Evaluation of varied dietary crude protein and threonine amino acid levels on immune response and blood biochemical parameters in Iranian native turkeys

The present study aimed at investigating the effects of different dietary crude protein (CP) and threonine (Thr) levels on immune response and blood biochemical parameters on Iranian native turkeys. A total of 160 native turkeys with 4wk of age were randomly assigned to a 2×5 factorial arrangement. Treatments including three different CP dietary levels (90 and 100% of NRC recommendations) and Thr in 5 levels (0.75, 0.85, 0.95, 1.05 and 1.15% of diet). Results indicated that reduction of dietary CP level not significantly effect on cell-mediated and humoral immune response and blood serum parameters (P>0.05). Also different amounts of threonine not influenced on cell-mediated immune response and antibody response versus SRBC in 7 days after injection in native turkeys (P>0.05). However, in secondry challenge, treatments containing 0.85 and 1.15 % threonine had highest antibody concentration versus SRBC and had significant difference with groups of 0.95 % threonine (P0.05), However level of 1.05 of threonine significantly increased serum total protein and uric acid concentrations in serum native turkeys (P.05). Results of present study generally indicated that supplementation of Thr amino acid to diet could be improve humoral immune response and increase serum uric acid level in native turkeys, However different amounts of CP had not affect on this parameters.