Francis Forest L, Grimes Becca B, Hawkins Dean E, Lust David G, McEvers Trent J, Tennant Travis C, Veneklasen Gregg O, Abraham Jason M, Gleghorn Justin F, Lawrence Ty E
Department of Agricultural Sciences, West Texas A&M University, Canyon, TX 79016, USA.
Timber Creek Veterinary Hospital, Canyon, TX 79015, USA.
Transl Anim Sci. 2024 Aug 24;8:txae126. doi: 10.1093/tas/txae126. eCollection 2024.
The cloning of beef carcasses that grade United States Department of Agriculture (USDA) Prime-yield grade (YG) 1 (P1) has produced a sire that ranked well against high-performing bulls from multiple breeds. An F1 (P1 × P1 - first generation offspring) sire would ideally outperform its high-performing parents. A terminal sire study was conducted comparing progeny of an F1 (P1 × P1) sire (AxG1) against progeny (heifers and steers) of four high-performing sires of varying breeds {P1 (ALPHA); Angus; Simmental; Angus × Simmental}. Production traits included morbidity and mortality frequencies, weaning weight, feedlot arrival weight, and days on feed; carcass traits included frequency of abscessed liver and lung health, quality grade and YG parameters, total carcass value (US$), and carcass value per hundredweight (CWT [45.4 kg]; US$). A completely randomized experimental design was used; data were analyzed using a mixed model with a fixed effect of sire and random effects of harvest date, sex, and pen. AxG1 sired heifers had the highest ( < 0.01) marbling score, the highest ( < 0.01) carcass value per CWT, and numerically had the lowest calculated YG and highest frequency of YG one carcass. Steers sired by AxG1 had the least ( = 0.05) backfat, lowest ( < 0.01) calculated YG, highest ( < 0.01) marbling score, highest ( < 0.01) frequency of USDA Prime carcasses, the greatest ( < 0.03) total carcass value, and greatest ( < 0.01) carcass value per CWT. Collectively, AxG1 steer and heifer carcasses exhibited the least 12th rib fat thickness and lowest USDA YG in addition to the largest longissimus muscle area, highest marbling score, and greatest frequency of USDA Prime. These data suggest that AxG1 performed comparably to other high-performing industry terminal sires in carcass quality and YG outcomes.
克隆出的牛肉胴体等级达到美国农业部（USDA）特优级产量等级（YG）1（P1），由此培育出的一头种公牛与多个品种的高性能公牛相比表现出色。理想情况下，一头F1（P1×P1——第一代后代）种公牛的性能应超过其高性能的双亲。开展了一项终端父本研究，将一头F1（P1×P1）种公牛（AxG1）的后代与四个不同品种的高性能种公牛{P1（阿尔法）；安格斯牛；西门塔尔牛；安格斯×西门塔尔杂交牛}的后代（小母牛和阉牛）进行比较。生产性状包括发病率和死亡率、断奶体重、饲养场入场体重以及育肥天数；胴体性状包括肝脏脓肿频率和肺部健康状况、质量等级和YG参数、胴体总价值（美元）以及每英担（CWT[45.4千克]；美元）的胴体价值。采用完全随机试验设计；数据使用混合模型进行分析，其中种公牛为固定效应，收获日期、性别和栏位为随机效应。AxG1所生小母牛的大理石花纹评分最高（P<0.01），每CWT的胴体价值最高（P<0.01），并且在数值上计算得出的YG最低，YG为1级的胴体频率最高。AxG1所生阉牛的背膘最薄（P=0.05），计算得出的YG最低（P<0.01），大理石花纹评分最高（P<0.01），USDA特优级胴体的频率最高（P<0.01），胴体总价值最大（P<0.03），每CWT的胴体价值最大（P<0.01）。总体而言，AxG1阉牛和小母牛的胴体除了具有最大的背最长肌面积、最高的大理石花纹评分和最高的USDA特优级频率外，第12肋脂肪厚度最薄，USDA YG最低。这些数据表明，AxG1在胴体质量和YG结果方面与其他高性能的行业终端种公牛表现相当。
