Perspectives on vitamin E, canthaxanthin and selenium to chick embryo antioxidant protection

The egg provides the nutritional support for the development of the embryo; thus, the embryo's antioxidant system can be enhanced with antioxidant supplementation agents in the breeder's diet or antioxidant supplementation agents in in ovo feeding. The 19th day of broiler embryonic development can be cited as a moment of increased oxidative action on chick embryo tissues as on the 18th day of development, the chick starts the internal pipping of the air chamber and starts to have a greater oxygen supply, which can intensify the oxidative action and the generation of free radicals. The use of vitamin E in doses higher than 200 mg/kg in the breeders' feed influences the oxidative protection in the egg yolk, with a greater concentration of antioxidant enzymes (GSH-Px activity, SOD and catalase) in the serum, liver and musculature of breeders and in the serum of newly hatched chicks. Canthaxanthin (6 mg/kg) in the broiler breeders' diet is efficient in improving the results of egg fertility, hatchability and oxidative status of the newly hatched chick. Supplementing selenium in the breeder's feed is capable of increasing the availability of selenium for embryonic development and increasing the antioxidant capacity of the embryo's tissues, increasing the hatching. Vitamin E in ovo feeding was studied, but the doses administered need to be further investigated because there is a certain discrepancy between the results found. The only study that evaluated a commercial product containing canthaxanthin in ovo indicated an improvement in the antioxidant capacity of the embryo; however, it was recommended that the studies are carried out to elucidate the use of pure canthaxanthin. The present review found that oxidative protection of embryonic tissues during development and at hatching period is essential for an incubation with a high number of hatched chicks and a low incidence of embryonic mortality.