不同比例全株玉米青贮、谷草和羊草组合饲粮对干奶前期奶牛体况、瘤胃发酵和血液生化指标的影响

旨在研究不同比例谷草和羊草组合饲粮对干奶前期奶牛体况、养分表观消化率、血液指标和瘤胃发酵特性的影响。选择干奶前期荷斯坦奶牛45头,根据胎次、体况评分(BCS)、体质量及预产期接近的原则将奶牛随机分为A、B、C 3组,每组15个重复,每个重复1头牛。全株玉米青贮、谷草和羊草组合比例A、B、C组分别为24∶30∶30,24∶45∶15,24∶60∶0,各组精饲料饲喂量相同。试验期45 d。结果显示:与C组相比,A、B组干物质采食量(DMI)分别提高了7.94%(P>0.05),17.25%(P<0.05),3组的BCS差异不显著(P>0.05)。B组粗蛋白(CP)的表观消化率比A、C组分别提高9.4%(P<0.01)和14.1%(P<0.01)。试验各组粗脂肪(EE)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、钙(Ca)和磷(P)的表观消化率差异不显著(P>0.05)。A、B、C组的β-羟丁酸(BHBA)、尿素氮(BUN)和非酯化脂肪酸(NEFA)差异不显著(P>0.05)。B组的瘦素(LP)、血糖(GLU)、清蛋白(ALB)比C组分别提高了12.11%(P<0.05),22.09%(P<0.05),3.74%(P<0.05),A、B组间无差异(P>0.05)。B组的IgG比A、C组分别提高了9.45%(P<0.05),11.90%(P<0.05),A、C组差异不显著(P>0.05)。各试验组的物种观察指数、辛普森指数、赵氏指数、ACE指数、文库覆盖率差异不显著(P>0.05),A、B组间的香农指数差异显著(P<0.05)。试验组间的拟杆菌门、厚壁菌门、变形菌门丰度差异不显著(P>0.05)。结果表明,干奶前期饲粮中全株玉米青贮、谷草和羊草的比例组合为24∶30∶30时,改善了干奶前期奶牛的DMI、CP消化率、血清葡萄糖和IgG含量,对瘤胃微生物菌群无影响。

Effects of different dietary ratios of whole corn silage,millet straw and Leymus Chinensis on body condition,rumen fermentation and blood biochemical parameters of cows in the early stage of dry period

The experiment was conducted to study the effects of different ratios of whole corn silage,millet straw and Leymus chinensis on nutrient apparent digestibility,blood indices and rumen fermentation characteristics of cows in the early stage of dry period.Forty-five Holstein dry cows were chosen in this experiment according to the same parity and body condition(BCS).The cows were randomly divided into 3 groups(A,B and C) with 14 replicates in each group and 1 cow in each replicate.The combination ratio of whole corn silage,millet straw and Leymus chinensis was 24∶30∶30(group A),24∶45∶15(group B) and 24∶60∶0(group C).The amount of concentrate in each group was the same.The experiment lasted 45 days.The results showed that compared with group C,DMI of group A and B increased by 7.94%(P>0.05) and 17.25%(P<0.05),respectively.There was no significant difference in BCS among the three experimental groups(P>0.05).Compared with group A and C,the CP in group B was increased by 9.4%(P<0.01)and 14.1%(P<0.01),respectively.EE,NDF,ADF,Ca and P was not significantly different among the groups(P>0.05).There were no significant differences in BHBA,BUN,and NEFA among groups A,B,and C(P>0.05).Compared with group C,LP,GLU and ALB in group B were increased by 12.11%(P<0.05),22.09%(P<0.05),3.74%(P<0.05),respectively.There was no difference in LP,GLU and ALB between groups A and B(P>0.05).IgG in group B was 9.45%(P<0.05)and 11.90%(P<0.05)higher than that in group A and C,respectively.There was no significant difference in IgG between group A and C(P>0.05).There was no significant difference in species observation index,Simpson index,Zhao index,ACE index and library coverage among the experimental groups(P>0.05).There was significant difference in Shannon index between groups A and B(P<0.05).There was no significant difference in the abundance of Bacteroides,thick-walled bacteria and Proteobacteria between the experimental groups(P>0.05).In conclusion,the appropriate combination of whole corn silage,millet straw and Leymus chinensis was24∶30∶30,which improved the DMI,CP digestibility,serum glucose and serum IgG content of dry cows,and it had no effect on rumen microflora.