Dietary Canthaxanthin Supplementation Promotes the Laying Rate and Follicular Development of Huaixiang Hens

SIMPLE SUMMARY: Huaixiang chicken is a famous local broiler in China. It has excellent meat quality, but its disadvantage is a low laying rate. At present, improving the laying rate of poultry via nutritional regulation has attracted the extensive attention of researchers. Canthaxanthin(CX) is a ketocarotenoid, which widely exists in marine animals, algae, and a few terrestrial plants. It has been used in poultry production. In this study, dietary CX supplementation is found to increase laying rates, promote ovulation and maintain reproductive hormone levels by increasing serum and ovarian antioxidant levels. It is suggested that CX can be used to improve the laying rate of Huaixiang broiler breeders. ABSTRACT: Canthaxanthin(CX) is a ketocarotenoid, which is widely used in poultry production as a lipophilic antioxidant. Huaixiang chickens are a local breed in China famous for their excellent meat quality; improving their laying rate via nutritional regulation has attracted extensive attention. The aim of this study was to evaluate the effects of dietary CX on the laying rate and follicular development in Huaixiang hens. A total of 180 Huaixiang hens were randomly divided into five groups with six replicates, and six chickens per replication. The control group (CON) were fed a basal diet, and the treatment group (NT) were fed a basal diet supplemented with 4, 6, 8 and 10 mg/kg CX. All chickens were 26 weeks old, living at an average environmental temperature of 25 ± 2 °C with a relative humidity of 65–75%. The results showed that supplementing the CX improved the laying rate and large white follicles (LWF) number (p < 0.05) and increased the concentration of reproductive hormones (LH, FSH, E(2) and Prog) (p < 0.05), and the basal diet supplemented with 6 mg/kg CX worked best. Moreover, CX could increase the activities of antioxidant enzymes SOD and GSH-Px (p < 0.05) and reduce the content of the lipid peroxidation product MDA in Huaixiang chickens (p < 0.05); again, 6 mg/kg CX was best. In conclusion, dietary CX had positive effects on the laying rate, ovarian structure, reproductive hormone secretion, follicle development, and the antioxidant capacity of Huaixiang hens, and 6 mg/kg CX was recommended to be added to the diet of Huaixiang chickens.