Mimeo A. H. 120 November 30, 1953
Purdue University
Agricultural Experiment Station Lafayette, Indiana
Aureomycin for Growing and Fattening Beef Animals
T. W. Perry, W. M. Beeson and M. T. Mohler Department of Animal Husbandry
Feeding antibiotic has proved to be beneficial for increasing growth rate and for preventing and alleviating scours in suckling calves. However, research data collected in the past has indicated that antibiotic feeding was of no benefit - and even detrimental in many cases - for old-er cattle and sheep in which rumen development had progressed much further. A review of this earlier work has shown that the antibiotics fed were either given at too high a level or that the feeding was discontinued too soon. Therefore, it was desirable to study the effect of feeding levels of antibiotic which differed from those reported unsuccessful earlier, and to study the effect of feeding antibiotic for a much longer time.
The objects of the four trials reported here were: (l) to investigate further the role of antibiotics for suckling calves; and (2) to investigate the effect of feeding antibiotics to cattle with more nearly fully developed rumens which were being fed either a predominantly roughage ration or a fattening type ration.
The Four Experiments Trial I. February 15 - October 11, 1951
Thirteen calves from the experimental Shorthorn herd were assigned to one of two treatments at time of birth. Twenty-four milligrams Aureomycin  per one hundred pounds liveweight were administered by capsule daily to six of the calves whereas the other seven received no aureomycin and served as controls. The calves ran with their dams in dry lot until pasture was available. A creep ration consisting of corn 66.7 percent, oats 20.0 percent, and soybean oil meal 13.3 percent was available both in drylot and on pasture. Data was collected on each calf until it reached 80 days of age.
Scouring seldom occurred in the lot receiving 24 milligrams aureomycin per 100 pound liveweight whereas scouring was a definite problem the control lot which received no aureomycin. Scouring in the control lot became so severe that therapy had to be undertaken. Aureomycin com-pletely cured all scouring when administered to the calves in the control lot. The amount required varied tremendously (from 12 mg. total to 231 mg. total) over a period of from one to three days.
Although the difference was not statistically significant, aureomycin calves averaged 14.5 pounds per calf more at 80 days of age than con-
calves not fed aureomycin. (Table I.)