MONITORING OF PROGESTERONE AND ESTRONE FECAL METABOLITES THROUGHOUT GESTATION IN EWES

Abstract The aim of this study was to monitor the progesterone and fecal estrone metabolites throughout gestation in ewes correlating with the serum levels of these steroid hormones. Therefore, fecal and serum samples were collected from 5 weeks before mating and gestation until two weeks postparturition. Serum levels of progesterone and estrone and their fecal metabolites were measured by enzyme immunoassay. Serum and fecal hormonal patterns showed a significant correlation for both hormones (R = 0.8572, P < 0.001 for progesterone and R = 0.5893, P < 0.001 for estrone). The fecal progesterone metabolite levels showed significant increasing values among the three thirds of pregnancies, consistent with the serum levels and with the literature. Additionally, the prepartum peak of estrone in the fecal matrix was identified but without observation in the serum matrix due to the blood collection interval used. Therefore, this study demonstrated the viability of progesterone and estrone monitoring throughout gestation using fecal samples, making noninvasive longitudinal endocrine monitoring throughout gestation possible in this species.