Influence of live yeast culture (Saccharomyces cerevisiae) on milk production and composition, and blood biochemistry of grazing dairy ewes during the milking period

Abstract

A feeding trial was conducted to evaluate the influence of live yeast culture (Saccharomyces cerevisiae) on milk production, composition, and blood biochemistry of dairy ewes during the machine milking period. The control group (CD) was fed a concentrate mixture and hay and grazed twice daily, while the second (YS3) and third (YS6) groups were fed the same diet supplemented with 3 or 6 g of live yeast culture (Yea Sacc1026), respectively. The treated groups had significantly higher values (p < 0.05) for fat corrected milk (FCM) (1221, 1116 and 940 g/day, for YS6, YS3 and CD group, respectively) and fat-protein corrected milk (FPCM) (1204, 1103 and 931 g/day, for YS6, YS3 and CD group, respectively), while the values for milk yield, fat yield and lactose yield were higher (p < 0.05) only in the YS6 group compared to the CD group. Milk yield values were constantly higher in the YS6 group than in the control group while the values for the YS3 group were more variable during milking. Milk composition was not significantly affected by yeast supplementation with the exception of urea values which were lower (p < 0.05) in the YC6 group. Yeast administration influenced β-hydroxy-butyrate (BHB) values, which were higher (p < 0.05) in the treated groups; and non-esterified fatty acids (NEFA) values, which were higher (p < 0.05) only in the YS6 group compared to the control group. Other blood biochemistry values were not influenced by the treatments. We conclude that supplementation with live yeast culture, under the conditions of our experiment, had a significant effect on the performance and metabolism of grazing dairy ewes during the machine milking period. Based on more constant results, we could recommend the inclusion of live yeast culture (Yea Sacc1026) at 6g/animal/day as appropriate for field conditions.