The Influence of Aureomycin on the Protein Requirement and Carcass Characeristics of Swine

Abstract
A combination feeding trial and slaughter experiment involving 54 pigs was conducted to determine the effect of aureomycin on protein requirement and to determine the effect of aureomycin and protein level on certain carcass measurements. The results of the experiment indicate that a corn-soybean oil meal ration well fortified with mineral and vitamins and containing 14.3 percent of crude protein was just as satisfactory for weight gains of healthy weanling pigs fed in drylot as rations containing 17.6 and 20.9 nercent of crude protein. There was no clear evidence that aureomycin enhanced protein utilization. Carcass studies indicated an increase, but not statistically significant, in backfat thickness as a result of aureomycin supplementation. Dressing percentages averaged slightly higher for the pigs that received the antibiotic and were significantly greater on the low and intermediate protein levels than on the high protein level. Carcass grades revealed an advantage for the group of pigs that received the high level of protein with no antibiotic added.