Seasonal changes in testes size, fresh and post-thawing semen characteristics, serum testosterone level, and phospholipase a2 activity in gurcu male goats

Abstract

The aim of current investigation was to evaluate seasonal changes in the testicular measurements, fresh and post-thawing spermatological characteristics, serum testosterone (T) levels in Gurcu goats. Moreover, seminal plasma phospholipase A(2) activity levels were determined. Four adult Gurcu male goats (2-3 years old) were used as semen donor and ejaculates (n=113) from these goats were weekly collected with artificial vagina in the presence of natural estrus or estrogened female fantom during breeding season (BS, September-February) and non breeding season (NBS, March-August), respectively. Moreover, jugular blood was collected and serums were separated to determine Testesterone level during BS and NBS. All andrologic parameters, except testes width (P<0.05), were not changed statistically during BS and NBS in Gurcu bucks. It was determined that ejaculate volume (1.27 +/- 0.05 vs 0.76 +/- 0.04mL; P=0.001), fresh progressive sperm motility (80.39 +/- 1.00 vs 74.43 +/- 2.26%; P=0.019) were significantly higher in BS compared to NBS, respectively. However, sperm concentration (3.93x10(9) vs 2.48x10(9) spermatozoa/mL; P=0.001) was interestingly higher during NBS compared with BS, although total number of sperms per ejaculate were similar during BS (3.03x10(9) spermatozoa/ejaculate) and NBS (2.93x10(9) spermatozoa/ejaculate), P>0.05. Also there was no differences in post-thaw progressive sperm motility between BS and NBS (25.0 +/- 2.86 vs 19.32 +/- 2.55%; P=0.145). T did not any show significant change between BS and NBS (13.44 +/- 2.37 vs. 13.06 +/- 1.18 ng/mL). Although seasonal changes were observed in andrologic parameters, fresh and post-thawing spermatozoa in Gurcu bucks, this effect was limited.