Effect of Avoparcin and Monensin on Feedlot Performance of Beef Cattle

Publisher Website
Google Scholar
Abstract
One hundred and fifty yearling steers weighing an average of 273 ± 23 kg were fed for 112 days to evaluate the effect of 0, 16.5, 33 and 66 ppm avoparcin and 3 3 ppm monensin in the feed on growth rate, feed efficiency, carcass quality and the concentration of volatile fatty acid (VFA) in the rumen. The steers were allotted to 25 pens with six head per pen in a randomized complete block design of five treatments and five replicates per treatment. Rumen samples were obtained from a randomly selected group of steers from each treatment at the end of the trial for VFA determination. Carcass grade, carcass weight and dressing percentage were determined at slaughter. Avoparcin at all levels improved feed efficiency and produced daily gains that were greater than untreated control or monensin treated steers. Ruminal propionate increased due to avoparcin ingestion. Neither avoparcin nor monensin had an effect (P> .05) on measured carcass parameters. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science.