Effects of dietary sodium butyrate on reproduction in adult breeder roosters.

Sodium butyrate (SB) is a novel feed additive in poultry production. This study aimed to evaluate the effects of dietary supplementation of SB on the reproductive performance of the rooster. Three hundred 22-week-old roosters were randomly divided into 2 dietary treatment groups of 6 pen replicates, a basal diet (control) group and a basal diet with SB gruop. The supplementation of SB was carried out through 23 consecutive weeks from 22 to 45 weeks of age. During this period, the live-weight was measured weekly while semen samples were collected every two weeks. Three time-points were chosen for analysis (30, 35 and 45 weeks of age). The results showed that SB improved the semen volume and sperm motility at 30 and 35 weeks of age (P < 0.05), increased the sperm concentration and decreased the abnormal sperm percentage during the whole experimental period (P < 0.05). These improvements were accompanied by increased testosterone levels at 30 and 35 weeks of age (P < 0.05). Moreover, dietary supplementation of SB also increased the enzyme activities of glutathione peroxidase (GPx) at 30 and 35 weeks of age and superoxide dismutase (SOD) at 45 weeks of age in the testes of roosters (P < 0.05). These results suggest that SB may promote testicular growth by increasing the antioxidant capacity and testosterone hormone secretion in adult roosters.