Effect of Laidlomycin Propionate on Beef Bull Growth Performance and Reproductive Development

• Published in: Journal of Applied Animal Research Vol. 18; no. 2; pp. 137 - 147
• Main Authors: Downs, K. M., Kunkle, W. E., Marshall, T. T., Reiling, B. A., Yelich, J. V.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.12.2000
• Subjects: Bulls; laidlomycin propionate; reproduction; semen quality
• ISSN: 0971-2119; 0974-1844
• DOI: 10.1080/09712119.2000.9706335

Downs, K.M., Kunkle, W.E., Marshall, T.T., Reiling, B.A. and Yelich, J.V. 2000. Effect of laidlomycin propionate on beef bull growth performance and reproductive development. J. Appl. Anim. Res., 18: 137-147. The effects of laidlomycin propionate (LP) on beef bull growth performance and sexual development were determined in an 84 day study. Forty embryo transfer Angus bulls were fed three complete diets containing LP levels of either 0, 10 or 20g/t. Bulls were fed daily using electronic feeders to obtain individual feed intake. Full weight and scrotal circumference (SC) were evaluated at 28 day intervals. Breeding soundness examinations were conducted to characterize semen. Muscle mass and body fat were estimated using real-time ultrasonography. Laidlomycin propionate did not influence daily gain, dry matter intake, feed efficiency, subcutaneous or intramuscular fat deposition, but Longissimmus muscle deposition was enhanced. Among treatments, bulls had similar (P>0.05) SC measurements and no detrimental effects on semen quality or sperm morphology were observed. Supplementing growing bulls with laidlomycin propionate for improved performance did not detrimentally affect sexual development.