The effects of dietary amino acid density in broiler feed on carcass characteristics and meat quality

The advantages to broiler performance of feeding increased amino acid (AA) densities have been well documented, but minimal research has been reported on the effects of AA density on meat quality. In the current study, Ross x Ross 308 male broiler chicks were obtained from a commercial hatchery and fed diets with either deficient, low, high, or excessive dietary AA density during the finisher phase (28 to 42 d, in pellets). Broilers were slaughtered at 42 d of age and evaluated for live performance, carcass traits, breast and thigh composition, and breast and thigh meat quality. As expected, FCR decreased (P < 0.05) and yields improved (P < 0.05) as the AA density increased, but no differences (P > 0.05) existed among treatments with regard to final pH, cooking loss, shear force, proximate analysis, and average consumer acceptability of breast meat. The deficient AA diet yielded thigh meat with less (P < 0.05) moisture, less protein (P < 0.05), and more fat (P < 0.05) than thigh meat from all other treatments. In addition, the high and excessive AA treatments had higher (P < 0.05) concentrations of linoleic and linolenic acids in the thigh meat when compared with the deficient and low AA treatments, and thigh meat from the excessive AA treatment was more susceptible to oxidation (P < 0.05) than that from the deficient and low AA treatments. Overall, all 4 AA diets yielded high-quality breast and thigh meat, whereas the high AA diet yielded broilers with excellent live performance, carcass traits, and meat quality.