Effect of Different Levels of Live Yeast in a High Concentrate Diet on Performance, Blood Constituents and Immune System Status of Zandi Lambs

A feeding trial with twenty-seven male weaned Zandi lambs (initial body weight 27.1±0.38 kg) was conducted to evaluate the effect of different levels of Saccharomyces cerevisiae SC47 in diet containing high concentrate (85%) on the growth performance, blood parameters and immune system status. Lambs were allocated to one of three treatment diets in a completely randomized design with 3 replicates and 3 observations per replicate including: 1) basal diet without yeast, control diet; (CD) 2) basal diet with 3 g yeast per lambper day, low yeast; (LY) and 3) basal diet supplemented with 4.5 g yeast per lambper day, high yeast; (HY). Regarding dry matter intake (DMI), there was no significant difference among treatments (P 0.05). Average daily gain (ADG) was greater in HY group, but differences among treatments were not significant (P 0.05). Feed conversion ratio (FCR) was not significantly affected by dietary treatments (P 0.05). Differences between concentrations of total protein, globulin and albumin/globulin ratio (A/G) were significant (P 0.05). The highest amount of total protein and globulin was observed in LY group (P 0.05). Lambs in CD group had the highest amount of A/G ratio. No significant differences were found for the hematology results (P 0.05). No significant differences were detected in differential white blood cells, except neutrophil band that was greater in HY group at the twelfth week (P 0.05).It is concluded that the use of dietary live yeast in high concentration can improve performance (P 0.05), plasma biochemical metabolites(P 0.05) and hematological parameters (P 0.05) in Zandi lambs.