Abstract: The present study was conducted to investigate the effect of various levels of methionine and metabolisable energy on carcass characteristics and visceral organs of broiler chickens. A total of 400 broiler chickens (Lohman) were allocated to a factorial 2x2 in completely random design with 4 replicates (25 birds in each). Levels of methionine were 1.2 and 0.45% which adjusted to 2800 and 3200 kcal kg-1 Metabolisable Energy (ME) in starters and 0.9 and 0.33% to 2800 and 3200 kcal kg-1 ME in grower periods, respectively. On 21st and 42nd days of age two birds were selected and after slaughter carcass and visceral organs characteristics were measured. The mentioned parameters were differently affected by all treatments. Moreover, the highest carcass weights percentage was obtained at 42nd days of age in low levels of methionine (p<0.05). Significant increases of breast were observed in chickens fed by low levels of methionine at 21st days of age (p<0.05). There were no significant differences between neck and backside weights at 21st days of age (p<0.05). All treatments caused significant differences in wing weights at 21st days of age (p<0.05). Significant increases in proventriculus were observed in 21st days of age (p>0.05). Also, significant changes were found in liver and heart weights at 21st and 42nd days of age in at this case (p>0.05). The results of current study have shown that various metabolizable energy and methionine interaction reflected in external (Carcass trait) and internal (Visceral organs) trait.
A.A. Saki, F. Mirzaaghatabar, P. Zamani and H. Aliarabi, 2011. Energy Utilization by Chickens Fed Graded Levels of Balanced Mixture of Methionine. Journal of Animal and Veterinary Advances, 10: 3212-3217.