Testicular Cell Indices and Peripheral Blood Testosterone Concentrations in Relation to Age and Semen Quality in Crossbred (Holstein Friesian×Tharparkar)
With the rise of crossbreeding to augment milk production, it is observed that there is problem of sub-fertility and infertility in crossbred males. Poor semen quality may be attributed to impaired spermatogenesis, endocrine disturbances and accessory gland infections. The present study was designed to explore the relationship among peripheral blood testosterone concentrations, different testicular cells and their indices and semen quality in crossbred bulls of different age groups. Three different age groups of crossbred males viz. bull calves (6 months), young bulls (15 months) and adult bulls (4 to 6 years) were utilized for the study. Testicular fine needle aspiration cytology technique was used to quantify testicular cytology and their indices. Peripheral blood testosterone concentrations were measured using ELISA method. Semen samples collected from adult bulls were microscopically evaluated for quality parameters. Mean peripheral blood testosterone concentrations in adult bulls (5.66 ng/mL) were significantly different from young bulls (1.42 ng/mL) and bull calves (2.28 ng/mL). There was no significant difference between the proportion of different testicular cells in bull calves and young bulls. Between young and adult bulls, significant differences were observed in the proportion of spermatocytes, spermatozoa, and sperm: Sertoli cell ratio. The proportions of Sertoli cells showed a significant difference between the three age groups. The number of primary spermatocytes had a high positive correlation with peripheral blood testosterone concentrations in bull calves. Number of Sertoli cells per 100 germ cells was negatively correlated with blood testosterone concentration in young bulls. Among different semen parameters in adult bulls, ejaculate volume had positive relationship, and sperm motility had significant negative correlation with testosterone concentrations. The number of Sertoli cells and Sertoli cell index had a positive correlation with various semen quality parameters. It may be concluded that number of Sertoli cells and Sertoli cell index are good indicators of semen quality.
For more details the original article may be referred in the following link - http://ajas.info/journal/view.php?doi=10.5713/ajas.2014.14139