Effects of Dietary Variations in Methionine and Lysine Levels on The growth Performance and Carcass Characteristics of BLRI-improved Hilly Chicken

This study aimed to assess how different lysine and methionine supplementation levels affect growth and carcass characteristics in BLRI-improved hilly chickens. A total of 432-day-old chicks were randomly assigned to nine treatment groups, each with four replicates of 12 chicks. The birds were provided with an iso-energetic, iso-nitrogenous basal diet formulated from corn and soybean meal to meet their nutritional needs. A 3x3 factorial design was used, with three levels of lysine (NRC standard, 10% below, and 10% above) and three levels of methionine (NRC standard, 10% below, and 10% above), applied across starter (0–2 weeks), grower (3–5 weeks), and finisher (6–8 weeks) phases. Feed was provided ad libitum, and weekly measurements of body weight, weight gain, and feed intake were used to calculate feed conversion ratio (FCR). At eight weeks, eight birds per treatment were sacrificed for carcass analysis. Data were processed using SAS (2009), and differences were determined via DMRT. Results indicated that the NRC (1994) dietary standards for lysine (1.05%) and methionine (0.48%) achieved optimal growth during the grower and finisher phases, with significant increases in body weight and weight gain (p<0.05), while no significant effects were observed in the starter phase (p>0.05). Additionally, lysine and methionine supplementation had no significant impact on carcass traits. These findings suggest that for BLRI-improved hilly chickens, the NRC (1994) standards for lysine and methionine are sufficient for optimal growth, with no added benefits from deviations in either nutrient level.