The aim of this study was evaluation of the effect of reduced protein diets on performance, immune responses and carcass traits of Japanese quails. One-day-old Japanese quail chicks (320) were randomly distributed into 16 cages (4dietary treatments×4 replicates) with 20 chicks in each experimental unit. Treatments were consisted of diets formulated with4 levels of crude protein (CP): A) 21% CP; B) 22%CP; C)23% CP; D)24% CP. Average feed intake, body weight gain and feed conversion ration of the quails within 6 wk of weekly were measured.At 35 d of age two bird of each replicate were inoculated intravenously with 0.2ml of a 1%suspension of SRBC (Sheep Red Blood Cell). Blood samples were collected at the end of period from wing vein. SRBC and white blood cells count were measured respectively by Micro titre Hemagglutination and Wright staining method. Two birds from each cage were slaughtered at 42 d. Body weight gain, feed intake and feed conversion ratio were significantly affected by different diets on 2wk and 6 wk (p<0.05).Different levels of protein did not significantly affect the carcass traits (P≥0.05).The highest antibody titers to the non-replicating antigen, SRBC, and Heterophil to lymphocyte ratio were affected by different levels of protein. The results suggest that the reduced protein diets up to 21% crude protein had not adverse effect on quail performance, carcass traits and blood parameters.
