FECAL STEROID ANALYSIS FOR NONINVASIVE MONITORING OF REPRODUCTIVE STATUS IN FARM, WILD AND ZOO ANIMALS

Non-invasive faecal oestrogen and progesterone metabolite evaluations are well established approaches for monitoring reproductive function i n a variety of mammalian species. The route of excretion of steroid ho rmone metabolites varies considerably among species, and also between steroids within the same species. Steroid concentrations in faeces exh ibit a similar pattern to those in plasma, but have a lag time, which depending upon the species, can be from 12 h to more than 2 days. Faec al steroid metabolites in mammals are mainly unconjugated compounds, F aecal oestrogens consist predominantly of oestrone and/or oestradiol-1 7 alpha or -17 beta. Therefore, specific oestrogen antibodies or antib odies against total oestrogens can be used for their determination. Pr ogesterone is metabolised to several 5 alpha- or 5 beta reduced pregna nediones and hydroxylated pregnanes prior to its faecal excretion. The refore, relevant antibodies for their determination show considerable cross-reactivities with several pregnane metabolites, whereas specific progesterone antibodies are less suitable. Faecal oestrogen evaluatio ns have been used as reliable indicators of pregnancy in several ungul ate and some primate species. They have also been used to determine th e preovulatory period in carnivores, corpus luteum activity in New Wor ld primates, and to diagnose cryptorchidism in horses, Faecal progeste rone metabolite analysis has been successfully used for monitoring cor pus luteum function and pregnancy, abortion, seasonality and treatment therapies in an ever expanding list of species.