叶酸和甜菜碱对围产期奶牛泌乳性能、乳脂肪酸组成、养分消化和瘤胃发酵的影响

Effects of Folic Acid and Betaine on Lactation Performance,Milk Fatty Acid Composition,Nutrient Digestion and Rumen Fermentation of Dairy Cows during Perinatal Period

本试验旨在研究叶酸(FA)和甜菜碱(BT)对围产期奶牛泌乳性能、乳脂肪酸组成、养分消化和瘤胃发酵的影响。选取预产日期、胎次、体重和上一泌乳期平均产奶量相近的围产期荷斯坦奶牛40头,随机分为4组,每组10头牛。对照组饲喂基础饲粮,FA组、BT组和FA+BT组分别在基础饲粮中添加135 mg/d的FA、100 g/d的BT和135 mg/d的FA+100 g/d的BT。预试期10 d,正试期42 d。结果表明:1)FA组和FA+BT组的实际乳、4%乳脂校正乳、乳脂肪、乳蛋白质产量以及乳脂率和饲料效率(FE)显著高于对照组(P<0.05)。BT组的4%乳脂校正乳、乳脂肪、乳蛋白质产量以及乳脂率和FE显著高于对照组(P<0.05)。2)FA组乳脂肪中葵酸(C10∶0)、月桂酸(C12∶0)、肉豆蔻酸(C14∶0)、棕榈一稀酸(C16∶1)、亚麻酸(C18∶3)和总4~15碳脂肪酸含量显著高于对照组(P<0.05),硬脂酸(C18∶0)含量显著低于对照组(P<0.05)。BT组和FA+BT组乳脂肪中C10∶0、C12∶0、C14∶0、C16∶1、亚油酸(C18∶2)、C18∶3和总4~15碳脂肪酸含量显著高于对照组(P<0.05),C18∶0和总>16碳脂肪酸含量显著低于对照组(P<0.05)。3)FA组、BT组和FA+BT组的干物质(DM)、有机物(OM)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)表观消化率显著高于对照组(P<0.05)。4)FA组、BT组和FA+BT组的瘤胃总挥发性脂肪酸(TVFA)、乙酸和丁酸含量及乙酸/丙酸显著高于对照组(P<0.05)。由此可见,围产期奶牛饲粮中添加FA和BT能改善泌乳性能和养分消化,而且FA和BT共同添加对改善泌乳性能比单独添加更有效。

This experiment was conducted to study the effects of folic acid(FA)and betaine(BT)on lactation performance,milk fatty acid composition,nutrient digestion and rumen fermentation of dairy cows during perinatal period.Forty Holstein dairy cows during perinatal period with similar expected delivery date,parity,body weight and average milk yield during the previous lactation period were randomly divided into 4 groups with 10 cows in each group.Cows in the control group were fed a basal diet,and others in FA,BT and FA+BT groups were fed basal diets supplemented with 135 mg/d FA,100 g/d BT and 135 mg/d FA+100 g/d BT,respectively.The pre-experimental period lasted for 10 days,and the experimental period lasted for 42 days.The results showed as follows:1)the actual milk,4%fat-corrected milk,milk fat and milk protein yields,and milk fat rate,feed efficiency(FE)of FA and FA+BT groups were significantly higher than those of the control group(P<0.05).The 4%fat-corrected milk,milk fat and milk protein yields,and milk fat rate,FE of BT group were significantly higher than those of the control group(P<0.05).2)The contents of C10∶0,C12∶0,C14∶0,C16∶1,C18∶3 and total 4 to 15 carbon fatty acid in milk fat of FA group were significantly higher than those of the control group(P<0.05),and the C18∶0 content was significantly lower than that of the control group(P<0.05).The contents of C10∶0,C12∶0,C14∶0,C16∶1,C18∶2,C18∶3 and total 4 to 15 carbon fatty acid in milk fat of BT and FA+BT groups were significantly higher than those of the control group(P<0.05),and the C18:0 and total>16 carbon fatty acid contents were significantly lower than those of the control group(P<0.05).3)The apparent digestibilities of dry matter(DM),organic matter(OM),neutral detergent fiber(NDF)and acid detergent fiber(ADF)of FA,BT and FA+BT groups were significantly higher than those of the control group(P<0.05).4)The rumen total volatile fatty acids(TVFA),acetate and butyrate contents and the ratio of acetate to propionate of FA,BT and FA+BT groups were significantly higher than those of the control group(P<0.05).In conclusion,the supplementation of FA and BT for dairy cows during perinatal period can improve the lactation performance and nutrient digestion,and the combined supplementation of FA and BT is more effective in improving lactation performance compared with than it addition alone.