包被叶酸对羔羊生长性能、养分消化和瘤胃发酵特点的影响

Effects of coated folic acid on growth performance,nutrient digestion and rumen fermentation of lambs

本研究探讨了母羊和断奶后羔羊日粮添加包被叶酸对羔羊生长性能、养分消化和瘤胃发酵特征的影响.从120头母羊[(44.5±5.5)kg]分娩的羔羊中选择平均体重为(16.3±3.82)kg的羔羊86只,根据体重、性别随机分为3(母羊日粮叶酸添加水平0、15和30 mg/kg)×2(羔羊日粮叶酸添加水平0和5 mg/kg)的设计中.结果发现,断奶前羔羊的平均日增重随母羊日粮叶酸添加水平的升高表现为二次曲线升高(P<0.05),而断奶后日粮处理对羔羊干物质摄入量无显著影响(P>0.05).羔羊日粮添加叶酸能显著提高日增重,降低料重比(P<0.05),同时羔羊日粮添加叶酸能显著提高有机物和粗蛋白质表观消化率(P<0.05).母羊日粮添加叶酸能显著降低羔羊瘤胃pH,提高挥发性脂肪酸含量(P<0.05).母羊和羔羊日粮添加叶酸后空肠淀粉酶活性显著提高(P<0.05),而母羊日粮添加叶酸能显著提高十二指肠、空肠和回肠胰蛋白酶、糜蛋白酶和脂肪酶活性(P<0.05).母羊日粮添加叶酸显著提高了羔羊血清葡萄糖、高密度脂蛋白、极低密度脂蛋白和胰岛素样生长因子-1浓度(P<0.05),但羔羊日粮添加叶酸血清胆固醇含量显著降低(P<0.05).结论:在本试验条件下,包被叶酸的适宜添加量为母羊15 mg/kg,羔羊5 mg/kg.

This study investigated the effects of dietary supplementation with folic acid on growth performance,nutrient digestion and rumen fermentation characteristics of ewes and lambs after weaning.A total of 86 lambs with an average body weight of 16.3±3.82kg were selected from 120 ewes(44.5±5.5kg)and randomly assigned to 3(dietary folic acid supplementation level of ewes 0,15 and 30 mg/kg)×2(dietary folic acid supplementation level of lambs 0 and 5 mg/kg)according to body weight and sex.Results:the average daily weight gain of lambs before weaning increased with the increase of folic acid supplementation level in ewe diet(P<0.05),while the dietary treatment after weaning had no significant effect on dry matter intake of lambs(P>0.05).Dietary folic acid supplementation in lambs significantly increased the daily weight gain and decreased the feed-to-weight ratio(P<0.05),while dietary folic acid supplementation in lambs significantly increased the apparent digestibility of organic matter and crude protein(P<0.05).Folic acid supplementation significantly reduced rumen pH and increased volatile fatty acid content in ewes(P<0.05).Folic acid supplementation in ewe and lamb diets significantly increased jejunal amylase activity(P<0.05),while folic acid supplementation in ewe diets significantly increased duodenum,jejunum and ileum trypsin,chymotrypsin and lipase activity(P<0.05).Folic acid supplementation in ewes significantly increased serum glucose,HDL,VLDL and insulin-like growth factor-1 concentrations in lambs(P<0.05),but folic acid supplementation in lambs significantly reduced serum cholesterol(P<0.05).In conclusion,under the conditions of this study,the appropriate amount of folic acid was 15 mg/kg in ewe diet and 5 mg/kg in lamb diet.