Effects Of Different Level Se-Yeast On Anti-oxidation Performance And Immune Performance Of Dairy Cows During The Transition Period

This two experiments were conducted to investigate the effects of diet supplementation with Se-yeast on anti-oxidation performance and immune performance and provided data for Se-yeast application in the transition dairy cows.Experiment 1. Effects of different level Se-yeast on anti-oxidation performance and Immune performance of prepartum dairy cowsA total of 20 Chinese Holstein dairy cows whose body condition, parity, the expected calving period were similar. The experiment was a randomized complete blocks design, dairy cows were randomly divided into four groups: control group (basic diet)(0.29mg Se/kg DM), 2.4g/d group(basic diet+2.4g Se-yeast/day)(0.49mg Se/kg DM), 4.8g/d group(basic diet+4.8g Se-yeast/day)(0.69mg Se/kg DM), 7.2g/d group(basic diet+7.2g Se-yeast/day)(0.89mg Se/kg DM). The results of the blood sample analysis showed that:Effect of Se-yeast in different supply levels on blood Se contents of prepartum dairy cows peripheral blood was different at different times before calving. The Se-yeast could increased blood selenium contents at the fourteenth day before calving and calving day. The Se-yeast could not increased blood Se contents in comparison with control group at the seventh day before calving.Serum GSH-px activity had different changes at different times before calving, GSH-px activity increased accordingly with supply level of Se-yeast increasing at the fourteenth day before calving and calving day. GSH-px activity decreased with supply level of Se-yeast increasing at the seventh day before calving. Serum SOD activity increased first and then decreased with supply level of Se-yeast increasing at the fourteenth day before calving and calving day. SOD activity with supply level of Se-yeast increasing increased at calving day. Serum T-AOC increased first and then decreased with supply level of Se-yeast increasing at different times before calving. The serum MDA concentration decreased first and then increased with supply level of Se-yeast increasing at the seventh day before calving and calving day. The serum MDA concentration decreased accordingly with supply level of Se-yeast increasing at the fourteenth day before calving.Peripheral blood lymphoid transformation was increased by supplying Se-yeast for prepartum dairy cows, Lymphoid transformation decreased with supply level of Se-yeast increasing. Serum IgM, IgG and IgA concentration increased first and then decreased with supply level of Se-yeast increasing at different times before calving.It was concluded that 2.4g Se-yeast/day(0.49mg Se/kgDM) had better improvement on blood Se contents and Anti-oxidation performance.Experiment 2. Effects of different level Se-yeast on anti-oxidation performance, Immune performance and lactation performance of postpartum dairy cowsA total of 20 healthy Chinese Holstein dairy cows whose calving date, parity, body condition were similar. The experiment was a randomized complete blocks design, Dairy cows were randomly divided into four groups: control group (basic diet)(0.42mg Se/kg DM ), 3.2g/d group(basic diet+3.2g Se-yeast/day)(0.62mg Se/kg DM), 6.4g group(basic diet+6.4g Se-yeast/day)(0.83mg Se/kg DM)and 9.6g/d group(basic diet+9.6g Se-yeast/day)(1.03mg Se/kg DM). The results of the blood sample analysis showed that:Whole blood Se concentration and milk Se concentration increased differently with supplying level of Se-yeast.Serum GSH-px activity was increased differently by supplying level of Se-yeast for postpartum dairy cows. Serum GSH-px activity increased accordingly with supply level of Se-yeast increasing at the fourteenth day and seventh after calving. Serum GSH-px activity decreased with supply level of Se-yeast increasing at the twenty-first day after calving. Serum SOD activity increased first and then decreased with supply level of Se-yeast increasing at postpartum. Serum T?AOC was increased differently by supplying level of Se-yeast for postpartum dairy cows, Serum T?AOC decreased with supply level of Se-yeast increasing. The serum MDA concentration decreased firstnd then increased with supply level of Se-yeast increasing at postpartum.Peripheral blood lymphoid transformation was increased by supplying Se-yeast for prepartum dairy cows, Lymphoid transformation decreased with supply level of Se-yeast increasing. Serum IgM, IgG and IgA concentration had different changes at different times at postpartum. Serum IgM, IgG and IgA activity increased first and then decreased with supply level of Se-yeast increasing at senventh and twenty-first day after calving.Milk production wasn't influnced by Se-yeast; Cream, milk protein, lactose, milk urea nitrogen and total solids were not influnced by Se-yeast.It was concluded that 6.4g Se-Yeast /day(0.83mg Se/kg DM)had better Anti-oxidation performance and immune function for postpartum dairy cows.