Improved growth performance and meat tenderness in jersey steers weaned at 60 days and fed a high-energy forage-free diets

Abstract

The performance, carcass characteristics, and meat quality of Jersey male calves in feedlots were evaluated to determine the optimal feeding program and weaning age for improved growth performance and meat quality. Jersey male calves were paired according to birth and weaned at either 30 or 60 days of age. They were then assigned to one of two feeding groups, both receiving high-energy, isonitrogenous total mixed rations (TMR): a high-grain diet containing 12% forage and 47 % neutral detergent fiber (NDF), or a forage-free diet with 0% forage and 17% NDF. Average Daily Gain (ADG) was evaluated for 265 days after TMR adaptation. All data were analyzed using a completely randomized design in a 2 × 2 factorial arrangement, evaluating two main effects and their interaction. ADG was higher when steers were weaned later (0.923 vs. 0.829 kg/d, P < 0.05). Dry matter intake was higher in steers fed the high-grain diet compared to those fed the forage-free diet (3.21 vs. 2.71% BW, P < 0.05). Feed efficiency was higher in calves weaned at 30 days and fed the forage-free diet (0.27 vs. 0.21 kg/kg, P < 0.05). Tenderness of the Longissimus dorsi muscle, measured after 24 h at 2 °C using Warner–Bratzler shear force, tended to be improved in calves weaned at 60 days and fed the forage-free diet (3.91 vs. 4.27 kg, P < 0.10), as well as a trend for increased backfat thickness in calves weaned at 30 days and fed the forage-free diet (4.2 vs. 3.5 mm, P < 0.10). No significant effects of weaning age or diet were observed on dressing percentage, color parameters, marbling, cooking loss, or LMA (P > 0.10). Rump steak weight was significantly reduced in steers weaned at 30 days and fed a forage-free diet (1.606 vs 1.768 kg, P < 0.05), whereas no effect was observed in steers weaned at 60 days. In conclusion, male Jersey calves weaned at 60 days achieved average daily gains exceeding 0.900 kg, showed greater feed efficiency, and tended to produce more tender meat when fed a forage-free diet, which may result in improved overall meat quality.