Effect of Dietary DL-Methionine Supplementation on Growth Performance, Serum Biochemical Indices, and Carcass Characteristics of Broiler Chicken

Abstract

An experiment was conducted to evaluate the effect of dietary supplementation of DL-methionine (DLM) on growth performance, serum biochemical indices, and carcass characteristics of broiler chickens.  One hundred and twenty (120) day-old, commercial run broiler chicks were randomly distributed into 4 groups with 6 replicates of 5 chicks in each replicate.  A basal diet was prepared to meet the nutrient requirements of broilers during different phases of life (Pre-starter, 0-14 d; Starter, 15-28 d; Finisher, 29-42 d) except DLM (0.4%), which served as a control. Subsequently, three experimental diets were formulated to contain DLM at 0.45, 0.50, and 0.55%. Each diet was fed at random to 6 replicates of 5 chicks each throughout the experimental period of 6 weeks. The birds were maintained in a deep litter system of housing with standard managemental practices. The body weight gains increased, and the feed conversion ratio improved significantly (P<0.05) by increasing the level of DLM from 0.40 to 0.45% in the diet. No further advantage on BWG or FCR could be observed by further increasing the dietary levels of DLM to 0.50 or 0.55%. The BWG and FCR of broilers during 4-6 weeks and 0-6 weeks were not influenced due to the levels of dietary DLM in the present study. The serum concentrations of calcium, phosphorus, uric acid, triglycerides, and cholesterol were not influenced by the levels of dietary DLM. However, the concentration of protein in the serum increased by increasing the level of DLM increased from 0.40 to 0.45%. The levels of dietary DLM (0.40-0.55%) did not influence dressed yield, liver, heart, gizzard, giblet, and abdominal fat content of broiler chickens. From the findings of the present study, it is concluded that a 0.45% level of DLM in the diet is adequate for eliciting optimum performance in broiler chickens during 0 to 6 weeks of age.