The effects of <i>Saccharomyces cerevisiae</i> on performance and nutrients digestibility in broilers fed with diet containing different levels of phosphorous

Abstract

The effects of yeast culture (YC) with different levels of NPP (non phytate phosphorus) on performance, tibia and blood parameters and ileal digestibility of nutrients were investigated in broilers. A total of 720 one-day-old male broiler (Ross) chicks were divided into 48 groups and fed with 12 diets (4 groups per diet) for 42 days. The experimental design was a randomized complete block with a 3 × 4 factorial arrangement of treatments. The 12 treatments consisted of: 3 levels of NPP (normal, 80 and 60% normal level) and 4 levels of YC (0.0, 0.15, 0.3 and 0.45 % of diet). The results of this study showed that there were significant interactions (p<0.05) between NPP level and the concentration of YC in the diet with body weight gain (BWG) and feed conversion ratio (FCR) during the 42 days of the experiment. In the lower levels of NPP, the improvement of FCR was dose dependent on YC. No NPP dietary x YC combination interactions were found in the other measured traits. The lower levels of NPP significantly (p<0.05) decreased ileal digestibility of crude protein (CP) and calcium (Ca). The addition of YC significantly (p<0.05) increased ileal digestibility of both P and Ca. The enhancement of NPP dietary significantly (p<0.05) increased the concentration of P, Ca and ash in the tibia. Only birds fed with the diets containing 0.45% YC significantly had (p<0.05) higher ash percentage than the other groups. Serum Ca and P were significantly (p<0.05) affected by different levels of NPP in the diet. The effect of YC on concentration of serum P and total protein was significant (p<0.05). In conclusion, the increased retention of P, CP and mineral utilization in deficient-NPP diets by YC resulted in increased availability of P and Ca to the broilers, which could have led to improved growth performance.

Key words: Yeast culture, phosphorus, broilers, performance, digestibility.