Abstract:

This study was intended to investigate the effect of dietary methionine (Met) levels on slaughter performance,
meat quality and antioxidant capacity of breast muscle from broilers. A total of 144 one-day-old Arbor Acres broiler chicks
were randomly allocated to three treatment groups with 6 replicates of 8 birds each. The control broilers were fed a basal
diet containing 0.50% (from day 1 to 21) and 0.45% (from day 22 to 42) Met. The corresponding values for high and low
Met treatments were 130% and 70% of the control, respectively. The results showed that compared with the control group,
the high Met diet increased the percentage of breast muscle (P < 0.05), the low Met diet decreased eviscerated carcass yield
(P < 0.05). The high Met diet decreased the shear force, increased the pH24 h and the a* value of chicken breast muscle
(P < 0.05), whereas the low Met diet significantly increased the L* value (P < 0.05). The high Met diet significantly
improved total antioxidant capacity (T-AOC) (P < 0.05), while the low Met diet significantly decreased GSH content
(P < 0.05). In conclusion, dietary methionine levels may affect slaughter performance and meat quality by regulating protein
deposition and antioxidant capacity in breast muscle.

Key words: methionine, broiler, slaughter performance, meat quality, antioxidant capacity