Association of heat shock protein 70 levels with semen quality in crossbred Holstein Friesian bulls

Abstract

This study attempted to clarify the appearance of 70 kDa heat shock protein (HSP70) in spermatozoa and its relationship with the semen quality in crossbred Holstein Friesian (HF) bulls. Semen from 10 HF bulls was collected 8 weeks during rainy (THI = 79.06), winter (THI = 74.30), and summer (THI = 80.05). Semen quality was evaluated in terms of semen volume, sperm concentration, sperm motility, sperm viability, and percentage of abnormal spermatozoa. It was found that mass movement of sperm in the summer and rainy seasons were significantly lower than in the winter (P<0.01). The percentage of abnormal sperm were significantly lowest in the summer (P<0.01). The western blot analysis of the levels of HSP70 in spermatozoa found that it was significantly lower in summer than during winter and rainy seasons (P<0.01). The results of correlation revealed that the levels of HSP70 in spermatozoa had positive correlation with mass movement, percentage of total abnormal sperm, and percentage of secondary abnormal sperm (P<0.01). In conclusion, this study revealed the presence of HSP70 in the bullsí spermatozoa and it was associated with some traits of semen quality.