Effect of age at the onset of natural molting on carcass traits, muscle oxidative stability, and amino acid and fatty acid profiles in commercial laying hens

The aim was to evaluate the effect of age at the onset of natural molting on carcass traits, muscle oxidative stability, amino acid and fatty acid profiles in laying hens. According to the first signs of molting, 96 ISA Brown laying hens were selected to construct 3 equal groups, where birds molting at weeks 66–70, 71 to 75 and 76 to 80 were identified as “early molting” EM, “mid-molting” MM and “late molting” LM, respectively. There were no significant differences in the dressing percentage between the experimental groups. Meanwhile, the EM group showed greater abdominal fat percentage (4.82%). The EM group exhibited higher breast n3-PUFA contents (α-Linolenic, eicosatetraenoic, eicosapentaenoic and docosahexaenoic) (0.953, 1.04, 0.77 and 0.58 g 100 g−1, respectively). Moreover, the EM group showed greater breast isoleucine, valine and arginine contents as compared to the LM group (3.52, 4.08 and 5.35 g 100 g−1, respectively). The EM group exhibited lower concentrations of malondialdehyde in the breast (14.9 nmol/g) and thigh (17.4 nmol/g) muscles. In conclusion, the EM laying hens showed higher n3-PUFA and better oxidative stability of breast and thigh muscles. Hence, the EM laying hens may be used as an attractive source of chicken meat.