Breed-related number and size of muscle fibres and their response to carcass quality in chickens

Abstract

The present study was aimed to investigate the number and size of muscle fibre and their relation to carcass quality traits in chickens (slow- and fast-growing chicken strains). A total of 40 one-day-old Arbor Acres broiler (fast-growing) and 40 Thai native chickens (slow-growing) were reared to 45 and 112 days, respectively. The Arbor Acres broilers had heavier live weight, higher breast and thigh percentage than Thai native chickens (P<0.001). In breast muscle, there was no significant difference in total number of fibres and perimysium thickness. Thai native chickens had smaller fibre diameter and fibre area (P<0.01), and thicker endomysium in comparison with Arbor Acres broiler (P<0.001). The difference between the thigh and breast muscle fibre characteristics was not significant (P>0.05). The fibre diameter was positively correlated with live weight (P<0.05) and breast percentage (P<0.01). Endomysium thickness was correlated with live weight and breast percentage (P<0.05). There was no significant difference for the correlation between muscle fibre characteristics and thigh muscle. These results suggest that muscle fibre characteristics might be related to carcass quality.