Effect of dietary selenium on boar sperm quality.

The primary objective of this research was to evaluate the effect of long-term dietary selenium supplementation of commercial swine diets on semen production and sperm quality. The dietary treatments were a non-supplemented basal diet or the basal diet supplemented with 0.3ppm selenium in either an organic or inorganic form. A secondary objective was to determine if there were any beneficial effects of dietary selenium supplementation on changes in sperm quality during storage of semen post collection. Boars were fed dietary treatments from weaning at 20.97±0.18 d of age until the study was terminated when they were 382.97±0.18 d of age. Boars (n=6 per treatment) were maintained on a 1 time per week collection frequency for 5 months. Immediately after this, boars were collected six times over a 4 day period. Ejaculates were extended in a commercially available, 5-day semen extender and evaluated on day 1 and 6 of storage post-collection. Boars fed the organic selenium had higher (P<0.01) plasma levels of selenium compared to control boars and similar levels to those supplemented with the inorganic form (P=0.18). Dietary treatment did not affect (P>0.2) volume, concentration, total sperm in the ejaculate, sperm motility, progressive motility, morphology, lipid peroxidation, or glutathione peroxidase activity. These results indicate that supplementing a basal diet with organic or inorganic selenium did not affect semen quantity or sperm quality in fresh ejaculates nor did it appear to have any beneficial latent effects in extended semen stored post collection.