Effect Of Yeast Culture On Immunity,Antioxidation And Performance Of Dairy Cows With Subclinic Mastitis

Twenty-four mid-lactation dairy cows which had been infected recessive mastitis were divided into three treatments, i.e.Control(8 heads),Diamond V XP(8 heads) groups and Maikeli(8 heads) groups, which were grouped into three blocks based on the parity, milking days and milk production. The three treatments wereâ… ) control (the cows were fed with basal diets),â…¡) yeast culture 1(60 g/cow daily of Diamond V XP were added into the basal diets), andâ…¢) yeast culture 2(150g/cow daily of Maikeli were added into the basal diets). The test lasted 45 days. The result showed that:1. YC supplement increased the transformational rate of T-lymphocyte(P<0.05) significantly in the treatment ofâ…¡; it increased the rate of CD4+/CD8+ of T-lymphocytes significantly at the final YC supplement in the treatment ofâ…¡(P<0.01); YC supplement increased the concentrations of serum IgG(P<0.05)significantly and tended to increase the concentrations of serum IgA(P>0.05).2. YC supplement decreased the concentrations of malondialdehyde(MDA)in the treatment ofâ…¡andâ…¢, however, it increased the activities of plasmatic SOD (P<0.05)significantly in the treatment ofâ…¡and tended to increase the activities of plasmatic GSH-Px(P>0.05)in the treatment ofâ…¡andâ…¢.3. YC supplement made an increase in daily milk production(P<0.05)and it increased the Percentage of milk fat(P<0.05)significantly in the treatment ofâ…¡and decreased the percentage of milk suger(P<0.05)significantly in the treatment ofâ…¢, YC supplement decreased obviously the somatic cell count(SCC)in the treatmentâ…¡andâ…¢, YC supplement improved the quality of milk.