AS-366
April 1967

Summary
Value of Aureomycin and Sulfamethazine in Conditioning New Cattle
W. M. Beeson, T. W. Perry, and M. T. Mohler, Department of Animal Sciences
The value of feeding 350 milligrams of either aureomycin or sulfamethazine alone, or in combination, was studied in three shipping fever studies of 28 days each with newly-arrived feeder calves. The cattle were fed their respective drug treatments in 2.0 pounds of soybean meal or of Supplement A along with 2.0 pounds of ground shelled corn and roughage.
The cattle responded to the aureomycin treatment alone or to the combination of aureomycin and sulfamethazine (Table 1). Those administered 350 milligrams of aureomycin per head daily gained 28 percent faster than those which received no aureomycin. Those fed the combination of 350 milligrams aureomycin and 350 milligrams sulfamethazine gained 74 percent more rapidly than those which received neither and 36 percent more rapidly than those administered only aureomycin. Administration of sulfamethazine alone was without effect on gain. No cattle on the combination of aureomycin and sulfamethazine required medical attention; three animals on aureomycin alone, five animals on sulfamethazine alone and eight of the control animals required medical attention.
In another experiment, aureomycin alone was just as effective as a combination of aureomycin and sulfamethazine in stimulating rate of gain. Sulfamethazine alone gave no marked response in gain over those receiv-
ing none. Only one case of shipping fever required medical attention from the group of 80 animals in this experiment.
In a third experiment, there was a 0.3 pound per day response in favor of a combination of 350 milligrams aureomycin and 350 milligrams sulfamethazine per head daily over the control animals receiving no drugs.
Experimental Procedure
Research was conducted to study the response of newly-arrived feeder calves to supplemental aureomycin or sulfamethazine or the two in combination. In all three of the experiments the cattle were shipped from Alpine, Texas to Lafayette, Indiana, and were enroute approximately 30 hours.
Upon arrival at the Purdue University Livestock Research Barn the steers were ear-tagged, individually weighed and allotted to their respective treatments on a gate-cut basis. By this technique, the first calves off the truck were assigned to the control group whereas calves unloaded later in the sequence were assigned to the various treatments in order. This method of assigning the cattle to treatments was pursued to avoid extra handling of the animals.
The levels of medication used were 350 milligrams of aureomycin or 350 milligrams
Beef Section • Animal Sciences Department Cooperative Extension Service, PURDUE UNIVERSITY, Lafayette, Indiana
Beef  Nutrition