Changes in Carnosine and its Related Constituents during Embryonic Development in the Breast Muscle of Layer and Broiler Chickens

Developmental changes in the levels of carnosine (b-alanyl-L-histidine), its derivative anserine (b-alanyl-1-methyl-L-histidine), and their constituents including b-alanine, L-histidine and 1-methylhistidine in the pectoralis muscle were investigated. Comparisons were made between broiler and layer type chickens at various embryonic stages (E14 and E18) and hatch (P0). Carnosine and anserine levels increased toward hatch and carnosine levels were higher in broilers than in layers. The b-alanine level was highest at E18 in both types of embryos. L-Histidine and 1 -methylhistidine levels were comparable during embryogenesis, but 1-methylhistidine greatly increased at P0. No significant differences in dipeptide constituents were found between broilers and layers. In conclusion, concentration of carnosine was higher in broilers than in layers.