Stocker and Feedlot Performance and Carcass Characteristics of Purebred Angus and Romosinuano Steers

Stacker and feedlot performance of purebred Angus (n = 61) and Romosinuano (n = 99) steers were compared over two 11-mo production cycles (2000 through 2002). Calves were born in the winter (January through March), reared in a subtropical environment (central Florida), weaned in the fall, and shipped 1,900 km for growth and finishing in a more temperate environment (central Oklahoma). Calves were managed as a single group each year during the winter (125 d) and spring (84 d) stocker phases. Annual cool season grasses (wheat Triticum aestivum and Bromus sp.) were the primary forage resource for the stocker phase. Angus and Romosinuano calves had similar BW upon arrival (193 ± 3.5 kg). During the winter stocker period, Romosinuano calves gained less (P < 0.01) BW than Angus steers (76 vs. 103 kg) but gained similar (P = 0.74) amounts during the spring stocker period (42 kg). As a result, overall stocker BW gains were less (P < 0.01) during the stocker phase for Romosinuano steers as compared with Angus steers (118 vs. 145 kg). Each year at the end of the stocker phase, 18 Angus calves and 18 Romosinuano calves were blocked by breed and randomly assigned to 1 of 6 pens (2.6 m2 of floor space per steer) to measure individual feed intake. Romosinuano steers ate less feed (P < 0.05) and tended (P = 0.13) to have less ADG than Angus steers, but feed efficiency was similar (P = 0.33). Angus steers were heavier (P < 0.05) at the start of the finishing period and produced carcasses that had greater (P < 0.01) marbling scores, yield grades, and quality scores than Romosinuano steers. Under a temperate production environment, purebred Romonsinuano steers had less ADG during the winter stocker period, but produce leaner carcasses than purebred Angus steers during the finishing phase.