Testicular Cell Indices and Peripheral Blood Testosterone Concentrations in Relation to Age and Semen Quality in Crossbred (Holstein Friesian×Tharparkar) Bulls

Abstract

Present study analyzed the changes in peripheral blood testosterone concentrations and testicular cytogram in relation to age and semen quality in crossbred males. Three different age groups of crossbred males viz. bull calves (6 months, n = 5), young bulls (15 months, n = 5) and adult bulls (4 to 6 years, n = 8) 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 enzyme-linked immunosorbent assay method. Semen samples collected from adult bulls were microscopically evaluated for quality parameters. Mean peripheral blood testosterone concentrations in bull calves, young bulls and adult bulls were 2.28±0.09 ng/mL, 1.42±0.22 ng/mL and 5.66±1.08 ng/mL respectively, and that in adult bulls were significantly different (p<0.01) from young bulls and bull calves. 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 (p<0.01) were observed in the proportion of spermatocytes, spermatozoa, and sperm: Sertoli cell ratio. The proportions of Sertoli cells showed a significant difference (p<0.01) between the three age groups. The number of primary spermatocytes had a positive correlation with peripheral blood testosterone concentrations in bull calves (r = 0.719, p<0.01). Number of Sertoli cells per 100 germ cells was negatively correlated with blood testosterone concentration in young bulls (r = −0.713, p<0.01). Among different semen parameters in adult bulls, ejaculate volume (r = 0.790, p<0.05) had positive relationship, and sperm motility had significant negative correlation (r = −0.711, p<0.05) with testosterone concentrations. The number of Sertoli cells and Sertoli cell index had a positive correlation with various semen quality parameters (p<0.001). Results of the present study conclude that number of Sertoli cells and Sertoli cell index are good indicators of semen quality, but peripheral blood testosterone concentrations may not have a direct relationship with various seminal attributes in crossbred bulls.

Beyond Testis Size: Links between Spermatogenesis and Sperm Traits in a Seasonal Breeding Mammal

“…On the other hand, sperm traits can evolve independently but in the same direction (reviewed by [ 61 ]), because they share the same goal and are the final product of an efficient spermatogenesis. In spite of some discrepancies in what sperm number and quality parameters are considered, our findings are consistent with inter- [ 14 , 62 , 63 ] and intra-specific [ 9 , 22 , 64 ] studies supporting that sperm quantity and quality are correlated with one another most likely to maximise sperm fertilisation efficiency in red deer.…”

“…Our findings also reveal that the Sertoli cell number is positively associated with sperm parameters in red deer, supporting what was recently found by Rajak et al . [ 9 ] in bull. Therefore, changes in the Sertoli cell number not only affect the magnitude of sperm production [ 43 ], but also sperm function.…”

“…Recently, Rajak et al . [ 9 ] found that, in adult bulls, the Sertoli cell index was positively associated with ejaculate sperm concentration, mass activity, individual motility, viability, and membrane integrity. Nevertheless, the relationship between the Sertoli cell traits and sperm quality has so far received no empirical testing in seasonal breeders, although these are valuable models for the study of seasonal regulation of testis function [ 10 ].…”

“…Even though the links between the testicular morphology and sperm traits have been explored in comparative studies [ 11 – 14 ], little is known at the intra-specific level [ 9 , 15 ], in spite of the major functional significance. Studies using intra-specific variation in testes investment are powerful and instructive also from an evolutionary perspective because they may reveal the underlying processes governing any observed inter-specific pattern [ 16 ].…”

Effect of live weight on libido, sperm quality, testosterone and lute-inizing hormone in replacement stock of Ongole Grade bull

“…While the relative importance of either hormone appears somewhat different between rodents and primates, generally, however, both LH/testosterone and FSH are necessary for quantitatively normal spermatogenesis, at least in non-seasonal species. Borg et al (1991) found no significant alterationsin testosterone levels associated with sexual behavior, although values were different for Angus bulls with different reproductive behavior performanceand different age (Sekoni et al, 2010;Rajak et al, 2014). As a result of increase concentrations of LH hormone leads to decrease testosterone hormone concentration in group IV that could ultimately lead to low libido behavior of group II and III (Table 2).…”