不同淀粉水平日粮中添加酵母培养物对奶牛干物质采食量和瘤胃发酵功能的影响

Effects of yeast culture with dietary different starch levels supplementation on lactation performance and rumen fermentation of dairy cows

文章旨在研究不同淀粉水平日粮中添加酵母培养物对奶牛生产性能和瘤胃发酵功能的影响。试验选择16头荷斯坦奶牛,随机分为4组,每组4个重复,每个重复1头牛。试验日粮采用2×2多因素方差设计,两个淀粉水平(23%和29%),两个酵母培养物水平(0和25 g/d),试验共进行28 d。结果显示:日粮添加酵母培养物后显著提高了产奶量、3.5%标准乳、能量校正奶(P <0.05)。无论是在低或高淀粉水平日粮中添加酵母培养物均显著提高乳脂含量(P <0.05)。高淀粉水平日粮或添加酵母培养物显著提高了乳蛋白含量(P <0.05)。高淀粉水平日粮中添加酵母培养物较对照组显著降低了血浆结合珠蛋白的含量(P <0.05)。高淀粉水平日粮中添加酵母培养无较对照组显著降低了淀粉表观消化率(P <0.05),低淀粉水平日粮组显著提高了乙酸含量(P <0.05)。高淀粉水平日粮组显著提高了瘤胃乳酸含量(P <0.05)。高淀粉水平日粮组较低淀粉水平组显著降低了氮沉积量(P <0.05),添加酵母培养物使氮沉积量显著升高(P <0.05)。高淀粉水平日粮中添加酵母培养物组氮摄入量和乳氮含量最高(P <0.05)。结论 :在本试验条件下,高淀粉水平日粮中添加15 g/d酵母培养物可以降低奶牛代谢紊乱症的发生,提高纤维消化率及微生物蛋白的产量,进而改善泌乳性能。

The aim of this study was to evaluate the effects of yeast culture with dietary different starch levels supplementation on lactation performance and rumen fermentation of dairy cows.Sixty Holstein dairy cows were allotted to 4 groups with 4 replicates of 1 cows.The diets were designed by 2 starch levels(23%and 29%)plus 2 yeast culture(YC)levels(0 and 25 g/d).This experiment last 28 d.Results showed that dietary starch levels did not influence yield of milk(P>0.05,but supplementing YC increased yields of milk,3.5%fat corrected milk,and energy corrected milk(P<0.05).Milk fat yield increased in cows fed YC regardless of levels of dietary starch(P<0.05).Increasing dietary starch reduced ruminal digestibility of NDF,but supplementing YC to the high starch level diet prevented the decline in rumen NDF digestion(P<0.05).The acetic acid contents in the low starch diet showed the lowest(P<0.05).Cows fed high starch diets compared with cows fed low starch diets supplemented with YC increased the lactic acid contents(P<0.05).Cows fed high starch diets has less N retention than cows fed low starch diets,but within high starch diets,those supplemented with YC had the largest productive N yield(P<0.05).In conclusion,supplementing diets of dairy cows with yeast culture minimized the risk of metabolic disorder,particularly when cows were fed a high starch diet,and improved fiber digestion and microbial Nyield.