Abstract
The objectives of this study were to assess influences of creep feeding, preweaning growth-promoting implants, and breed type on feedlot and carcass traits of 80 steer sired by Brahman and Romana Red bulls. Creep treatments were: no creep (NC); short-term creep (SC) fed from 146 to 210 days of age; and long-term creep (LC) fed from 56 to 210 days of age. Alternate steers within creep treatment and breed type were implanted twice with 36 mg zeranol at an average of 56 and 146 day of age. All steers were slaughtered at an estimated fat thickness of 1 cm. The SC and LC steers were heavier (P < 0.03) at the beginning of the feedlot phase, but NC steers had more total feedlot gain (P < 0.04). Steer implanted with zeranol before weaning had heavier (P < 0.05) initial and final feedlot weights, and greater (P < 0.09) carcass weight, but a lower (P < 0.06) percentage graded USDA Choice. Brahman sired steers required 22 days less (P < 0.01) to finish in the feedlot than Romana Red sired steers ; however, Romana Red sired steers exhibited a greater (P < 0.10) response to zeranol implants for feedlot gain and carcass cutability traits. This study suggest that variation does exist among Bos indicus beef breeds in association with preweaning management practices for feedlot and carcass performance.
