Effects of seminal plasma cholesterol and androgen levels on breeding rooster sperm motility in vitro.

Cholesterol and androgens play key roles in sperm maturation, capacitation, and fertilization ability. Thus, they influence sperm motility and stability, which are important indicators of male fertility. Their effects on the reproductive ability of roosters, however, remain unclear. In this study, we aimed to investigate the effects of seminal plasma cholesterol and steroid hormone levels on sperm motility in breeding roosters and clarify the associated mechanisms. Using semen from Yufen 1 rooster breeders, high motility group (HMG) and low motility group (LMG) models were established and thereafter their sperm characteristics were examined. The results obtained showed normal morphological structures, with intact heads and plasma membranes for sperms from HMG individuals, while those from LMG individuals had swollen heads and ruptured plasma membranes. Further, compared to HMG individuals, LMG individuals showed significantly higher seminal plasma cholesterol, testosterone, and follicle stimulating hormone levels. Possibly, at high concentrations, cholesterol crossed the blood-testis and blood-epididymal barriers and thereafter, disrupted cholesterol homeostasis in the sperm membrane, leading to the low sperm motility observed for LMG individuals. Additionally, plasma membrane and DNA integrity rates were significantly higher for HMG individuals than for LMG individuals, suggesting that plasma membrane and DNA integrity are critical for maintaining sperm motility. Taken together, these findings may be employed to improve fertilization rates in poultry production and may also serve as a foundation for further studies on breeding rooster utilization rates.