Faculty of Veterinary Medicine University of Zagreb
Abstract
This study was carried out on six buffalo bulls (Bubalus bubalis) for a one-year period. Four bulls selected had good and two bulls (No. 321 and 323) had poor semen quality. All bulls were aged from 6-10 years. Scrotal circumference (SC) and sperm characteristics of both bulls were lower than healthy bulls, while dead sperm percentage and total sperm abnormalities were high. Overall seminal plasma testosterone was lower in these bulls, while oestrogen was lower in bull 323 and higher in 321. Histopathological studies of testes of bull 323 showed a 100% loss of germinal epithelium (DGEL) in all three regions of the right testis; however, it was 89.96% in left testis. DGEL in bull 321 was 35.88 % in right and 31.70% in left testis, with higher DGEL in the ventral part in both testes. Total and lumen diameter was greater (P<0.01) in the caudal region of the left epididymis. Epithelial height in the caput region of the left epididymis was higher (P<0.05) in bull 323 while in the corpus of the right epididymis in bull 321 DGEL correlated negatively (P<0.001) with sperm concentration (r = -0.98), progressive motility (r = -0.88) and oestrogen (r = -0.87), and correlated positively (P<0.001) with dead sperm percentage (r = 0.89), total sperm abnormalities (r = 0.99) and testosterone (r = 0.98). Epithelial height showed a negative correlation (P<0.001) with DGEL (r = -0.88) and seminal plasma testosterone (r = -0.87), while it was positive (P<0.001) with oestrogen (r = 0.89).Istraživanje je provedeno na šest bivola (Bubalus bubalis) tijekom jedne godine. U dva bivola (321 i 322) utvrđena je sperma loše kvalitete. U njih je također utvrđen manji opseg skrotuma i velik postotak uginulih i abnormalnih spermija. Koncentracija testosterona u njihovoj spermi bila je niža u odnosu na onu u zdravih životinja. Razina estrogena bila je niža u bivola 323, a viša u bivola 321. Histopatološkom pretragom tkiva testisa bivola 323 utvrđena je potpuna odsutnost germinativnog epitela u desnom testisu te 89,6 %-tna odsutnost u lijevom testisu. U bivola 321 gubitak germinativnog epitela iznosio je 35,88% u desnom i 31,70% u lijevom testisu, s većim stupnjem gubitka u ventralnim dijelovima testisa. Ukupni promjer i promjer lumena bio je veći u kaudalnom području lijevog epididimisa (P<0,01). Visina epitelnih stanica na području glave lijevog epididimisa bila je veća (P<0,05) u bivola 323. Gubitak germinativnog epitela u području glave desnog epididimisa bivola 321 bio je u negativnoj korelaciji (P<0,001) s koncentracijom sperme (r = -0,98), progresivnom pokretljivošću (r = - 0,88) i estrogenom (r = -0,87), a u pozitivnoj korelaciji (P<0,001) s postotkom uginulih spermija (r = 0,89), abnormalnih spermija (r = 0,99) i testosteronom (r = 0,98). Visina epitelnih stanica bila je u negativnoj korelaciji (P<0,001) sa stupnjem gubitka germinativnog epitela (r = -0,88) i testosterona (r = -0,87), a u pozitivnoj (P<0,001) s razinom estrogena (r = 0,89)
