限制哺乳对安格斯犊牛生长性能、血清免疫与抗氧化指标以及母牛繁殖性能的影响

Effects of Lactation Restriction on Growth Performance,Serum Immune and Antioxidant Indexes of Angus Calves and Reproductive Performance of Cows

本试验旨在研究限制哺乳对安格斯犊牛生长性能、血清免疫与抗氧化指标以及母牛繁殖性能的影响。选择初生重相近、健康的安格斯初生犊牛24头,分为3组,每组8头。对照组随母哺乳,试验组限制哺乳(试验Ⅰ组每日哺乳2次,试验Ⅱ组每日哺乳3次),犊牛10日龄早期补饲,35日龄开始限制哺乳,90日龄断奶试验结束。结果表明:1)与对照组相比,犊牛每日哺乳3次极显著提高了90日龄体重(P<0.01),显著提高了90日龄体长、胸围及61~90日龄平均日干物质采食量(P<0.05)。2)与对照组相比,犊牛每日哺乳3次极显著提高了血清葡萄糖(GLU)含量(P<0.01),极显著降低了血清乳酸脱氢酶(LDH)活性(P<0.01);试验Ⅰ组、试验Ⅱ组血清谷草转氨酶(AST)活性分别较对照组降低24.95%(P>0.05)和42.70%(P<0.05)。3)与对照组相比,犊牛每日哺乳3次极显著提高了血清免疫球蛋白A(IgA)含量(P<0.01),极显著降低了血清白细胞介素-4(IL-4)、白细胞介素-6(IL-6)、白细胞介素-17(IL-17)含量(P<0.01),极显著提高了血清肿瘤坏死因子-α(TNF-α)含量(P<0.01)。4)限制哺乳提高了血清抗氧化水平,总体呈试验Ⅱ组>试验Ⅰ组>对照组的趋势。血清GSH-Px活性各组间差异极显著(P<0.01),血清SOD活性2个试验组均极显著高于对照组(P<0.01),血清MAD含量试验Ⅱ组极显著低于对照组(P<0.01),显著低于试验Ⅰ组(P<0.05)。5)限制哺乳对母牛产后增重无显著影响(P>0.05),但每日哺乳3次母牛产后首次发情时间最短。综上所述,安格斯犊牛35日龄以后每日哺乳3次,其他时间离母,可使机体免疫和抗氧化能力有所提高,促进犊牛生长发育最好,且母牛产后首次发情时间最短。因此,可考虑断奶前逐渐减少犊牛哺乳次数,以进一步提高犊牛饲料利用率、缩短母牛产后发情时间。

The purpose of this experiment was to study the effects of lactation restriction on the growth performance,serum immune and antioxidant indexes of Angus calves and reproductive performance of cows.Twenty-four healthy Angus calves with similar birth weight were selected and divided into 3 groups with 8 calves in each group.The calves in control group were breast-feeding,and those in trial groups were breast-feeding restricted(trial groupⅠbreast-feeding 2 times a day,trial groupⅡbreast-feeding 3 times a day).Early supplementary feeding of calves at 10 days of age,limited breastfeeding at 35 days of age,and weaning at 90 days of age the test was over.The results showed as follows:1)compared with the control group,the calf feeding 3 times a day extremely significantly increased the weight at 90 days of age(P<0.01),and significantly increased the body length,chest circumference at 90 days of age and average daily dry matter intake at 60 to 90 days of age(P<0.05).2)Compared with the control group,the calf breast-feeding 3 times a day extremely significantly increased the serum glucose(GLU)content(P<0.01),and extremely significantly reduced the lactic dehydrogenase(LDH)activity(P<0.01);the aspartate aminotransferase(AST)activity in trial groupsⅠandⅡwere 24.95%(P>0.05)and 42.70%(P<0.05)lower than that of the control group.3)Compared with the control group,the calf breast-feeding 3 times a day extremely significantly increased the serum immunoglobulin A(IgA)content(P<0.01),extremely significantly reduced the serum interleukin-4(IL-4),interleukin-6(IL-6)and interleukin-17(IL-17)contents(P<0.01),and extremely significantly increased the serum tumor necrosis factor-α(TNF-α)content(P<0.01).4)Restriction of breastfeeding increased the serum antioxidant level,showing a trend of trial groupⅡ>trial groupⅠ>control group.The difference of serum glutathione peroxidase(GSH-Px)activity among groups was extremely significant(P<0.01),and the serum superoxide dismutase(SOD)activity in trial groupsⅠandⅡwas extremely significantly higher than that in control group(P<0.01),while the serum malondialdehyde(MDA)content in trial groupⅡwas extremely significantly lower than that in control group(P<0.01),and significantly lower than that in trial groupⅠ(P<0.05).5)Restriction of breastfeeding had no significant effect on postpartum weight gain of cows(P>0.05),but the first estrus time was the shortest after breastfeeding 3 times a day.In summary,Angus calves breastfeed 3 times a day after 35 days of age,at other time separated from the mother,their immunity and antioxidant capacity are improved,which promotes the growth and development of the calves,and the first estrus time after the cow is the shortest.It may be considered to gradually reduce the number of feedings of calves before weaning to further improve the utilization of calves’diet and shorten the time of postpartum estrus for cows.