Effect of hydrolyzed and live yeast supplementation during transition period on colostrum and milk composition and blood biochemical parameters in dairy cows

The main purpose of this study was to assess live yeast and hydrolyzed yeast effects on blood biochemical parameters, colostrum quality and performance of dairy cows during transition period. Fifteen pregnant Holstein dairy cows were randomly divided into three groups during three weeks pre- and post-parturition. Cows were assigned to treatments as: ۱) control group fed basal diet, ۲) cows fed basal diet plus ۶.۰ g/d/head live yeast and ۳) cows fed basal diet plus ۲۰ g/d/head hydrolyzed yeast as on top. Live yeast supplementation resulted in higher dry matter intake and milk production compared with hydrolyzed yeast and the control group. Cows received live yeast had the highest milk fat percentage and those in the control group had the lowest lactate dehydrogenase and alkaline phosphatase activities and those received hydrolyzed yeast had the highest IgG and lactoferrin in the colostrum. Cows received live yeast had the highest serum albumin and those in the control group had the lowest serum albumin. Cows received hydrolyzed yeast had the highest globulin among treatments. There was no difference among treatments for blood triglyceride, cholesterol, non-esterified fatty acids and beta-hydroxy butyric acid. Cows in the control group had the highest aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase activities in the serum. Live yeast and hydrolyzed yeast supplementation reduced aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase in the serum. Cows receive hydrolyzed yeast had higher IgG level in the serum. Dietary supplementation of live yeast could improve feed intake and milk yield post parturition, but hydrolyzed yeast enhance immunity components of colostrum. Pre-parturition, supplementation of ۲۰ g/d/head hydrolyzed yeast in the diet of dairy cows recommended for enhancing immunity status of cow and her newborn and post-parturition, supplementation of ۶.۰ g/d/head live yeast recommended for better production performance.

کلیدواژه ها:

hepatic enzyme ، IgG ، immunity ، lactoferrin ، milk yield