Effect of dietary supplementation with Saccharomyces cerevisiae on reproductive parameters of rabbit bucks

The objective of the present study was to evaluate the effect of dietary supplementation with the prebiotic Saccharomyces cerevisiae yeast on testicular width and semen quality in rabbit bucks. Twenty-four male rabbits were randomly assigned to three groups and their semen was sampled for 8 weeks: a control group (C) fed with a conventional diet without S. cerevisiae, a group supplemented with 0.3 g of S. cerevisiae/kg of feed (T1) and a group supplemented with 1 g of S. cerevisiae/kg of feed (T2). Testicular width was determined using a caliper. Semen was collected from each buck and evaluated for sperm volume, motility, percentage of live sperm and morphological characteristics. The results showed that both right and left testicles were greater (P < 0.01) in width in group T1. Regarding semen parameters, progressive sperm motility was higher (P < 0.01) in the T2 group compared to the C and T1 groups. A significant decrease (P < 0.01) in the percentage of spermatozoa with abnormal mid-piece and flagellum was observed in the T2 group compared to the other groups. Furthermore, the percentage of undeveloped sperm decreased (P < 0.01) in both T1 and T2 groups. However, semen volume and percentage of live sperm did not vary between groups (P > 0.05). These results suggest that S. cerevisiae improved the progressive sperm motility and morphological characteristics at the rate of 1 g kg-1 of feed.