Quality attributes in breast muscle from broilers of an Arkansas randombred line varying in growth rate

The physico-chemical quality attributes of meat from broilers with significant differences in growth rate were investigated in this study. Two chicken populations from a random mating broiler control population were established as a slow-growing subpopulation (SG) with an average growth rate of 229 g/wk and a fast-growing subpopulation (FG) with an average growth rate of 319 g/wk. The initial pH at 15 min and final pH after 24 h were higher (P < 0.05) in breast muscle from FG than muscle from the SG population. Muscle from the SG had higher (P < 0.05) L* and b* of 57.0 and 11.2, compared with L* and b* of 55.8 and 10.5 from the FG. Although no difference in a* was observed, hue angle was different (P < 0.05) at 52.7 and 50.4 in FG and SG populations, respectively. Water-holding capacity was 25 to 27% and not different between the populations, but 5-d drip loss at 8.48% was higher (P < 0.05) in the muscle from the SG compared with the FG at 6.44%. Cook yield was higher (P < 0.05) in the FG muscle at 86.92% compared with the SG muscle at 85.96%. There was a positive correlation of +0.20 between pH difference and drip loss only in the FG. Significantly higher (P < 0.05) cook yields were observed in muscle from FG than SG chickens. The lower weight, higher L* value, and lower initial and final pH values in the SG population, coupled with higher drip loss and lower cook yield, likely result from differences in growth rate.