Everglades Station Mimeo 62-23 April, 1962
Effect of Vitamin A on Steers Fattened,in
Drylot, With and Without Fangola Hay I/
H. L. Chapman, Jr., C. E. Haines and R. W. Kidder 2/
During recent years there has been increased information indicating the
need for providing beef cattle with synthetic Vitamin A in excess of levels
previously considered adequate. Under certain conditions there appears to be
poor conversion of the naturally-occurring carotenes to Vitamin A in the
animals' body. There are also several other factors affecting the requirement
of beef cattle for synthetic Vitamin A supplements, including the stage of the
life cycle of the animal, previous nutritional history, level of nitrate nitro-
gen in the diet, health of the animal, various nutritional interrelationships
and possibly environmental stress factors. A considerable amount of research
will be required to completely evaluate the need for supplemental Vitamin A
as affected by these various factors.
The purpose of the experiment in this report was t teaine the value
of supplementing a drylot steer fattening ration with t min palmita
and/or Pangolagrass hay.
Experimental Procedure- \ /
Thirty-two two-year-old Angus steers having an init age standard
slaughter grade were divided into four equal groups on these weight,
grade and previous treatment. The groups were then allotted at random to the
following experimental treatments:
Lot number Treatment per steer
1 No pangola hay, no Vitamin A
2 No pangola hay, 25,000 I.U. of Vitamin A
3 Pangola hay, no Vitamin A
4 Pangola hay, 25,000 I.U. of Vitamin A
All experimental animals received a full feed of concentrate feed mixture
comprised of 48.8 percent ground snapped corn, 40.0 percent dried citrus pulp,
10.0 percent of 41j cottonseed meal, 0.08 percent of Urea-262 and 0.04 percent
of a complete mineral mixture. The mixture, had a mixed cost of $2.81 per
hundred pounds. The Pangolagrass hay was produced in South Florida and cost
$37.00 per ton. The hay was full-fed. Vitamin A was added to the concentrate
feed at the rate of 25,000 I.U. per animal daily. The steers had been on
excellent Roselawn St. Augustinegrass pastures for 12 months prior to being
1/ Acknowledgement is made to Mack Barnwell, Enrique Tomeu, J. V. McLeod, R. L.
Shirley and others who assisted in the conduction of this experiment.
Acknowledgment is also made for the Vitamin A used in this study furnished
by Distillation Products, Inc., Rochester, N.Y.
2 Associate Animal Nutritionist, Assistant Animal Husbandman and Animal
Husbandman, respectively, Everglades Experiment Station.
placed in the drylot.
An initial slaughter grade was placed on each animal by a grading com-
mittee. The initial value per animal was based on the price of cattle of
similar quality at the Belle Glade Auction Market. The final value of each
animal was the actual average selling value. At the conclusion of the feeding
period the cattle were slaughtered in Miami and carcass data obtained. Cal-
culations for this information were made as follows.
Final weight Miami weight 1
a. Intransit shrink = Final weight
Warm carcass weight X 100
b. Unadjusted dressing percent = Miami weight
Warm carcass weight cold carcass weight
c. Cooler shrink = Warm carcass weight
The summary of average weight changes, carcass data and cost data per
steer are presented in Table one. Supplemental Vitamin A increased rate of
gain slightly when Pangola hay was not fed but the difference was not stat-
istically significant. The inclusion of Pangola hay significantly increased
rate of gain. The differences in rate of gain of each group were related to
the intake of dry matter. Vitamin A and/or Pangola hay did not significantly
effect intransit shrink, dressing percent, cooler shrink or change in grade.
Vitamin A and/or Pangola hay steers had a higher increase in slaughter
grade than steers receiving no Vitamin A or hay, which was expressed in higher
returns per steer over initial steer value and feed costs.
Table 1. Summary of average weight changes, carcass data and cost data per
animal for steers on Vitamin A study in drylot (on test 116 days).
No Pangola hay Pangola hay
Vitamin Vitamin Vitamin Vitamin
A A A A
Number of animals 8 8 8 8
Final weight (Ibs.) 968 968 997 979
Initial weight (Ibs.) 712 706 708 708
Total gain (Ibs.) 256 262 289 271
Daily gain (ibs.) 2.21 2.26 2.49 2.34
Final slaughter grade 11 12 12 12
Initial slaughter grade 7 7 7 7
Increase in slaughter grade (1/3) 4 5 5 5
Intransit shrink (%) 4.13 3.82 3.81 3.88
Unadjusted dressing percent (%) 61.53 61.87 63.09 62.49
48-hour cooler shrink (%) 2.28 2.26 2.31 2.55
Final animal value ($) 222.80 233.23 244.85 237.80
Initial animal value ($) 142.40 141.20 141.60 141.60
Total feed costs:
Concentrate feed ($)2/ 66.79 70.87 73.54 72.27
Pangola Hay --- --- 6.46 5.64
Return over initial steer value
and feed costs ($) 13.61 21.16 23.20 18.29
I/ Effect of Pangola hay significant at P = 0.01.
2/ Cost of Vitamin A not included.
EES Mimeo 62-23