Effect of organic selenium dietary supplementation on quality and fertility of cryopreserved chicken sperm.

Oxidative stress due to cryopreservation has been considered as a major factor in sperm damage. Supplementation of the diet with different concentrations of organic selenium has been proposed to improve the quality of fresh and frozen-thawed semen in different breeds of roosters. Sixteen Pradu Hang Dum (Thai native) and 16 Rhode Island Red roosters were used in this study. Four levels of selenium supplementation between 0 and 0.9 ppm were examined. After 14 days of feeding, semen samples were collected twice a week and the fresh semen was evaluated. Then semen from each group was pooled and cryopreserved. The fertility of frozen-thawed semen was determined by inseminating 48 layer hens. Supplementation of diets with 0.3, 0.6 and 0.9 ppm selenium improved the fresh semen in terms of sperm viability and normal morphology (P < 0.01). Sperm concentration increased (quadratically, P < 0.001) with increasing dietary selenium levels. Meanwhile, post-thawed semen quality in terms of sperm motility, viability, live with intact acrosome and functioning mitochondria improved significantly with selenium treatments of 0.6 and 0.9 ppm, and lipid peroxidation was decreased (P < 0.001) and fertility improved (P < 0.05) with those levels of selenium treatment. In addition, there were differences between breeds with respect to some fresh or frozen semen quality parameters (P < 0.05). In conclusion, the breed affected both fresh and frozen semen. Even there were no statistically significant differences in the parameters from groups 0.6 and 0.9 ppm on frozen-thawed semen quality, but the highest sperm concentration was found in 0.6 ppm. Therefore selenium supplementation of diets at 0.6 ppm was recommended to improve the quantity and quality of fresh and frozen semen.