300 Primeone Sire Comparison on Jersey Dairy Cows

Abstract

Abstract Objective The objective of this study was to compare carcass grading outcomes of progeny from a sire derived via carcass cloning to progeny from a competitive traditional purebred Angus sire. Semen was artificially inseminated into Jersey cows from an F1 sire (AxG1) derived from Prime-yield grade 1 carcass clones and a high-performance purebred Angus sire (Foundation). Calves were born at the dairy, raised in hutches on the dairy, and grown in a separate facility, all in the Texas panhandle. Cattle were later transported to Nebraska for finishing. Both steers and heifers were harvested at a commercial beef processor in Colorado and camera data were collected to assess carcass quality and yield outcomes. Data were analyzed using mixed models; treatment comparisons were tested for significance with α = 0.05. Results In live growth, calves sired by Foundation were heavier (P < 0.01) both when they entered (396.1 vs 383.0 kg) and exited (590.1 vs 568.8 kg) the feedyard. Similarly, calves sired by Foundation had heavier (P < 0.01) hot carcass weights than AxG1 (374.9 vs 361.4 kg). No difference (P ≥ 0.27) was detected between sires for longissimus muscle area (96.6 vs 95.7 cm2) or marbling score (Moderate26 vs Moderate20). AxG1 sired calves had greater (P < 0.01) muscle area per unit of carcass weight (26.7 vs 25.9 cm2/100kg). Calves sired by AxG1 were leaner (P < 0.01) than those sired by Foundation as evidenced by less 12th rib s.c. fat (1.11 vs 1.26 cm) coupled with decreased calculated yield grades (2.34 vs 2.59). Moreover, calculated Empty Body Fat was greater (P < 0.01) for Foundation sired carcasses than those sired by AxG1 (30.0 vs 28.9 %). Foundation sired calves were represented by a greater (P < 0.05) percentage of USDA Prime carcasses (26.32 vs 17.79 %) whereas AxG1 sired calves had a greater (P < 0.05) percentage of USDA Choice carcasses (77.74 vs 69.48 %). AxG1 sired calves were represented by a greater (P = 0.04) percentage of Yield Grade 1 carcasses (27.48 vs 19.25 %). No difference in frequency of Yield Grade 2 (55.40 vs 58.00 %) or 4 (1.41 vs 1.0 %) carcasses was observed between sires. Frequency of Yield Grade 3 carcasses was greater (P < 0.01) for Foundation compared with AxG1 (23.94 vs 13.58 %). Carcass outcomes suggest that progeny sired by Foundation were of slightly higher quality whereas progeny sired by AxG1 were of slightly higher yield.