Exfoliative vaginal cytology and plasma levels of estrone and estradiol-17β in young and adult goats

Abstract

The dynamics of vaginal cell exfoliation (EVC) in the breeding season in goats (Criollo × dairy breeds) and its relationship with estrogen levels and sexual behavior in the peri puberal period (Group I) were investigated. In addition the influence of progestins on EVC and serum estrogens was studied in adult goats (Group II). Five (62.5%) of the animals from Group I showed an EVC congruent with an estral cycle, and presented typical estrus behavior. Estradiol-17β (E 2) was undetectable in most of the animals of this group. However, estrone (E 1) was found in the serum of all goats. Before Melengestrol acetate (MGA) treatment, animals of Group II showed different types of vaginal cells in the (EVC) and both E 1 and E 2 were detected in the serum. The progestin administration resulted in the predominance of parabasal cells. As expected, sexual behavior was absent after the treatment. The progestin administration reduced estrone serum levels and E 2 became undetectable. Present results show that E 1 is the main estrogen produced during the peripuberal period. It is also shown that EVC is highly indicative of the demonstration of cyclicity at the onset of the reproductive period. In the adult goat, EVC pattern was changed under the effect of MGA. Therefore, EVC, being highly indicative of the effect of progestins, may be used as a tool to detect the response to hormonal treatments in the goat.