268 - Growth Performance of Weaned Angus Bulls Housed in a Compost-bedded Pack Barn

Compost-bedded pack barns (CBP) are commonly utilized in dairy cattle operations across the United States. Their popularity is the result of improved animal welfare and reduced costs. The crossover of CBP into the beef cattle industry is new and the benefits and downfalls are not yet explored. Through a grant from NRCS, a CBP was built at the Morehead State University Derrickson Agricultural Complex in 2019-2020. In fall of 2020, the pack was established by mixing manure and sawdust shavings to start the aerobic composting process. The objective of our study was to determine the performance of growing bulls utilizing a CBP compared to a fully outdoor pasture housing system and measure the pack development. Growth data from 2 consecutive years of growing bulls were utilized, with calves born in 2019 being used as a control (CON) group and calves born in 2020 being used as the CBP group. Adjusted weaning and yearling weights reported to the American Angus Association were utilized to measure growth performance. Heifers born in both years were also evaluated as an outside standardization mechanism to eliminate genetic bias. Temperature measurements, surface and internal, were collected 3 times weekly to measure pack establishment. Weaning weights for CON and CBP bulls were similar (P = 0.45), though interestingly the corresponding heifer calves weaned with CBP bulls were heavier (P < 0.01) than those weaned with the CON bulls. Bulls housed in the CBP were significantly heavier (P < 0.01) as yearlings compared to the CON bulls (496 kg vs. 425 kg, respectively). Temperature differed (P < 0.02) between day, side of the barn, and measurement location. Our results suggest that utilizing a compost bedded pack barn during the winter growing phase may be beneficial to the producer by increasing growth potential of weaned calves.