Abstract
Clenbuterol [benzyl alcohol, 4-amino-α-(t-butylamino)methyl-3,5-dichloro] was tested in a high concentrate diet for its effects on performance and body composition of finishing crossbred wethers in three studies each of 8 wk duration. In Exp. I, administration of clenbuterol at 0, 1, 10 and 100 ppm resulted in feed:gain ratios of 8.13, 7.91, 7.51 (P>.05) and 6.73 (different from control P<.05), respectively, with no change in average daily gain. Dressing percentage, longissimus muscle area (LA) at the 12th rib and protien content of the hindquarters were increased and fat content decreased by treatment (all P<.01). In Exp. II, clenbuterol was administered at 0, .5, 2 and 10 ppm. Feed efficiency and average daily gain were not affected by treatment. Dressing percentage, LA and protein content of the hindquarters were increased and fat content of the hindquarters decreased by treatment (all P<.01). In Exp. III, treatment with 2 ppm clenbuterol in comparison with control showed 263 vs 212 g for average daily gain, 6.72 vs 8.31 for feed/gain, 57.2 vs 54.6% for dressing percentage and 23.85 vs 16.85 cm2 for LA (all P<.01). These data suggest that treatment with clenbuterol causes a repartitioning of nutrients resulting in improved feed conversion, reduced fat deposition and increased muscle deposition. Copyright © 1984. American Society of Animal Science . Copyright 1984 by American Society of Animal Science