Effects of dietary supplementation with <i>Candida krusei</i> on production performance, immune function and ammonia nitrogen emission in broilers

This study aimed to investigate the effects of dietary graded levels of Candida krusei on growth performance, slaughter performance, immune function, nitrogen metabolism and ammonia nitrogen emission of broilers. A total of 240 1-day-old AA broiler chickens were randomly divided into 4 groups with 6 replicates of 10 broilers each. The control group (CK) was fed a basal diet, and treatment groups were supplemented with 1.0 × 108 CFU/kg (LSAL), 1.0 × 109 CFU/kg (LSAM) and 1.0 × 1010 CFU/kg (LSAH) of Candida krusei in basal diet, respectively. The results indicated that LSA significantly improved the average daily gain and average daily feed intake of broilers during d 1–21 (p < 0.001). Compared to the CK group, the LSAH group significantly exhibted a higher eviscerated carcase weight rate, and lower abdominal fat rate (p < 0.05). Blood concentrations of urea nitrogen, uric acid and ammonia significantly decreased with increasing Candida krusei levels(p < 0.05). Furthermore, Candida krusei significantly reduced ammonia nitrogen content in the excreta (p < 0.001). In conclusion, dietary supplementation with Candida krusei can improve the growth performance, slaughter performance and nitrogen metabolism of broilers, and also mitigate the ammonia nitrogen emission, which suggests that Candida krusei is a potential probiotic additive in chickens. When supplemented to diet of broilers, 1.0 × 1010 CFU/kg Candida krusei was recommended.