摘要
本试验旨在研究饲养密度对2～4月龄断奶羔羊生长性能及血清激素、生化和抗氧化指标的影响.选取2月龄、平均体重为(14.86±1.24)kg的健康澳洲白公羔72只,随机分为3组,分别命名为试验Ⅰ组、试验Ⅱ组和试验Ⅲ组,每组3个重复,每个重复8只羊.试验Ⅰ组、试验Ⅱ组和试验Ⅲ组的饲养密度分别为0.875、0.625和0.375 m2/只.试验期60 d.结果表明:1)随着饲养密度的增大,各组羔羊终末体重(FW)、平均日采食量(ADFI)、平均日增重(ADG)和料重比(F/G)均没有显著差异(P＞0.05),但试验Ⅲ组、试验Ⅱ组的F/G较试验Ⅰ组有降低的趋势(P=0.091).2)试验第40天,试验Ⅲ组羔羊血清中甲状腺素(T4)浓度显著高于试验Ⅱ组、试验Ⅰ组(p＜0.05);试验Ⅲ组羔羊血清中三碘甲状腺原氨酸(T3)浓度显著高于试验Ⅰ组(P＜0.05).试验第60天,试验Ⅲ组羔羊血清中T3浓度显著高于试验Ⅱ组、试验Ⅰ组(P＜0.05);试验Ⅲ组、试验Ⅱ组羔羊血清中生长激素(GH)和胰岛素样生长因子-Ⅰ(IGF-Ⅰ)浓度均显著低于试验Ⅰ组(P＜0.05).3)试验第40天,试验Ⅲ组羔羊血清中球蛋白(GLB)、葡萄糖(GLU)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)浓度均显著高于试验Ⅱ组、试验Ⅰ组(P＜0.05);试验Ⅲ组羔羊血清中总蛋白(TP)浓度较试验Ⅱ组、试验Ⅰ组有升高的趋势(P=0.086).试验第60天,试验Ⅲ组羔羊血清中GLB浓度显著高于试验Ⅰ组(P＜0.05);试验Ⅲ组羔羊血清中TC、HDL和LDL浓度均显著高于试验Ⅱ组、试验Ⅰ组(P＜0.05).4)试验第40天,各组羔羊血清中抗氧化指标没有显著差异(P＞0.05).试验第60天,试验Ⅲ组羔羊血清中总抗氧化能力(T-AOC)与过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性均显著低于试验Ⅱ组、试验Ⅰ组(P＜0.05),血清中丙二醛(MDA)含量显著高于试验Ⅱ组、试验Ⅰ组(P＜0.05).由此可见,试验Ⅲ组羔羊有应激反应发生.从经济效益和动物福利的角度考虑,建议2～4月龄断奶羔羊的饲养密度为0.625 m2/只,羊舍栏位宽度可以设置成2 m.
Abstract
This study aimed to examine the effects of stocking density on the growth performance and serum hormonal,biochemical and antioxidant indicators of weaned lambs aged 2 to 4 months.A total of 72 healthy Australian white male lambs with an average weight of(14.86±1.24)kg were randomly divided into three groups,namely,experimental groups Ⅰ,Ⅱ and Ⅲ,with each group having three replicates and eight sheep in each replicate.The stocking densities in experimental groups Ⅰ,Ⅱ and Ⅲ were 0.875,0.625 and 0.375 m2/lamb,respectively.The experimental period lasted for 60 days.The results showed as follows:1)there were no significant differences in final body weight(FW),average daily feed intake(ADFI),average daily gain(ADG)and feed/gain(F/G)of lamb among the groups(P＞0.05).However,the F/G of lamb in the experimental group Ⅲ and the experimental group Ⅱ showed a decreasing trend compared with the experi-mental group Ⅰ(P=0.091).2)On the 40th day of the experiment,the concentration of thyroxine(T4)in serum of lambs in the experimental group m was significantly higher than that in the experimental group Ⅱ the and experimental group Ⅰ(P＜0.05);additionally,the concentration of triiodothyronine(T3)in serum of lamb in the experimental group Ⅲ was significantly higher than that in the experimental group Ⅰ(P＜0.05).On the 60th day of the experiment,the concentration of T3 in serum of lamb in the experimental group Ⅲ was significantly higher than that in the experimental group Ⅱ and the experimental group Ⅰ(P＜0.05);further-more,the serum growth hormone(GH)and insulin-like growth factor-Ⅰ(IGF-Ⅰ)concentrations of lamb in the experimental group Ⅲ and the experimental group Ⅱ were significantly lower than those in the experimental group Ⅰ(P＜0.05).3)On the 40th day of the experiment,the serum globulin(GLB),glucose(GLU),tri-glyceride(TG),total cholesterol(TC),high density lipoprotein(HDL)and low density lipoprotein(LDL)concentrations of lambs in the experimental group Ⅲ were significantly higher than those in the experiment group Ⅱ and the experimental group Ⅰ(P＜0.05);moreover,there was an increasing trend in the concentra-tion of total protein(TP)in serum of lamb in the experimental group Ⅲ compared with that in the experimen-tal group Ⅱ and the experimental group Ⅰ(P=0.086).On the 60th day of the experiment,the concentration of serum GLB of lamb in the experimental group Ⅲ was significantly higher than that in the experimental groupⅠ(P＜0.05);furthermore,the concentrations of TC,HDL and LDL in serum of lambs in the experimental group Ⅲ were significantly higher than those in the experimental group Ⅱ and the experimental group Ⅰ(P＜0.05).On the 40th day of the experiment,there was no significant change in serum antioxidant indicators of lamb among the groups(P＞0.05).However,on the 60th day of the experiment,the total antioxidant capacity(T-AOC)and the activities of catalase(CAT),glutathione peroxidase(GSH-Px)and superoxide dismutase(SOD)in serum of lamb in the experimental group Ⅲ were significantly lower than those in the experimental group Ⅱ and the experimental group Ⅰ(P＜0.05),while the serum malondialdehyde(MDA)content was significantly higher than that of the experimental group Ⅱ and the experimental group Ⅰ(P＜0.05).Based on the results,the lambs in the experimental group Ⅲ exhibit a stress reaction.Therefore,from the standpoint of animal welfare and economic benefits,it is recommended to provide 0.625 m2 per lamb for stocking density of 2-to 4-month-old weaned lambs,and the width of the sheep pens should be set to 2 meters.[Chinese Journal of Animal Nutrition,2024,36(7):4544-4553]
基金项目
农业农村部规划设计研究院"双化"项目(SH202103)
设施养殖工艺与装备科技创新团队项目(CHXTY-2021-07)
内蒙古重点研发与成果转化计划(2023YFDZ0082)
维普
万方数据