 and 4 show.
METHOD OF GRAZING CROPS
At the beginning of each trial the pigs were given access to
only 1/ of the field. When this area was grazed the temporary
fence was moved to include the second 1/%, and finally was re-
moved altogether to allow the pigs access to the whole field.
This method of grazing reduced the loss of feed in periods of
heavy rainfall and also the amount of peanuts and corn eaten
A labor record was kept of the man, mule and machine hours
required to produce each crop as well as the amount of fertilizer
used and seed sown.
Samples of each crop were gathered from 10-foot sections of
4 representative rows in each 1/3 of the field immediately prior to
allowing pigs in that area. Yield estimates were made from
air-dried and shelled corn, from air-dried and unshelled peanuts,
and freshly dug sweet potatoes.
The mineral mixture recommended for swine feeding at the present
time contains 2 ounces of either cobalt chloride or cobalt sulfate or 1 ounce
of cobalt carbonate.
Value of Grazing Crops for Fattening Feeder Pigs 7
The pigs were weighed individually on 3 consecutive days at
the beginning of each trial and once a week throughout the trial.
When the feed was practically all consumed, weights were ob-
tained daily or as often as necessary to determine when the pigs
ceased to gain. When this occurred each lot was taken off test.
SUMMER GRAZING TRIALS
The comparative average hours of man, mule and machine
labor to produce each crop are given in Table 1. The amounts
of seed and fertilizer used in the production of the different
TABLE 1.-AVERAGE HOURS OF LABOR, AMOUNT OF SEED AND FERTILIZER
USED IN THE PRODUCTION OF AN ACRE OF CROP OR CROP COMBINATIONS
USED IN SUMMER AND WINTER GRAZING TRIALS.
Crops o 0 Seed Used ) 4 "0
Summer Grazing Crops
1 Corn ....---........... 24 16 1.4 9.7 pounds 300 125
2 Corn ---................... 24 17 1.1 9.7 pounds 300 125
Corn 9.7 pounds
3 Corn interplanted Cowpeas 37
with cowpeas .... 29 17 1.4 pounds 300 125
4 Corn and Spanish Corn 5 pounds
peanuts alter- Spanish peanuts
nate rows .......... 31 17 1.1 0.8 bushel 250 62.5
5 Spanish peanuts 57 22 1.6 2.4 bushels 200 -
Winter Grazing Crops
6 Florida Runner
peanuts ........----.... 56 23 2.0 1.2 bushels 200
7 Florida Runner
peanuts .............. 52 22 2.0 1.2 bushels 200
8 Florida Runner Peanuts 1.2
peanuts and bushels
green oats ........ 55 25 2.0 Oats 0.5 bushel 100 -
9 Sweet potatoes .. 128 12.1 11.1 12,000 draws 628 -
Barnyard manure at the rate of 6 tons per acre was applied annually to all lots.
8 Florida Agricultural Experiment Station
crops and crop combinations used in the summer grazing trials
are given also.
It will be observed that Spanish peanuts required more hand
labor, mule, and machine hours than did corn. This extra work
was necessary to keep the grass and weeds under control. The
amount of seed sown and fertilizer applied can be used in esti-
mating the approximate cost of producing the various crops.
It should be borne in mind that these trials were conducted
on land favorable for corn. With lands more adapted to peanuts
a different relationship may be expected between the cost of
producing the crops and in pork production per acre.
Results obtained from each of the summer fattening trials
are presented in Table 2.
TABLE 2.-NUMBER OF PIGS, LENGTH OF GRAZING PERIOD, INITIAL AND
FINAL WEIGHTS, GAINS, AND FEED REQUIRED PER 100 POUNDS OF GAIN
FOR FEEDER PIGS USED IN EACH OF THE THREE SUMMER GRAZING TRIALS.
STotal s Feed Required to Pro-
B Weight duce 100 Pounds Gain
0 ^ per Lot P
*m4 0 0 ,E
Lot 1. Corn Alone
7/9/37 7 55 725 1,390 665 1.73 341 660 -
7/15/38 8 101 720 1,675 955 1.18 490 756 4.03
7/25/39 8 93 660 1,505 845 1.14 433 640 4.89
Lot 2. Corn and Tankage*
7/9/37 7 55 743 1,535 792 2.06 406 577 17 -
7/15/38 8 81 720 1,870 1,150 1.77 590 518 29 0.13
7/25/39 8 93 670 1,845 1,175 1.58 603 527 22 1.08
Lot 3. Corn and Cowpeas* Interplanted
"7/9/37 i 8 57 827 1,530 703 1.54 361 707
7/15/38 8 95 700 1,805 1,105 1.45 567 710 3.87
7/25/39 8 93 680 1,510 830 1.12 426 659 2.87
Lot 4. Corn and Spanish Peanuts, Alternate Rows
7/9/37 4 71 412 920 508 1.79 261 485 143 --
7/15/38 5 101 445 1,210 765 1.51 392 613 61 2.50
7/25/39 6 85 498 1,100 602 1.18 309 543 36 4.27
Lot 5. Spanish Peanuts Alone
7/9/37 4 57 407 825 418 1.83 214 578 -
7/15/38 4 90 355 955 600 1.67 308 461 2.63
7/25/39 4 63 355 685 330 1.31 169 403 4.42
Fishmeal used in 1937, tankage in 1938 and 1939.
** No estimate was made of the amount of cowpeas, forage or pods eaten.
t No record of mineral consumed in 1937 test.
Value of Grazing Crops for Fattening Feeder Pigs 9
In all summer grazing trials there was an abundant supply
of green feed in the fields which supplemented the grazing crops.
It is seen from Table 2 that there was considerable variation
in the number of swine grazing days, gain per acre, average
Fig. 3.-Finished hogs fattened on corn and Spanish peanuts.
Fig. 4.-Finished hogs from the peanut and peanut and corn plots at the
end of the 1939 summer grazing trial.
10 Florida Agricultural Experiment Station
daily gain per pig and quantity of feed required per 100 pounds
of gain from year to year with pigs on the same feed. The
average initial weight of the pigs used in the 1937 grazing test
was 14.7 and 19.6 pounds heavier than in the 1938 and 1939
tests, respectively. This is one reason for greater average daily
gain in each lot in 1937 compared with gains made in 1938
A summary of the results of the summer grazing trials is
given in Table 3.
TABLE 3.-SUMMARY OF RESULTS OF THREE SUMMER GRAZING TRIALS WITH
SLot 1 Lot 2 Lot 3 I Lot 4 L Lot 5
Corn and Spanish! Spanish
Grazing crop and Corn and cowpeas peanuts peanuts
supplements fed alone tank- inter- in alter-! alone
age planted nate
Total number of pigs .................. 23 23 24 15 12
pounds pounds pounds pounds pounds
Average initial weight per pig .. 91.5 92.7 92.0 90.3 93.1
Average final weight per pig .... 198.7 228.3 201.9 215.3 205.4
Average gain per pig .................. 107.2 135.6 109.9 125.0 112.3
Average daily gain per pig ......-. 1.27 1.75 1.35 1.44 1.60
Average gain per acre of crop 421 533 451 321 230
Average feed requirements
for 100 pounds gain:
Corn ........................--............... 691 536 693 556 -
Cowpeas ...-......................-.. - -
Spanish peanuts ................... - 75 483
Tankage .......................... --- 23.2 -
Mineral supplement** ..-.....- 4.43 0.61 3.43 3.28 3.27
No estimate was made of the amount of cowpeas, forage or pods eaten.
** Average for the last 2 grazing trials.
In the 3 summer grazing trials the pigs on corn alone, Lot 1,
made an average daily gain of 1.27 pounds, gained 421 pounds
per acre of crop, and required 691 pounds of corn per 100 pounds
of gain. In comparison the pigs in Lot 3, grazing corn and cow-
peas, made an average daily gain of 1.35 pounds, gained 451
pounds per acre of crop and required 693 pounds of corn for each
100 pounds of gain. Frequent observation indicated that the
pigs ate little if any cowpeas, either leaves or pods.
The pigs on corn supplemented with tankage, Lot 2, made
the highest average daily gain, 1.75 pounds, and gain per acre,
Value of Grazing Crops for Fattening Feeder Pigs 11
533 pounds. For each 100 pounds of gain these pigs ate 536
pounds of corn and 23.2 pounds of tankage. This amount of
tankage saved 155 and 157 pounds of corn compared with Lots
1 and 3, respectively. Thus 1 pound of tankage saved approxi-
mately 6.72 pounds of corn. It is seen from Table 3 that feeding
tankage reduced the mineral consumption to less than 1/5 of the
amount eaten by the pigs in any of the other 4 lots.
The pigs grazing corn and Spanish peanuts, Lot 4, gained 321
pounds per acre of crop which was 100 pounds less than the pigs
on corn alone, 212 pounds less than those on corn supplemented
with tankage, 130 pounds less than the lot on corn and cowpeas
and 91 pounds more than the pigs on Spanish peanuts. Lot 4
required 556 pounds of corn and 75 pounds of Spanish peanuts
for each 100 pounds of gain.
Lot 5 on Spanish peanuts had an average daily gain of 1.60
pounds, gained 230 pounds per acre of crop and required 483
pounds of peanuts for 100 pounds of gain.
WINTER GRAZING TRIALS
The average hours of man, mule and machine labor, seed and
fertilizer used in the production of Florida Runner peanuts alone
and combined with oats and of sweet potatoes are given in Table
1. Approximately the same amount of labor was required to
produce Florida Runner as Spanish peanuts.
Sweet potatoes required over twice as much hand labor as did
the peanut crop because the draws were set by hand and the
growth of vines late in the growing season prevented cultivation
by mule-drawn implement.
Results obtained from each of the 3 winter grazing trials with
Florida Runner peanuts and the 4 trials with sweet potatoes are
given in Table 4.
Variation in gains from year to year for pigs on the same
winter fattening crops was as great as with the summer fatten-
ing crops. Average daily gain for all lots on Florida Runner
peanuts in 1938-39 was lower and more feed was required to
produce 100 pounds of gain than in either the preceding or suc-
ceeding trials. Unfavorable weather during the 1938-39 grazing
trial resulted in considerable numbers of sprouted peanuts which
were unpalatable to the pigs.
Average initial weight of the pigs in the 1940-41 trial with
sweet potatoes was 113 pounds, the heaviest of any of the pigs
used. They were placed on trial on November 13, 3 weeks later
than in the previous year but 3 and 4 weeks earlier than in the
12 Florida Agricultural Experiment Station
first and second trials, respectively. The pigs in the third and
fourth trials scoured excessively; this was considered the cause
of the low average daily gains compared with those for the first
2 trials. It is seen from Table 4 that the pigs on sweet potatoes
in the fourth trial ate 98 pounds of tankage for each 100 pounds
of gain, the largest amount for any of the 4 trials. Scouring
occurred in spite of heavier initial weight and the increased con-
sumption of tankage.
TABLE 4.-NUMBER OF PIGS, LENGTH OF GRAZING PERIOD, INITIAL AND
FINAL WEIGHTS, GAINS, AND FEED REQUIRED PER 100 POUNDS OF GAIN
FOR FEEDER PIGS USED IN EACH OF THE WINTER GRAZING TRIALS.
a Total -4 Feed Required to Pro-
4 0 Weight ^. p duce 100 Pounds Gain
9Q 0 Mper Lot a. q r.
Lot 6. Florida Runner Peanuts
12/15/37 390 5 C' 64 55 -
12/23/38 79 298 755 457 1.16 234 739 3.72
10/23/39 5 59 440 970 530 1.80 272 382 3.53
Lot 6. Florida Runner Peanuts
12/15/37 4 68 390 835 445 1.64 228 535 -
12/23/38 5 79 298 755 457 1.16 234 739 0 3.72
10/23/39 5 59 440 970 530 1.80 272 382 4 3.53
Lot 7. Florida Runner Peanuts and Tankage
12/15/37 4 68 396 840 444 1.63 444 451 20 -
12/23/38 5 69 284 775 491 1.42 252 601 20 1.45
12/23/39 6 59 515 1,170 655 1.85 336 287 24 1.30
Lot 8. Florida Runner Peanuts, Tankage and Green Oats
12/15/37 4 68 393 860 467 1.72 239 484 12 12 -
12/23/38 5 74 289 835 546 1.48 280 514 12 0.92
10/23/39 6 59 510 1,125 615 1.74 315 344 19 1.50
Lot 9. Sweet Potatoes**
12/15/37 10 68 997 1,930 933 1.37 478 3,846 72 -
12/23/38 12 91 705 2,165 1,460 1.34 749 4,265+ 64 0.27
10/23/39 14 87 1,150 2,200 1,050 0.86 538 2,574 69 0.76
11/13/40 12 62 1,355 2,054 699 0.92 358 3,557 98 0.29
No record kept of minerals consumed in 1937-38 tests.
** Four trials with sweet potatoes.
t Estimated that at least 1/5 of sweet potatoes were not eaten by pigs because of spoil-
age. This amount was deducted from total yield and not included in the above amount.
The sweet potatoes required for 100 pounds of gain ranged
from 2,574 pounds in 1939-40 to 4,265 pounds in 1938-39. In
Trial II it was estimated that at least 1/% of the potatoes spoiled
because of unfavorable weather and this amount was deducted
from the total yield. In every trial there was considerable loss
of feed, since the tubers rooted out of the ground deteriorated
rapidly and became unpalatable. Thus, the amount of potatoes
required per 100 pounds of gain appeared to be excessively large
even in the most favorable fattening trial.
Value of Grazing Crops for Fattening Feeder Pigs 13
TABLE 5.-SUMMARY OF RESULTS OF THREE WINTER GRAZING TRIALS WITH
FLORIDA RUNNER PEANUTS AND FOUR TRIALS WITH SWEET POTATOES.
Lot 6 Lot 7 Lot 8 Lot 9
Florida Florida Runner Sweet
Grazing crop and Runner Runner peanuts, potatoes
supplement fed peanuts peanuts green and
alone I and oats and tankage
Total number of pigs .........-.-- ... 14 15 15 48
pounds pounds pounds pounds
Average initial weight per pig .. 80.6 79.7 79.5 87.6
Average final weight per pig ....; 182.9 185.7 188.0 173.9
Average gain per pig ................. 102.3 106.0 108.5 86.3
Average daily gain per pig ........ 1.49 1.69 1.74 1.11
Average gain per acre of crop .. 245 272 278 531
Average feed requirements
for 100 pounds gain:
Florida Runner peanuts ...... 542 430 445
Green oats .....-.................- .. --- ad lib -
Tankage ....... ...-..--- ..----- --. 21.5 14.8 67.8
Sweet potatoes .................... - 3,998
Mineral supplement .......... --3.62 1.36 1.23 0.43
It is seen from Table 5 that the pigs grazing Florida Runner
peanuts alone, Lot 6, made an average daily gain of 1.49 pounds,
Fig. 5.-Pigs fattened on peanuts alone, peanuts and tankage, and peanuts,
green oats and tankage in the third winter grazing trial.
14 Florida Agricultural Experiment Station
gained 245 pounds per acre of crop and required 542 pounds of
peanuts per 100 pounds of gain.
There is no appreciable difference in average daily gain, gain
per acre, or peanuts eaten per 100 pounds of gain between the
pigs in Lot 7 on peanuts supplemented with tankage, and those
in Lot 8 on peanuts and green oats supplemented with tankage.
The most striking fact in the winter grazing trials was that
an average of approximately 6 pigs could be fattened on an acre
of sweet potatoes and less than 3 pigs on an acre of peanuts.
Although the average daily gain is the lowest, 1.11 pounds, the
gain per acre is much greater than the total gains from any of
the peanut areas. In Table 1 it has been shown that the produc-
tion of sweet potatoes required more hand labor and a larger
amount of commercial fertilizer. In addition the cost of the
draws was greater than seed for other crops. These factors
have to be considered in estimating the value of the various feed
crops for fattening feeder pigs.
It is seen from Table 5 that the pigs on peanuts alone ate
over 21/2 times as much mineral mixture as did those on peanuts
and tankage and 3 times as much as those on peanuts, green oats
and tankage. The mineral consumption of pigs on sweet potatoes
was less than 1/8 that of those grazing peanuts alone.
Grazing trials with summer and winter fattening crops were
conducted at the North Florida Experiment Station, Quincy,
from July 1937 to January 1941. Ninety-seven pigs were used
in the summer trials and 92 in the winter trials.
The pigs grazing corn supplemented with tankage made an
average daily gain of 1.75 pounds and produced 533 pounds of
pork per acre, the highest of any of the crops or crop combina-
tions. They required 536 pounds of corn and 23.2 pounds of
tankage per 100 pounds of gain. This tankage saved 155 pounds
of corn per 100 pounds of gain compared with corn fed alone and
157 pounds when corn and cowpeas were interplanted.
The pigs on corn and cowpeas interplanted gained on the aver-
age 451 pounds per acre of crop and those on corn alone 421
Corn and Spanish peanuts in alternate rows produced 321
pounds of pork, which is 100 pounds less pork per acre than corn
alone and 130 pounds less than corn and cowpeas.
Value of Grazing Crops for Fattening Feeder Pigs 15
Spanish peanuts produced 230 pounds of pork per acre, the
lowest of any of the crops.
The pigs grazing Florida Runner peanuts alone made an aver-
age daily gain of 1.49 pounds and a total gain of 245 pounds
per acre of crop.
Supplementing Florida Runner peanuts with tankage increased
the average daily gain to 1.69 pounds and the pork produced per
acre to 272 pounds, while supplying tankage and green oats re-
sulted in an average daily gain of 1.74 pounds or 275 pounds
gain per acre of crop.
When tankage was fed 21.5 pounds saved 112 pounds of pea-
nuts per 100 pounds of gain, while 14.8 pounds of tankage and
green oats saved 97 pounds of peanuts.
Sweet potatoes gave the lowest average daily gain, 1.11 pounds,
and the largest total gain, 531 pounds per acre, of the winter
Approximately 6 pigs could be fattened on an acre of sweet
potatoes and less than 3 on Florida Runner peanuts.
In 2 trials with sweet potatoes excessive scouring in the graz-
ing pigs reduced the average daily gain to 0.86 and 0.92 pound.