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

The dynamics of vaginal cell exfoliation (EVC) in the breeding season in go ats (Criollo x 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 behavi or. Estradiol-17 beta (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 par abasal cells. As expected, sexual behavior was absent after the treatment. The progestin administration reduced estrone serum levels and E-2 became un detectable. Present results show that E-1 is the main estrogen produced dur ing 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. Therefo re, EVC, being highly indicative of the effect of progestins, may be used a s a tool to detect the response to hormonal treatments in the goat. (C) 199 9 Elsevier Science B.V. All rights reserved.