Abstract: In the experiments 50 broiles reared to 14 d are selected ,randomly is divided into 5 groups of 10 broilers.During 14 to 42 d the test group Ⅱ, Ⅲ, Ⅳ are administrated continuously ChIFN-α in drinking water followed by 0.1,1.0 and 10 U/mL respectively. Ⅰ group as the control group is only given water.Ⅴ group as positive control is administrated 50 mg/L levamisole hydrochloride. The experiments is designed to study the effects of ChIFN-α on immune function and growth performance after the broilers are administrated in drinking water. The results show ChIFN-α can increase the total number of leukocytes in peripheral blood of broilers,the percentage of lymphocytes, the percentage of basophils,reduce the percentage of neutrophils and monocytes, raise chickens spleen index,as well as the concentration of serum total protein (TP), serum albumin (ALB),serum globulin (GLO) and ALB/GLO ratio; and can not impact on the broiler growth and development obviously after drinking administration. As a result, administration of low-dose ChIFN-α in broilers drinking water can enhance the immune function of broilers, and can not impact significantly on the growth the healthy broilers.

Key words: broilers; ChIFN-α; drinking administration; low-dose; immune function; growth performance