| This experiment was conducted to study the effects of supplementation of different doses of mannan oligosaccharides on nutrient digestibility,milk production,milk and colostrum composition,rumen fermentation patterns of Holstein dairy cows during perinatal period.Sixty Holstein dairy cows with similar parity,body condition,for adaptation and the mannan oligosaccharides were supplemented from 21 d before expected calving date to 21 d postpartum were selected and divided into four groups according to the complete randomized design,15 cows in each group were fed with basic diet in the control group(group C),and 5,10,15 g/d mannose oligosaccharides were added to the basic diet in the low,medium and high dose groups(group L,M,H).The results showed that:1)The digestibility of Neutral detergent fiber(NDF),crude fat(EE)and dry matter(DM)increased significantly(P<0.05)with the increase of mannose oligosaccharides dose in postpartum period,among which the digestibility of NDF increased the most;the digestibility of ADF increased first and then decreased at both 7 and 14 days postpartum(P<0.05),reached the maximum in group M,and increased significantly at 21 days postpartum(P<0.05);the digestibility of CP did not differ at both 7 days postpartum,but it increased first and then decreased at 14 and 21 days postpartum(P<0.05),reaching the maximum in group M.2)With the increase of mannose oligosaccharide dose,the milk yield of each group increased in turn on the 7th,14th and 21st day(P<0.05);the somatic cells of each group decreased in turn on the 7th and 14th day after delivery(P<0.05),but there was no significant difference in the number of somatic cells in each group on the 21st day after delivery;the 4%Milk Fat Correction Milk(4%FCM)production of each group increased significantly on the 7th and 14th day postpartum(P<0.05),and the FCM production of each group increased significantly on the 21st day postpartum(P<0.01).Feed conversion efficiency increased significantly(P<0.05).3)With the increase of mannose oligosaccharides,there were no significant changes in milk fat percentage,milk protein rate,lactose rate,urea nitrogen and F/P in each group,but the milk fat yield and milk protein yield in each group increased significantly at 7 days postpartum(P<0.05);at 14 days postpartum,the milk fat yield in each group increased first and then decreased,reaching the maximum value in M group(P<0.05),and the milk protein yield increased in turn(P<0.05).At 21 days postpartum,the milk fat in each group increased in turn(P<0.01),but the milk protein yield had no significant difference(P>0.05).4)With the increase of mannose oligosaccharide,the content of microbial protein(MCP)and the contents of acetic acid,butyric acid,valeric acid,TVFA and the ratio of acetate to Propionatein rumen fluid of your dairy cows increased 21 days after delivery.The contents of MCP,acetic acid and isobutyric acid in rumen fluid of group H were significantly increased than those of the other three groups(P<0.01),and the content of propionic acid was significantly increased than that of group C(P<0.05),but there was no significant difference with those of group L and M.The lowest difference was found in group C,with the lowest level of valeric acid in group L,which was significantly decreased than that in group H(P<0.01)and significantly decreased than that in group M(P<0.05);TVFA in group H was significantly increased than that in group C and group L(P<0.01),significantly increased than that in group M(P<0.05);and the ratio of ethylene to propylene in group H was significantly increased than that in the other three groups(P<0.05).5)Colostrum yield and concentration of interlenkin-1(IL-1),interlenkin-6(IL-6)and immunoylobulin-G(IgG)in colostrum increased with the increase of mannose-oligosaccharide dosage.Colostrum yield and concentration of IL-6 in group H and M were significantly increased than those in group C and M(P<0.05),while the concentration of IL-1 was significantly increased than that in group C(P<0.05),but there was no significant difference with that in group M.The concentration of IgG increased with the increase of mannose-oligosaccharide dosage(P<0.01).In colostrum,immunoylobulin-A(IgA)and immunoylobulin-M(IgM)increased first and then decreased,reaching the maximum value in L group,and the difference of IgM reached a significant level,which was significantly increased than that in H group(P<0.05).In conclusion,mannose oligosaccharide can improve milk production,feed efficiency,immune performanc and fat and protein production of milk,and increase the digestibility of NDF,ADF,CP and EE in dairy cows.The best supplementation dose was 10～15 g/d in current study. |
PDF Full Text Request