Abstract The objectives were to investigate feedlot performance and carcass traits of four different cattle types: Simmental×Angus (SMAN) steers (n = 42), SMAN×Holstein (HO) heifers (n = 38) and steers (n = 39), and HO steers (n = 42). The SMAN×HO and HO cattle were contemporaries sourced from the same dairy. After a 21-d acclimation period, cattle were randomly allocated to seven pens per cattle type. Body weight (BW), average daily gain (ADG), and gain to feed were determined every 28 d, and dry matter intake (DMI) was determined every 14 d. Initial BW (312 ± 26.3 kg) was included as a covariate in statistical analyses. Harvest was scheduled when cattle types reached an average empty body fat (EBF) of 32.5% predicted by ultrasound. Carcass data were collected following a 48-h chill. Final live BW was different among cattle types, with the SMAN×HO heifers and steers being lighter compared with the SMAN and HO steers (P 0.01). The ADG of SMAN×HO steers was 4.9% greater than SMAN steers and 7.4% greater than SMAN×HO heifers (P 0.01), but similar to HO steers (P = 0.68). Steers of all cattle types had similar DMI (P 0.91), which was greater than the DMI of SMAN×HO heifers (P 0.01). The SMAN×HO heifers and steers were 6.5% more feed efficient than HO steers and 10% more feed efficient than SMAN steers (P 0.01). Liver abscess incidence was greatest for the HO steers, followed by SMAN×HO heifers (P 0.01), while no liver abscesses were observed in SMAN and SMAN×HO steers. Dressing percentage was greatest (P 0.01) for SMAN steers compared with other cattle types, with SMAN×HO steers being greater (P 0.01) than HO steers and SMAN×HO heifers. The SMAN carcasses had greater backfat thickness compared with SMAN×HO heifer and HO steer carcasses (P 0.01). The SMAN×HO heifer and steer carcasses had 0.49 cm and 0.66 cm more backfat thickness, respectively, than the HO carcasses (P 0.01). Longissimus muscle area was 13% larger for the SMAN carcasses compared with the other cattle types (P 0.01). Compared with the HO carcasses, the SMAN×HO heifer carcasses had a 6.3% smaller longissimus muscle area (P 0.01). The SMAN and SMAN×HO steer carcasses had greater carcass empty body fat than the SMAN×HO heifer and HO steer carcasses (P 0.01), and all cattle types were within 1.5% of the desired empty body fat. Calculated USDA Yield Grade, marbling score, and USDA Quality Grade were similar among cattle types (P 0.18). Overall, these results demonstrate how SMAN×HO cattle compare with their SMAN and HO contemporaries in feedlot performance and carcass traits.
Pimentel-Concepción et al. (Wed,) studied this question.