摘要
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 (p < 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 (p < 0.02) with an increase in DMI and intake rate with increasing cow age. Milk production displayed a cow age × RFI interaction (p < 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 (p ≥ 0.16) or cow age × RFI interaction (p ≥ 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.
摘要译文
我们评估了两次生产后干物质摄入（DMI）的断奶后剩余饲料摄入（RFI）分类和牛时代。五十九个非哺乳，怀孕，（研究1）和五十四个哺乳，非怀孕（研究2）商业黑色安群牛牛被年龄和RFI分组。自由选择，干草颗粒在Growsafe饲养系统中喂食。在研究1中，牛DMI（kg / d）和进气率（g / min）显示牛年龄效应（p <0.01），随着DMI的增加和随着牛年龄的增长而增加。在研究2中，牛DMI（kg / d）和进气率（g / min）显示牛年龄效应（p <0.02），随着DMI和增加牛年龄的进气率增加。牛奶生产显示了牛年龄×RFI互动（P <0.01），其中5-6岁和8-9岁的低RFI奶牛比高RFI奶牛产生更多的牛奶。对于研究，摄入和摄入行为不受RFI（P≥0.16）或牛年龄×RFI相互作用的影响（P≥0.21）。总之，小母牛的断奶后RFI对牛肉DMI或进气行为的影响最小，但是，在牛奶生产中观察到一些差异。
Cory T. Parsons[ 1;[*]; Julia M. Dafoe[ 1]; Samuel A. Wyffels[ 1]; Timothy DelCurto[ 2];Darrin L. Boss[ 1]. Influence of Residual Feed Intake and Cow Age on Dry Matter Intake Post-Weaning and Peak Lactation of Black Angus Cows[J]. Animals, 2021,11(6): 1822