Everglades Station Mimeo Report 57-8
March 20, 1957
AUREOMYCIN AND STILBESTROL FOR CATTLE FATTENED ON PASTURE
H. L, Chapman, Jr. and R. M, Hookeri/
1. Determine relative value of aureamycin and diethylstilbestrol, alone and
in combination in rations for steers fattened on pasture, as compared to
steers fed in dry lot.
2.. Determine effect on two different levels of concentrate intake upon the
value of the two "feed additives".
3. Compare value of orally administered diethylstilbestrol with stilbestrol
"implants" for cattle fattened on pasture.
Experimental Procedure: Experimental period November 2, 1956 through
March 18, 1957
One hundred and thirty-six grade two year old steers were divided into
17 lots of 8 animals each. Each lot contained 3 Hereford, 1 Charbray, 1 Bra-
ford, 1 Brahman x Angus, 1 Brahman and 1 Santa Gertrudis steers. The steers
averaged 765 pounds in weight, were average good in feeder grade and utility
in condition grade.
The design of the experiment was as follows:
Limited 0 Aureo.. Stilb. &
_ _J _. it
Full 0 Aureo. Stilb &
1/ Assistant Animal Nutritionist and Herdsman respectively,. University of
Florida, Everglades Experiment Station, Belle Glade, Florida
Animals on limited feed received six pounds daily of a concentrate mix-
ture compound of ground snapped corn, citrus pulp, cottonseed meal, urea and
cane molasses. This concentrate mixture was supplied at all times to the group
being fullfed. Aureomycin was fed at the rate of 90 rmg per animal daily.
Stilbestrol was fed at the rate of 10 mg. per animal daily. Stilbestrol was
implanted at the rate of 36 mg, per animal at the beginning of the experiment,
Average Daily Gain(lbs.)
0 Aureo. Stilb. &
SLimited 1.13 1.10 0,94 1,21
Dry Lot ________ ____ ____ ____
Full 241t 2.04 2,31 2457 2.29
Concentrate Feed Required per Pound of Grain(lbs.)
0 Aureo. Stilb. &
Limited 5,2 5.4 6.3 4.9
Dry Lot ______ ________ ________ _
S 91 13 9.1 8.Implant
Full 9.1 10.3 9.1 8.4 9.6
- -- --
Grass Silage Required Per Pound of Gain(lbs.)
0 Aureo. Stilbo &
Limited 40.5 40.2 43.8 36.4
Full 8.9 7.2 9.0 6.3
The average daily gain of steers on pasture as compared to dry lot are
shown in Table 1. The steers on pasture made a higher average daily gain than
steers in dry lot, on both levels of concentrate intake.
Table 1. Average daily gains of steers fattened in dry lot and on pasture.
Level of Average
Concentrate Daily Gain
Dry Lot 1.10
Dry Lot 2.25
Aureofac 10 was furnished by American Cyananid Company,
supplied by Eli Lilly and Company.