Effect of L-Threonine Supplementation in Diets on Immune Response and Carcass Traits in Broiler Chickens

Abstract

Three hundred straight-run ‘Cobb 400’ day-old broiler chicks were randomly distributed into five treatment groups having three replicates containing 20 chicks in each and reared up to 6 weeks of age. The dietary treatment groups were the threonine deficient diet-Negative Control (A), Control diet containing  threonine level as per NRC (B), diet containing L- threonine 10% (C), 20% (D), 30% (E) above NRC, (1994) recommendation. At the end of 3^rd week, antibody titres against New Castle Disease (ND) were significantly (P<0.05) higher in treatment group C as compared to other treatment groups, whereas, there was non-significant difference in 6^th week of age. At the end of 3^rd and 6^th week of age the Infectious Bursal Disease (IBD) antibody titers were numerically higher in L-threonine supplemented groups but, differences were non-significant among all treatment groups. The edible carcass yield was slightly higher in l-threonine supplemented groups. The abdominal fat percentage in L-threonine supplemented group C at 10% above NRC level was numerically lower than control and other treatment groups. The results of the present trial suggested that the dietary supplementation of L-threonine at 10% above NRC were found to be beneficial in term of improved immune response and carcass traits in broiler chickens.