Abstract
This study was conducted to evaluate the effects of common canthaxanthin (CC) or microencapsulated canthaxanthin (MC) combined with apo-ester (AE) on productive performance, egg yolk color and antioxidant capacity in laying hens. A total of 270 Hyline Brown laying hens at 56 wk of age were allocated to 3 groups with 6 replicates, and fed a wheat-soybean meal basal diet or the same diet supplemented with CC+AE or MC+AE at 5 mg/kg feed for each supplement. The productive performance was not affected by dietary treatments. The 2 test groups had higher (P < 0.05) yolk color score in fresh eggs than the control group, but the yolk color score of CC+AE group significantly declined (P < 0.05) with time, and a slight decline was also observed in the MC+AE group at 36 d. The MC+AE group had higher (P < 0.05) yolk color score of fried and boiled eggs than the other 2 groups. Higher (P < 0.05) feed canthaxanthin concentration was found in the MC+AE group at the end of experiment, which also had higher yolk canthaxanthin concentration in fresh eggs at 24 and 36 d as well as in fried, boiled and stored (4°C and 25°C) eggs. The 2 test groups had higher (P < 0.05) total antioxidant capacity in serum than the control group, and lower (P < 0.05) MDA content was observed in the MC+AE group. The mRNA level of cluster determinant 36 in jejunum was increased by the 2 test groups, and the same increase was also found in liver only in the MC+AE group. In conclusion, MC was more efficient in promoting yolk color and antioxidant capacity than CC when combined with AE.