The avian embryo and its antioxidant defence system

During chick embryo development, there exists an antioxidant-oxidant balance in the tissues, which supports normal embryonic development and post-hatch chick viability. This balance is maintained by natural antioxidants including vitamins A, E, C and carotenoids, glutathione peroxidase (GSH-PX), catalase (CAT) and superoxide dismutase (SOD). Chick viability is an important factor in determining post-hatch health and profitability. Factors that interrupt growth and development during the embryonic period affect the overall performance and health during the post-hatch period. During the 21-day incubation period for chickens, antioxidant defence systems protect the embryo against the lipid peroxidation (LPO) derived from undesirable conditions. The purpose of this review is to explain the antioxidant mechanisms that contribute to chick embryo development resulting in a healthy hatchling.