Dietary carob fruit (Ceratonia siliqua L.) supplementation improves spermatogenesis, semen quality and embryonic death via antioxidant effect in aging broiler breeder roosters.

Rooster semen contains high content of long-chain polyunsaturated fatty acids; therefore, spermatozoa are very susceptible to lipid peroxidation. Carob fruit (CF) contains abundant amounts of flavonoid known as natural antioxidants and semen enhancers. The purpose of the study was to investigate the effect of dietary supplementation of CF on semen characters, blood parameters, immune response, testicular histology, and reproductive performance of aging broiler breeder roosters. Thirty-two 47-week-old Ross-308 breeder roosters were randomly assigned to either control or supplemented (CF, 0 or 1 g/kg diet) dietary treatment for 14 continuous weeks. Semen, blood and testis samples were collected at the end of trial. Furthermore, the rate of fertility and hatchability were evaluated using 440 natural mated hens. The sperm kinematic values and progression ratios, seminal antioxidant enzymes (superoxide dismutase and glutathione peroxidase) activity, and total antioxidant capacity of semen and blood were increased, and malondialdehyde concentration in semen and blood were decreased by dietary CF supplementation (P < 0.01). The treatment had no effect on the seminal sperm concentration, blood parameters and immune response to Newcastle disease virus vaccine. The testes weight, seminal tubes spermatozoids number, spermiogenesis index and repopulation index, were improved by dietary supplementation (P < 0.05). Fertility and hatchability rate of roosters in the CF group were insignificant. In conclusion, CF supplementation in aging roosters' diet enhanced the sperm motility, seminal and blood antioxidant capacity, and testicular spermatogenenic indexes.