Interpretive Summary: Evaluation of cattle sub-species and growth-promoting technology on growth performance, carcass characteristics, and enteric gas flux of steers finished in winter feedlot conditions
By: Ashley K Schilling-Hazlett, Kimberly R Stackhouse-Lawson, Tony C Bryant, Sara E Place, John P Ritten, Juan J Vargas, Irene A Reis, Edilane C Martins, Maya A Swenson, Erin N Burke, Rhyse K Campion, Cesar Velasquez, Anna M Shadbolt, Pedro H V Carvalho
Growth performance and gas flux in winter conditions were determined for Bos taurus indicus (BI; Brahman) and Bos taurus taurus (BT; Angus) steers managed with (GPT+) and without (GPT−) the use of growth-promoting technology (GPT). During the first 84 d, despite BI having heavier initial body weight (IBW), BT had greater dry matter intake (DMI), feed efficiency (G:F), and average daily gain (ADG), corresponding to greater final body weight (FBW). Also, GPT increased ADG, G:F, and FBW. During the last 96 d of the experimental period, growth performance observations were consistent with the first 84 d, but demonstrated that the effect of GPT use differed by cattle sub-species for DMI on a total daily and percentage of BW basis, as well as for G:F. More USDA Choice and Prime quality grades were observed for BT than BI. Furthermore, BI steers emitted less methane (CH4) per day; however, when expressing CH4 per unit of DMI, ADG, or as a proportion of gross energy intake, BT steers had a marked advantage. The present study suggests that BT steers exhibited greater growth performance and carcass quality, but observations differed by cattle sub-species in regard to CH4 emissions.
Read the full article in the Journal of Animal Science.
