Effects of Chlortetracycline, Inedible Animal Fat, Stilbestrol and High and Low Quality Roughage on Performance of Yearling Steers

Abstract

Forty-eight steers were individually fed in a factorially designed experiment to determine the effects of chlortetracycline, stilbestrol, fat, and roughage on digestibilities of dry matter, crude fiber, ether extract, and crude protein. Using the lignin ratio technique, under the condition of this experiment, it was found that chlortetracycline significantly decreased the digestibility of ether extract. Fat, fed as 7% of the ration, significantly reduced the digestibility of dry matter and crude fiber but increased the digestibility of ether extract. Stilbestrol did not influence the digestibility of either the dry matter, crude fiber, crude protein or ether extract. A higher digestibility of dry matter occurred in groups fed the alfalfa rations than in those fed wheat straw. The digestibility of ether extract was higher in straw-fed steers than in steers fed the alfalfa ration. The mode of action of chlortetracycline, stilbestrol, or fat in either increasing or decreasing digestibility was not determined.