Effects of Feeding Aureomycin to Dairy Calves

This study was initiated to determine the effects of feeding crystalline aureomycin hydrochloride in milk from birth to 60 days, and in the concentrate mixture from 61 to 120 days, and of removing it at 61 and at 121 days. Calves fed 45 rag. daily per 100 lb. weight from birth to 60 days, gained 50 lb. as compared to 45.8 lb. for the controls. Those continued from 61 to 120 days on alfalfa hay plus concentrate containing 50 p.p.m, of the antibiotic, gained 76.1 lb. as compared to 66.4 lb. for the controls. Weight gain and hay consumption were significantly lowered when aureomycin was removed from six calves after 61 days. Responses of animals to removal of aureomycin varied from excellent gains in weight, feed intake, and appearance to conditions of anorexia, reduced growth, lachrymation, diarrhea, rough coat, and thick, scaly hide. Ed{tor.