哺乳犊牛的饲喂程序对后续繁殖性能和血浆代谢物的影响

Effects of feeding procedure on subsequent reproductive performance and plasma metabolites of lactating calves

文章旨在评估哺乳期犊牛饲喂程序对其后续繁殖性能及各阶段血浆代谢物浓度的影响。试验将体重接近的72头刚出生的犊牛随机分为3组,每组24头。犊牛出生后3 d开始饲喂代乳料(200 g/L),T1和T2组犊牛在第3天每天饲喂3 L代乳料,之后逐渐增加饲喂量,在20 d时达到9 L/d,之后以9 L/d持续到90 d(T1组)和60 d(T2组),T3组犊牛在9~30 d时每天饲喂6 L代乳料,在31~70 d每天饲喂7 L代乳料。结果:T1和T2组90 d肉牛的代乳料摄入量较T3组显著提高14.62%和10.66%(P<0.05),而T2组300 d肉牛的体高较T1和T3组分别显著提高4.18%和3.75%(P<0.05)。T3组母牛的第一次授精时间显著高于T1和T2组(P<0.05),而T2和T3组母牛11~13月龄妊娠率及1次人工授精受孕率显著高于T1组(P<0.05)。T3组60 d牛血浆葡萄糖、磷浓度及180 d IGF-1浓度均显著高于T1组(P<0.05)。在60 d时,T2和T3组血浆胆固醇和钙浓度显著高于T1组(P<0.05),T1和T2组血浆非酯化脂肪酸浓度显著高于T3组(P<0.05)。结论:在本试验条件下,断奶后3 d的犊牛以最高7 L/d饲喂代乳料是最合适的饲喂程序,而以最高9 L/d饲喂代乳料会降低人工授精时母牛的受孕率。

The aim of this study was to evaluate the effects of feeding program of lactating calves on reproductive performance and plasma metabolite concentrations of subsequent cows at different stages.Seventy-two newborn calves with similar body weight were randomly divided into 3 groups with 24 calves per group.Calves were first fed with milk resubstitute(200 g/L)on day 3 after birth.In groups T1 T1 and T2,calves were fed with 3 L milk resubstitute every day on day 3,and then the feeding amount was gradually increased to 9 L/d on day 20,and then continued to be fed with 9 L/d for 60 d(T1)and 40 d(T2),respectively.In group T3,calves were fed 6 L milk replaceable per day from 9~30 days and 7 L milk replaceable per day from 31~70 days.Results:Compared with T3 group,dairy substitute intake of beef cattle at 90 days in T1 and T2 groups was significantly increased by 14.62%and 10.66%(P<0.05),while body height of beef cattle at 300 days in T2 group was significantly increased by 4.18%and 3.75%(P<0.05),respectively.The time of first insemination in T3 group was significantly higher than that in T1 and T2 groups(P<0.05),while the pregnancy rate at 11~13 months and the pregnancy rate after one artificial insemination in T2 and T3 groups were significantly higher than that in T1 group(P<0.05).Plasma glucose and phosphorus concentrations at 60 days and IGF-1 concentrations at 180 days in T3 group were significantly higher than those in T1 group(P<0.05).On day 60,plasma cholesterol and calcium concentrations in T2 and T3 groups were significantly higher than those in T1 group(P<0.05),while plasma non-esterified fatty acid concentrations in T1 and T2 groups were significantly higher than those in T3 group(P<0.05).Conclusion:Under the experimental conditions of this study,7 L/d milk replacer is the most suitable feeding procedure for calves at 3 days after weaning,and 9 L/d milk replacer will reduce the pregnancy rate of cows during artificial insemination.