Parsons Cory T, Dafoe Julia M, Wyffels Samuel A, DelCurto Timothy, Boss Darrin L
Northern Agricultural Research Center, Montana State University, Havre, MT 59501, USA.
Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717, USA.
Animals (Basel). 2021 Jun 18;11(6):1822. doi: 10.3390/ani11061822.
We evaluated heifer post-weaning residual feed intake (RFI) classification and cow age on dry matter intake (DMI) at two stages of production. Fifty-nine non-lactating, pregnant, (Study 1) and fifty-four lactating, non-pregnant (Study 2) commercial black Angus beef cows were grouped by age and RFI. Free-choice, hay pellets were fed in a GrowSafe feeding system. In Study 1, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect ( < 0.01) with an increase in DMI and intake rate with increasing cow age. In Study 2, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect ( < 0.02) with an increase in DMI and intake rate with increasing cow age. Milk production displayed a cow age × RFI interaction ( < 0.01) where both 5-6-year-old and 8-9-year-old low RFI cows produced more milk than high RFI cows. For both studies, intake and intake behavior were not influenced by RFI ( ≥ 0.16) or cow age × RFI interaction ( ≥ 0.21). In summary, heifer's post-weaning RFI had minimal effects on beef cattle DMI or intake behavior, however, some differences were observed in milk production.
我们评估了小母牛断奶后剩余采食量（RFI）分类和奶牛年龄对两个生产阶段干物质采食量（DMI）的影响。59头非泌乳、怀孕的（研究1）和54头泌乳、未怀孕的（研究2）商业黑安格斯肉牛按年龄和RFI分组。在GrowSafe饲喂系统中自由采食干草颗粒。在研究1中，奶牛的DMI（kg/d）和采食率（g/min）表现出奶牛年龄效应（P<0.01），随着奶牛年龄的增加，DMI和采食率升高。在研究2中，奶牛的DMI（kg/d）和采食率（g/min）表现出奶牛年龄效应（P<0.02），随着奶牛年龄的增加，DMI和采食率升高。产奶量表现出奶牛年龄×RFI交互作用（P<0.01），5至6岁和8至9岁的低RFI奶牛产奶量均高于高RFI奶牛。对于两项研究，采食量和采食行为均不受RFI（P≥0.16）或奶牛年龄×RFI交互作用（P≥0.21）的影响。总之，小母牛断奶后的RFI对肉牛的DMI或采食行为影响极小，然而产奶量存在一些差异。
