Effects of early or conventional weaning on beef cow and calf performance in pasture or drylot environments
Kansas Agricultural Experiment Station Research Reports(2022)
摘要
Performance of cows and calves during 63-d early or conventional weaning periods was evaluated. Spring-calving beef cows (n = 167) of similar age, body condition score (BCS), and body weight (BW = 599 +/- 54.5 kg), and their calves (initial BW = 204 +/- 26.7 kg; 153 +/- 15 d of age) were assigned randomly to 1 of 4 weaning treatments: weaning at 153 d of age followed by 56 days of limit feeding in confinement (E-D), confinement of cow and calf for a 56-d period of limit feeding followed by weaning at 209 d of age (C-D), weaning at 153 d of age followed by a 56-d grazing period (E-P), and a 56-d grazing period for both cow and calf followed by weaning at 209 d of age (C-P). Cows and calves assigned to pasture treatments grazed native range pastures without supplement. Cows and calves assigned to drylot treatments were fed complete diets. Calves assigned to E-D were fed a concentrate-based diet at 2.5% of BW, whereas cows assigned to E-D were fed a forage-based diet at 1.6% of BW. Cows assigned to C-D were offered the diet fed to E-D cows at 2.0% of BW. Calf average daily gain (ADG) was influenced by diet and weaning treatments (diet x weaning, P <= 0.03). Cows and calves assigned to all treatments were limit fed common diets for 7 d at the end of our study to equalize gut fill. In general, calves managed in confinement and fed concentrate-based diets (i.e., E-D and C-D) had greater ADG than non-supplemented calves maintained on pasture (i.e., E-P and C-P). Cow BW and BCS change (days 0 to 63) were influenced by both diet and weaning status (P <= 0.05). Non-lactating cows maintained on pasture had lesser BW loss than other treatments, whereas non-lactating cows fed in confinement had lesser BCS on day 63 and greater BCS loss from days 0 to 63 than other treatments. Conversely, rump-fat depth on day 63 was greater (P < 0.01) for non-lactating cows maintained on pasture than for lactating cows in either pasture or drylot environments. Similarly, change in rump-fat depth was greatest (diet x weaning, P < 0.01) for non-lactating cows on pasture and least for lactating cows in either pasture or drylot environments. Results were interpreted to indicate that early-weaning spared cow BW and rump fat compared to weaning at conventional ages. Performance of cows appeared to be similar when limit-fed under drylot conditions or maintained in a pasture environment. Conversely, calf performance was generally greater in confinement than on pasture.
更多查看译文
关键词
conventional weaning, early weaning, limit-fed
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要