| Material Information
||Influence of age on weight of dam and weaning weight of calves
||3 leaves : ; 28 cm.
||Peacock, F. M ( Fentress McCoughan ), 1922-
Range Cattle Station, Ona
||Range Cattle Station
||Place of Publication:
||Calves -- Feeding and feeds -- Florida ( lcsh )
Calves -- Weight -- Florida ( lcsh )
Beef cattle -- Weight -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||F.M. Peacock ... et al..
||"February 1, 1971."
||Mimeo report (Range Cattle Station, Ona) ;
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 86109360
Range Cattle Station *
RCS 71-4 i nA. Ui. 1, 1971
INFLUENCE OF AGE ON WETGHTiOF DA AND
WEANING WEIGHT OF CALVES
F.M. Peacock, W.G. Kirk, M. Koger and E.M. Hodgesl/
The weaned weight of calf reflects the cows' productive
ability at any stage of maturity. Under normal conditions cows
reach maturity between 5 to 7 years of age and up to this time
there is a gradual increase in size. Generally, the size of
fetus is controlled by the size of the uterus and in two or three
year old heifers the calf is usually smaller than from older
cows. Cows which have not reached adult size continue to grow
and during this period compete with the fetus for available
The capacity of a cow to take in feed, which is associated
with size, influences performance. An immature female must take
in enough nutrients to nourish the fetus, maintain her condition,
and also support continued growth. After the calf is born, she
must have sufficient feed to provide milk for the calf and also
take care of maintenance and growth.
Research in New Mexico with Hereford cows showed a gradual
increase in cow weight and production up to 7 years of age with
the peak of production being between 6 and 8 years. After this
l/ Associate Professor; Animal Scientist Emeritus; Range Cattle
Experiment Station, Ona, Florida; Animal Geneticist, Gainesville,
Florida; and Agronomist, Range Cattle Experiment Station, Ona.
2/ Koger, M. and J.H. Knox, Effect of Age on the Weight and
Production of Range Cows. New Mexico A & M and Agr. Exp. Sta.
Press Bul. 1004. 1945
age there was a gradual decrease in production. This work demon-
strated a close correlation between size of cow and weaning weight
of calf, both associated with age of cow. Results of the New
Mexico work are given in table 1.
Table 1. THE WEIGHT OF COWS AT DIFFERENT AGES AND THE WEIGHT
OF CALVES PRODUCED (NEW MEXICO).
Age of Cow Weight of Cow Weight of Calf
3 908 387
4 952 405
5 983 429
6 1013 447
7 1024 454
8 1017 450
9 993 436
10 981 422
A study of cow performance at the Range Cattle Station,
showed an increase in weight of calf with cow age up to 6 years
and not much change through 18 years of age./ These data were
from Brahman and Brahman crossbred cows, indicating a longer
productive life than reported for other breeds.
Data on production of the original purebred Brahman cows
at the Range Cattle Station showed increased calf weight up to
5 years of age with little change through age 14. Calves were
crossbred Shorthorn-Brahman sired by Shorthorn bulls. Data
from these cows by age, weight, and 205 day weight of calf are
given in table 2.
3/ Peacock, F.M., W.G. Kirk, E.M. Hodges, W.L. Reynolds and
M. Koger. Genetic and Environmental Influences on Weaning
Weight and Slaughter Grade of Brahman, Shorthorn and Brahman-
Shorthorn Crossbred Calves. Fla. Agr. Exp. Sta. Tech. Bul.
-- 3- ..-
Table 2. THE WEIGHT OF BRAHMAN COWS AT DIFFERENT AGES AND WEAN
WEIGHT OF CROSSBRED CALVES. (FLORIDA)
Age of Cow Weight of Cow Weight of Calf
3 714 418
4 796 436
5 881 468
6 920 468
7 973 488
8 978 462
9 1018 457
10 1028 469
11 1038 468
12 1033 463
13 975 455
14 992 454
Very little research has been reported as to reason of
decline in production of cows after reaching maturity. Research
conducted with rats has shown that increasing protein, calcium,
vitamin A and riboflavin beyond the minimum requirements in
the diet resulted in increased life and production.L/ Older
animals were not able to assimilate and use calcium as efficiently
as when they were younger. We can assume that after cows have
reached their peak and are in a declining stage it is necessary
to improve their nutritional status in order to sustain production.
i/ Morrison, F.B. Feeds and Feeding. p 183, 21st Ed. The
Morrison Publishing Company, Ithaca, N. Y. 1949.
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
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site maintained by the Florida
Cooperative Extension Service.
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