Abstract
This study aimed to evaluate the effect of altitude on some male fertility related traits in Saudi sheep and goats. Testicular tissues were collected from a slaughterhouse in Taif governorate (1800 m above sea level) and Makkah governorate (sea level). Sperm characteristics (1 - individual motility, 2 - percent live sperm 3 - percent abnormal sperm) were examined. Semi-quantitative RT -PCR assay was used to evaluate the expression of IGF-II, StAR, LDLr and CYP11A genes. No significant effect of altitude on tested sperm parameters was revealed. Expression of IGF-II gene in both sheep and goats was significantly (P<0.05) higher at sea level compared to high altitude. A similar effect of altitude on StAR gene expression was only observed in goats, while in sheep the level of effect did not reach the significance threshold. Moreover, LDLr gene expression was significantly (P<0.05) higher for both sheep and goats at high altitude than at sea level. The CYP11A gene expression was significantly (P<0.05) higher in high altitude sheep than in those raised at sea level, while the opposite trend was observed for goats. In conclusion, high altitude had an effect on the expression of some studied male fertility related genes, but sperm parameters were not significantly affected.