Comparative fecal steroid profile during pregnancy, parturition, and lactation between natural fertilization and embryo transfer in ocelots (Leopardus pardalis)

Despite the invaluable role that assisted reproduction technologies (ARTs) play in conservation, pregnancy and parturition rates by embryo transfer (ET) are low for most endangered felids. Thus, efforts to expand the knowledge on pregnancy biology and ET are still required. In this context, we examined fecal sex steroid metabolites (i.e., estrogens, glucocorticoids, and progestogens) of eight ocelots submitted to natural fertilization (NF) and ET in 22 pregnancies (19 NF and 3 ET). Fecal samples were collected and assessed for each pregnancy from estrous cycle, pregnancy, and lactation, totaling 155 days. In short, progestogen levels remained high and unchanged (P 0.05) in progestogen levels from conception until parturition, with a significant decrease during pregnancy (480.72 ng/day; r2 = 0.81; P