Immunocastration in donkeys: clinical and physiological aspects
The work was aimed to evaluate testicular alterations induced by administration of immunocastration vaccine in Donkeys. A total of 12 adult Donkeys from the Northeast breed of Brazil were randomly distributed into control group (CG; n = 04) and immunocastration group (IG; n = 08). Donkeys from IG received two doses of Bopriva ® administered in an 30-day interval (Days 0 and 30). Blood samples were collected for testosterone dosage in this 30-day interval, when donkeys were weighted and measured
... ighted and measured for testicular biometry (testicular volume and tone). At the end of the experiment (Day 120), all donkeys were subjected to surgical castration in order to obtain testicular samples for histopathological analysis and from epididymis for evaluation of sperm cells. There was no difference in live weight (P > 0.05) within CG and IG groups during the experiment, however testosterone concentrations in IG donkeys were significantly (P < 0.05) lower after 30 and 60 days after the first vaccine, remaining in such levels until the end of the experiment. The CG did not show variations in testosterone levels during the experiment. No evidence of functional sperm cells was found in testis of IG donkeys, despite normal gametogenesis in CG. Testis from IG donkeys showed alterations in consistency and volume, suggesting a degenerative process, further confirmed by typical histopathological alterations of such pathology. Donkeys from the CG did not display these alterations. In IG donkeys, the ductal lumen of the epididymis ductal was dilated, filled with proteinaceous and eosinophilous content alongside with acidofilous germ cells. Furthermore, azoospermia was found in 75 % of IG donkeys, while remaining animals showed extremely low sperm concentration and no visible motility. Finally, immunocastration is an effective approach for male donkey castration due to its low cost and ease execution with no interference on animal welfare principles.