Effect Of Providing Different Levels Vitamin E On Lactation Performance, Immune Function And Reproductive Function Of Dairy Cow In Transition Period

To study the effect of adding different level vitamin E on performance, immune and reproductive function of dairy cow in transition period. 24 head of Holstein cows were selected according to the principle of 2-6 parity , body weight about 550 kg and similar expected calving period and body condition score about 3.5 . The cows were randomly divided into three groups: groupâ… ( basic diet+0.81IUVE/kgBW ) ; groupâ…¡(basic diet + 1.62IUVE/kgBW) ; (basic diet +2.43IUVE /kgBW) . The trial last for 105 days.The results showed that:Dietary different level vitamin E supplementation helped to improve dairy cows performance. The content of vitamin E in milk of dairy cows in groupâ…¢significantly increased at d0 postpartum(P<0.05), d10 postpartum(P<0.05), d20 postpartum(P<0.05), but had no effects on the percentages of milk fat, milk protein milk lactose and total solid material (P>0.05). Milk yields of dairy cows in groupâ…¢increased compared to the other groups (P>0.05). At d10 post-calving , the SCC in milk of dairy cows in groupâ…¢was significantly lower than that of groupâ… . The SCC in milk of cows in groupâ…¢reach the peak at d20 postpartum.After the feeding of vitamin E, the content of cortisol in blood at d7 pre-calving,birth day and d7 post-calving of dairy cows in groupâ…¢were significantly lower than the groupâ… and the groupâ…¡(P<0.05). At d7 post-calving ,the serum immunoglobulin IgA, IgG ,IgM levels of dairy cows in trailâ…¢g roup were significantly higher than groupâ… (P<0.05). At the birth day, the leucocyte count and the percent of lymphocyte in blood of dairy cows in groupâ…¢were both significantly higher then groupâ… and groupâ…¡(P<0.05). the percent of granulocyte in blood of dairy cows in groupâ…¢was significantly lower then groupâ…¡(P<0.05), the percent of monocyte in blood of dairy cows in groupâ…¢was not higher(P>0.05)significantly then groupâ…¡. The results show that: vitamin E has some effect on immunity of dairy cow. Adding 2.43IUVE /kgBW will be effective on improving immune function of dairy cow in transition period. The results indicate that Vitamin E could increase the activity of antioxidative enzyme in serum, and improve the function of antioxidantion of the blood in dairy cow. At d0 postpartum and d7 postpartum, the serum MDA levels of dairy cows in groupâ…¢were significantly lower than groupâ… (P<0.05), . at d7 pretpartum , 0 day postpartum and 7 days postpartum, the serum SOD activity of dairy cows in groupâ…¢were significantly higher than groupâ… (P<0.05).Morbidity of endometrium, ovarian artery, placenta of dairy cows in groupâ…¢were significantly lower than groupâ… and groupâ…¡(P<0.05). The time when cow of groupâ…¢of postpartum appears first oestrus is significantly shorter than that of groupâ… (P<0.05). The percentage of oestrus cows after d60 post-calving of dairy cows in groupâ…¢was less than groupâ… , reduce the number of days with air. Adding different level vitamin E had no effect on the birth weight of calf.In summary,under the present experimental conditions,adding 2.43IU/KgBW vitamin E could improve performance, immune and reproductive function of dairy cow in transition period.