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 Experimental procedure
 Experimental results
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Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 635
Title: Factors influencing winter gains of beef calves
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 Material Information
Title: Factors influencing winter gains of beef calves
Series Title: Bulletin - University of Florida Agricultural Experiment Station ; 635
Physical Description: Book
Language: English
Creator: Peacock, F. M.
McCaleb, J. E.
Hodges, E. M.
Kirk, W. G.
Publisher: University of Florida Agricultural Experiment Station
Publication Date: 1961
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Bibliographic ID: UF00027641
Volume ID: VID00001
Source Institution: University of Florida
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Table of Contents
    Front Cover
        Page 1
    Table of Contents
        Page 2
    Review of literature
        Page 3
    Experimental procedure
        Page 4
        Page 5
        Page 6
    Experimental results
        Page 7
    Discussion of experimental results
        Page 8
        Page 9
    Summary and conclusions
        Page 10
    Literature cited
        Page 11
    Back Cover
        Page 12
Full Text





FACTORS INFLUENCING
WINTER GAINS
OF BEEF CALVES

Bulletin 635
September 1961





























Fig. 1.-(Frontispiece) Calves grazing pangolagrass pasture and fed an
average daily supplement of 1.31 pounds cottonseed meal and 2.63 pounds
citrus pulp, March 1960.


CONTENTS
Page
Introduction --..-.--.--- ..... ......... .............. 3

Review of Literature .... ................................ ..... .... .. 3

Experimental Procedure ........................................--- ---. ....-- 4

Experim mental Results ... -.....- .... -. ............- ......-..--- 7

Discussion of Experimental Results .......... ...... ............... ........ 8

Summary and Conclusions ... -.......................... ..-..- ..- ...-. .....-- 10

Literature Cited ... ........ .. .... ................... .. .. ..... -- ...-.. ... ... 11









FACTORS INFLUENCING WINTER

GAINS OF BEEF CALVES

F. M. PEACOCK, J. E. MCCALEB, E. M. HODGES and W. G. KIRK'

Wintering beef calves is an important part of a ranching
operation, either for heifers to be used for replacements or steers
to be utilized at a later period. Good quality calves generally
can be purchased in the fall-when the supply on the market
is the largest-and wintered economically by utilizing available
roughage and a limited amount of concentrate feed. The cost
per 100 pounds usually will be less using this method than that
of purchasing comparable quality feeder animals on the spring
markets. Selecting the most economical means of maintaining
a desired rate of growth is essential to the success of this practice.
Roughage is the basic feed for growing beef cattle; there-
fore, it is an important part of any wintering ration. Pasture
forage is often in short supply during the fall and winter months,
and quality is variable, making it necessary to provide supple-
mental roughage. The value of hay for wintering all classes of
beef cattle is well known, but heavy and persistent rainfall makes
grass difficult to cure during the summer months. The practice
of ensiling summer grass in peninsular Florida is increasing
since this can be done when hay-making is hindered by rainfall.
A majority of the beef cattle in south Florida have Brahman
blood. Few data are available comparing the relative effects of
heredity and environment on the post-weaning growth of beef
calves with varying percentages of Brahman breeding.
Objectives of this study were to determine the effects of
pangolagrass roughage as pasture and silage, and proportion of
Brahman breeding and sex of weanling calves on their winter
gains. Information on the response of calves to different man-
agement and feeding practices is essential in developing a satis-
factory wintering program.

REVIEW OF LITERATURE
Feeding pangolagrass silage to calves has not been practiced
extensively. Baker (2)2 concluded that Argentine bahiagrass

1Assistant Animal Husbandman, Assistant Agronomist, Agronomist and
Vice-Director in Charge, Range Cattle Experiment Station, Ona, Florida.
SLiterature cited.






Florida Agricultural Experiment Stations


silage plus 3.0 pounds of a supplement was not a satisfactory
ration for wintering calves. Results were also unfavorable when
calves grazed frosted bahiagrass pasture while being supple-
mented daily with 4.5 pounds ground snapped corn and 1.5 pounds
cottonseed meal per head.
Limited data are available from which to evaluate the rela-
tive effects of heredity and environment on the growth rate of
Brahman crossbred cattle. Knapp and Nordskog (3), in a pre-
liminary study of growth in British-bred cattle, found that rate
of gain was highly heritable. Knapp and Clark (4), in studying
genetic and environmental correlations between growth rate of
beef cattle at different ages, concluded that heredity plays a
most important part in determining gains of calves in the feed
lot. Their results indicated that gains during the third 84-day
portion of the feeding period were as good a measurement as
was total gain over the entire 252-day feeding period. These
results agree favorably with those reported by Koger et al (5),
in which 13-year records at College Ranch of New Mexico showed
that sires influenced weaning weight and grade, yearling weight
and gain, feed lot gains and grade and productivity of daughters.
Peacock and Kirk (8), in fattening calves of different propor-
tions of Brahman and Shorthorn breeding, found no significant
difference in daily gain but a highly significant difference in feed
efficiency for gain in favor of the Brahman calves and a statis-
tically significant difference in carcass grade in favor of the
Shorthorn calves.
Results are not available on effect of sex on gains made dur-
ing the post-weaning period by cattle of the age and breed com-
position used in this study; however, it is assumed that variations
in weaning weights due to sex are constant and are expressed
in the same magnitude in post-weaning growth.

EXPERIMENTAL PROCEDURE
A 3-year study to measure the effect of certain breed com-
binations, forage feeding practices and sex on winter gains of
beef calves was initiated in October 1957. All calves used in this
study were raised at the Range Cattle Experiment Station, Ona,
Florida. Calves were born between January 1 and April 1 each
year and weaned around September 15, averaging 7 months of
age. A slaughter grade and type score for each calf was obtained
by averaging the scores of a committee of 3 graders. The calves
were kept in pens and fed a ration of hay and concentrates for






Factors Influencing Winter Gains of Beef Calves


7 to 10 days until they had quieted down after weaning and were
on feed. Prior to placing calves on trial, individual weights were
taken and the calves were assigned to treatment groups on the
basis of weight, sex, and breed composition. Breeding of calves
ranged from purebred Brahman to purebred Shorthorn with
both steers and heifers included in each lot.
The study included 168 calves in 1957-58, 177 in 1958-59 and
151 in 1959-60, a total of 496 animals. During the test periods,
which averaged 137 days, individual weights were taken at ap-
proximately 30-day intervals, and animals were fed and observed
daily. Calves were sprayed at weigh-time to control hornflies.
Pangola forage with limited supplemental feeding, involving
the wintering of calves was used as follows: 1, silage stored in
an above-ground bunker silo self-fed by means of a moveable
stanchion; 2, silage fed in bunks; 3, silage fed in bunks plus
limited grazing; 4, on pasture.














Fig. 2.-Calves self-fed pangolagrass silage from bunks and given an
average daily supplement of 1.31 pounds cottonseed meal and 2.63 pounds
citrus plup, March 1960.

Design of the experiment and amount of supplement fed to
calves are given in Table 1.
Pangolagrass was cut with a forage harvester in July and/or
August of each year. The cut grass was stored in a horizontal
bunker-type silo 161/2 feet wide, 7 feet high and 100 feet long,
with a computed capacity of over 200 tons. Moisture content
of the silage when fed averaged 68 percent in 1957, 74 in 1958
and 60 in 1959, the variations being due to the maturity of the
grass when ensiled. A chemical analysis of the silage is given
in Table 2.







Florida Agricultural Experiment Stations


TABLE 1.--AVERAGE DAILY RATION RECEIVED BY CALVES IN THE 4 FORAGE
GROUPS FOR THE 3 TRIALS.

Silage Silage Silage
Trial Ingredients from from Plus Pasture
No. Pounds Silo Bunks Pasture
I I
1 Pasture ............. limited ad lib.
Silage .......... .. ad lib. ad lib.
Cottonseed meal .. 1.39 .... 1.39 1.17
Citrus pulp .......... 2.78 .... 2.78 2.34
Cottonseed hulls ..... 0.41
Mineral ............. 0.08 .... 0.08 0.07

2 Pasture ...... ... .. ad lib.
Silage ............. .... ad lib. 25.30
Cottonseed meal 1.01 1.01 .... 1.01
Citrus pulp ......... 2.02 2.02 2.02
SMineral ............... 0.06 0.06 ...- 0.06

3 Pasture ... ..[-...... .. ... I ad lib.
SSilage ............. ad lib. 14.40
Cottonseed meal 1.31 1.31 .. 1.31
Citrus pulp ...... 2.63 2.63 .... 2.63
Mineral ...... 0.04 0.04 ... 0.04
_____________I_

TABLE 2.-PERCENT COMPOSITION OF PANGOLAGRASS SILAGE PRESERVED IN A
HORIZONTAL SILO.'


1957-58 1958-59 1959-60
J I
Dry matter, fresh-weight basis ..... 32 26 40
Dry matter, air-dry basis .......... 94.52 92.62 91.36
Crude protein ................... .. 3.08 6.70 5.47
Ash ....... .......... ......... ............ 5.86 4.85 7.48
Ether extract ... ......1.34 2.52 1.51
Crude fiber ............................. 33.03 35.13 30.47
Nitrogen-free extract ....... ... .. | 51.21 43.42 46.43
Calcium ........... .. ... ...... .32 .29 .42
M agnesium ............... ..... .... .. .13 .31 .24
Phosphorus ............................... .26 .20 .21

All chemical analyses reported on air-dry basis. Dry matter content of silage as fed
is reported under "fresh-weight basis." Analyzed by Dr. John T. McCall, Animal Nutrition
Laboratory.

Silage was fed daily to calves eating from the feed bunks ex-
cept week-ends when enough was fed on Saturday to take care
of Sunday. Spoilage was removed from the self-fed silo 3 times
weekly, with the exposed face evened at this time to insure the
calves having access to the silage.
Calves self-fed silage had access to a 10-acre field adjoining
one end of the silo, and calves fed silage in bunks were in an







Factors I,, dl. o ,,,.in Winter Gains of Beef Calves


adjacent 18 acres. Both areas were unimproved with scattered
carpetgrass mixed in the native grasses and saw palmetto.
Pangolagrass pastures grazed in this study were cut for
silage in August and treated with 400 pounds per acre of 10-10-10
or similar analysis fertilizer after cutting. This was followed
with 150 pounds per acre of ammonium nitrate by October 1.
Additional nitrogen was necessary because of the heavy plant
food removal during the silage harvest. Thirty acres of pangola-
grass, divided into 3 fields, were required to furnish forage for
the 51 to 59 calves in the pasture group. Rotational grazing
was used to obtain maximum forage utilization.
In addition to roughage, all calves received daily a concentrate
ration consisting of 1 part cottonseed meal and 2 parts citrus
pulp, plus 2 percent complete mineral. The average amount fed
daily in each trial is given in Table 1. Calves had access to clean
drinking water and Range Station complete mineral at all times.
The data were classified by forage practice, proportion of
Brahman breeding and sex of calves. The effects of these factors
on winter gains were determined by the method of least squares
as outlined by Anderson and Bancroft(1).

EXPERIMENTAL RESULTS

The overall average daily gain of the 496 calves during the
3 trials of 137 days was 0.63 pound. Adjusted daily gain means
for roughage are given in Table 3. The highest daily gain was
made by calves grazing pangolagrass pasture, followed by calves
having silage free-choice and limited access to pasture. Third
in rate of gain were calves self-fed silage from bunks, with those
self-fed silage from the silo being at the low end of the gain

TABLE 3.-EFFECT OF SOURCE OF ROUGHAGE ON DAILY GAINS ADJUSTED FOR
YEAR, SEX AND BREEDING.
I Adjusted Deviation
Source of Roughage No. ] Daily from
Calves [ Gain Mean

Silage self-fed from silo 165 0.47 0.15
Silage hand-fed from bunks 110 0.5;; 0.09
Silage self-fed from silo plus
limited pasture 5........ ... 57 0.70 + 0.08
Pangolagrass pasture ............ 164 0.78 + 0.16







Florida Agricultural Experiment Statiotns


record. There was a highly significant difference between daily
gains of calves on pangolagrass pasture and those fed silage.
Differences between breed composition of calves were signifi-
cant at the .05 level of probability. The 1/, Brahman calves had
the highest daily gain, while calves with more than 1/ Brahman
made higher gains than calves with less than 12 Brahman
breeding. The /-) Brahman calves gained 0.17 pound per day
more than the 1/8 to no Brahman and 0.08 pound per day
more than calves with 7/ to all Brahman breeding. Adjusted
mean gains for breeding of calves are shown in Table 4.

TABLE 4.-EFFECT OF BREED COMPOSITION OF WEANLING CALVES ON DAILY
GAINS ADJUSTED FOR YEAR, SEX AND ROUGHAGE.
Adjusted Deviation
Breeding No. Daily from
Calves Gain Mean
/s-purebred Brahman .....-..-.. 97 0.65 + 0.02
% 3 Brahman .............. ...... 19 9 0.64 + 0.01
/2 Brahman ................ ........... 89 0.73 + 0.10
% 1 Brahman ... ................. 66 0.57 0.06
/%-no Brahman ....... ... ... 45 0.56 0.07


Differences between sexes were significant at the .05 level of
probability. Steer calves gained 0.06 pound daily more than
heifer calves. The adjusted means for sex of calves are shown
in Table 5.

TABLE 5.-EFFECT OF SEX OF CALVES ON DAILY GAINS ADJUSTED FOR YEAR,
BREEDING AND ROUGHAGE.

Sex No. Adjusted Deviation
Calves Daily Gain from Mean
Males ....................... 304 0.66 + 0.03
Females ............. 192 0.60 0.03


DISCUSSION OF EXPERIMENTAL RESULTS

Response of calves to feed is determined by size of animal,
inherent capacity to gain, environment and the quantity and
availability of the nutrients in the ration. A calf has a limited
intake capacity, which makes it necessary to feed a ration high






Factors Influencing Winter Gains of Beef Calves


enough in nutrients for the desired gain. Differences in average
daily gain of calves fed pangolagrass silage from bunks, silage
self-fed from silo and grazing pangolagrass pasture are highly
significant. These results indicate that more nutrients were ob-
tained by calves on pasture than by those fed silage, even though
the forage was frosted and dry during the major portion of the
3 trials.


















Fig. 3.-Calves self-fed pangolagrass silage through a moveable stan-
chion. Average daily supplement consisted of 1.01 pounds cottonseed meal
and 2.02 pounds citrus pulp, February 1959.

Winter weather conditions ranged from extremely hard in
1957-58 to less critical in 1958-59 and back to severe in 1959-60.
Rainfall amounting to 21.4 inches during the first trial, coupled
with 18 days when there was frost, deteriorated the pangolagrass
reserved for grazing. Little or no growth occurred during this
period, and an average of 3 pounds of cottonseed hulls was fed
per animal daily to the pasture group during the last 38 days
of Trial 1. Rainfall was 15.23 inches in the 1958-59 trial and
15.96 inches in 1959-60, with 10 days of frost in Trial 2 and 13
in Trial 3. Average rainfall (6) for a 16-year period up to 1958,
from October through the following February, was 10.7 inches.
Calves on pasture made satisfactory gains under these abnormal
weather conditions.
There was a trend for calves eating silage free-choice from
bunks to gain slightly more than those self-fed from the silo.
This may have been partially due to greater ease of getting






Florida Agricultural Experiment Stations


silage from the bunks. Calves self-fed from the silo had to pull
forage from the packed silage mass, with room for only 14
calves to eat through the stanchions at a time, necessitating
their moving in and out. However, animals had access to silage
24 hours each day for the entire feeding trial.
Differences in gain between calves with varying percentages
of Brahman blood were significant at the .05 level of probability.
It is possible that if the trial period had been longer than 137
days, differences between breed groups would have been larger.
Stewart (9), in a report on breeding productive beef cattle, states,
"The effects of the milk and feed the calf received before wean-
ing extend into the period after weaning. For this reason it is
necessary to measure the gains after weaning over a period of
6 months or more if the calf is on feed, and over a period of 1
year if on roughage and pasture."
Results of this study show differences at the .05 level of prob-
ability between the steer and heifer calves for rate of gain. Here
again, an extended feeding period might have changed the level
of significance.
Genetic make-up of a calf determines the animal's potential
performance. This can be fulfilled by proper environment, or it
can be lost by conditions that are not sufficient to bring out these
qualities. Morrison (7) states that a minimum gain of 0.50
pound per day is required by calves that are to graze poor-quality
pasture the following summer and 0.75 to 1.00 pound weight
gain per day for calves to graze high-quality pasture. Under
the conditions of this study all lots of calves made the minimum
requirement for average daily weight gains of 0.50 pound through
the winter period. Results indicate that slight differences were
present and might have been more pronounced had the period
of treatment continued until the inherent gaining capacity of
the calves could have been expressed. Calves making the mini-
mum daily gains required for good results on high-quality
pasture the following spring and summer were the 1/ Brah-
man calves and those calves receiving pangolagrass pasture as
roughage.
SUMMARY AND CONCLUSIONS
A total of 496 weanling calves of Brahman and Shorthorn
breeding was fed in 3 wintering trials averaging 137 days to
determine the effect of different forms of pangolagrass rough-
ages, breed composition of calves and sex of calves on daily win-







Factors I, f,,. .i ,', iT Winter Gains of Beef Calves 11

ter gains. Adjusted average daily weight gains were 0.47 pound
for calves self-fed from the silo, 0.53 for those on silage from
feed bunks, 0.70 when self-fed from silo plus limited pasture,
and 0.78 for calves receiving roughage from pangolagrass pas-
ture. Calves grazing pangolagrass pasture had the highest daily
gain, while those self-fed pangolagrass from the silage had the
lowest.
Calves with breed composition of 7/ to purebred Brahman
gained 0.65 pound daily; .') to :, Brahman, 0.64 pound; 1/2
Brahman, 0.73 pound; aH to 1 Brahman, 0.57; and %1 to no
Brahman calves gained 0.56 pound daily. The /2 Brahman calves
had higher daily gains than calves with more than 1/2 or less
than 1/ Brahman. Steer calves gained 0.66 pound daily, while
heifer calves gained 0.60 pound, a difference of 0.06 pound daily
in favor of the steer calves.
Under the conditions of this study all lots of calves made
weight gains necessary for good results with cattle grazing low-
quality pasture the following spring and summer, while the 1/i
Brahman and those calves wintered on pangolagrass pasture
made weight gains for grazing high-quality pasture.

LITERATURE CITED
1. Anderson, R. L., and T. A. Bancroft. Statistical theory in research.
1st ed. McGraw-Hill Book Co., New York. 1952.
2. Baker, F. S., Jr. Wintering stocker cattle. N. Fla. Exp. Sta. Mimeo
Rept. 58-5. 1958.
3. Knapp, Bradford, Jr., and Arne W. Nordskog. Heritability of growth
and efficiency in beef cattle. Jour. An. Sci. 5:1. 1946.
4. Knapp, Bradford, Jr., and R. T. Clark. Genetic and environmental cor-
relations between growth rates of beef cattle at different ages. Jour.
An. Sci. 6:2. 1947.
5. Koger, Marvin, J. H. Knox, W. E. Watkins and K. A. Valentine. Selec-
tion of bulls. N. Mex. Agr. Exp. Sta. Bul. 359. 1951.
6. McCaleb, J. E., and E. M. Hodges. Climatological records at Range
Cattle Experiment Station, 1942-1958. Agr. Exp. Sta. Cir. S-124.
1960.
7. Morrison, F. B. Feeds and feeding. 22nd ed. Morrison Publ. Co., Ithaca,
N. Y. 1956.
8. Peacock, Fentress M., and W. G. Kirk. Feedlot performance and carcass
grades of Brahman and Brahman-Shorthorn steers. Fla. Agr. Exp.
Sta. Bul. 597. 1958.
9. Stewart, H. A. Breeding productive beef cattle. N. C. State College
Rept. 5. 1952.


































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