Beef × Dairy vs. Native Beef: Production System and Preweaning Nutrition Effects on Carcass Traits

Abstract This study compared carcass traits across production systems by evaluating Angus × Holstein crossbred calves (AH) against conventional Angus crossbred calves (Native Beef; NB). Angus × Holstein steers and heifers (n = 26 steers, BW = 47.0 ± 4.5; n = 27 heifers, BW = 46.0 ± 3.8) were subjected to two preweaning nutrition programs at the Purina Animal Nutrition Research Facility (Gray Summit, MO). In parallel, NB calves (n = 6 steers; n = 6 heifers) were raised at the OSU South Range Research Station (Stillwater, OK), weaned at 7 months of age, and preconditioned for 60 days. Angus x Holstein calves received either a lesser nutrition preweaning (LPN; 20% fat, 22% protein, 1.2 lb/d powder, 17% CP starter) or greater nutrition preweaning (GNP; 20% fat, 26% protein, 2.5 lb/d powder, 21% CP starter) program for 56 days. Following weaning, all calves were transported to the OSU South Range for acclimation, then grazed winter wheat for 153 days at the USDA-ARS Southern Plains Experimental Range (Ft. Supply, OK). Calves ultimately entered a finishing phase at USDA-ARS Fort Reno (El Reno, OK). Angus x Holstein calves were fed for 191 days, while NB calves were harvested after 100 days on feed. Body weights and carcass measurements were taken on July 9, 2024, September 11, 2024, and October 31, 2024. Scan data were analyzed using repeated measures mixed models with calf ID as a random effect. Carcass traits (harvest) were analyzed with treatment as a fixed effect. Analyses were conducted in R (R Core Team, 2024). Significance was declared at P ≤ 0.05. Time effects were detected for body weight (BW), ribeye area (REA), and rib fat (all P 0.0001). Across all scans, NB calves were heavier with larger REA and greater rib fat than AH calves (P 0.0001), LPN and GPN did not differ from one another. A treatment × sex interaction (P = 0.00088) was observed for intramuscular fat (IMF): NB heifers expressed greater IMF (6.06 ± 0.39%) than LPN (3.53 ± 0.24%) and GNP (3.92 ± 0.26%) heifers (P 0.0001), while steer IMF did not differ (P 0.12). At harvest final BW, hot carcass weight, yield grade, marbling, rib fat, and REA did not differ (P ≥ 0.14), though dressing percentage was greater for NB calves (62.67%) compared to Beef × Dairy (61.94 - 61.93%; P 0.001). Elevated preweaning nutrition did not improve AH outcomes, and carcass traits were similar across breed type except for greater dressing percentage in NB calves. These findings highlight the ability of Angus x Holstein hybrids to produce quality beef, although days on feed must be extended compared to traditionally reared beef calves.