Abstract: The study was to investigate the effect of dietary supplementation with different proportion of Bacillus licheniformis and Bacillus subtilis on nitrogen use and plasma biochemical parameters of Partridge shank chickens.Six hundred of Partridge shank chickens were randomly allocated into six groups with four replicates of 25 each.The control group was fed a basal diet, groups Ⅰ to Ⅴ were fed the basal diet supplemented with different proportion of Bacillus licheniformis and Bacillus subtilis, the proportion of each group were 0.5%:0.5%, 0.33%:0.66%, 0.25%:0.75%, 0.66%:0.33%, 0.75%:0.25%.The trial lasted for 56 days.The results showed that compared with the other groups, the plasma ammonia content and xanthine oxidase activity in group Ⅳ were significantly decreased (P< 0.05).Compared with the control group, the plasma uric acid contents in groups Ⅰ, Ⅱ, Ⅳ and Ⅴ were significantly decreased (P< 0.05), the plasma urea and intestinal urea nitrogen content in groups Ⅰ, Ⅱ, Ⅲ and Ⅴ was significantly decreased (P< 0.05), the plasma albumin content and A/G in group Ⅳ were significantly decreased (P< 0.05), while the globulin content was significantly increased (P< 0.05).There were no significant differences in plasma total protein content and aspartate aminotransferase and alanine amiotransferase activity among all groups (P >0.05).In conclusion, dietary supplementation Bacillus licheniformis and Bacillus subtilis with the dose of 0.66%:0.33% could significantly improve the efficient of nitrogen use and plasma biochemical parameters.

Key words: compound Bacillus; Partridge shank chickens; nitrogen use; plasma biochemical parameters