Effect of dietary antioxidant supplementation on reproductive characteristics of male broiler breeders during the post-peak production phase

Abstract

Because of their membrane constitution, sperm cells of male broiler breeders are prone to lipid peroxidation, which affects their fertilizing capacity. The aim of the present study was to evaluate the effects of antioxidant diet supplementation on the reproductive characteristics of 12 male broiler breeders (Cobb) older than 50 weeks. The roosters were randomly distributed in a completely randomized experimental design with two treatments (treatment 1: commercial feed; treatment 2: commercial feed supplemented with canthaxanthin, lycopene, and vitamin C) and 6 replicates. Semen samples were collected by abdominal massage, and then underwent evaluation of semen volume, sperm concentration, motility, vigor, and morphology. Morphometric analyses of testes, combs, and dewlaps were performed at 68 weeks. Testes samples were collected for morphometric analysis of seminiferous tubules and analysis of cellular proliferation in the germinal epithelium by using immunohistochemical staining with anti-proliferating cell nuclear antigen (anti-PCNA) antibodies. Statistical data analysis was performed using the SAS software (SAS, 2002). No significant effects of antioxidant supplementation were observed on semen characteristics (p > 0.05). A significant positive effect of the antioxidant blend was observed on the percentage of normal sperm, dewlap weight and width, and testes weight and length (p < 0.05). PCNA-positive cell counts and morphometry of the seminiferous tubules were not affected by the treatment. Dietary antioxidant supplementation may represent a nutritional tool to increase fertility in male broiler breeder flocks during the post-peak production phase.