Organic selenium enhances the antioxidative status and quality of cockerel semen under high ambient temperature.

1. The objective was to examine the effect of supplemental dietary organic selenium (Se) on improving semen quality and antioxidative status in male domestic fowls exposed to high ambient temperature. 2. Thirty-six Egyptian local cross males, 42 weeks old, were housed individually in cages in an open-sided building under 16 h L:8 h D and were provided with commercial feed and water ad libitum. In the house average daily temperature ranged from 33 to 36 degrees C and relative humidity from 60 to 70%. Birds were divided into 4 experimental treatments (n = 9) and were fed the basal diet supplemented with 0 (control), 01, 02 or 03 mg organic Se/kg in the form of a yeast source (Sel-Plex) for 8 weeks. 3. Under heat stress conditions, inclusion of organic Se in the cockerel diets enhanced the semen quality traits, including the sperm count and motility and reduced the percentage of dead sperms in a dose-dependent manner. 4. In seminal plasma, organic Se supplementation ameliorated some of the adverse effects of heat stress on lipid peroxidation and antioxidative properties. The inclusion of organic Se (03 mg/kg) in the cockerel diets doubled seminal plasma glutathione peroxidase (GSH-Px) activity, compared to controls and reduced lipid peroxidation. 5. In conclusion, supplemental dietary organic Se improved semen quality characteristics when cockerels were subjected to heat stress. It increased both sperm count and motility, reduced the percentage of dead sperm and enhanced the antioxidative status of seminal plasma.