Oral presentation- Workshop 12th International Mammalogical Congress

Gas chromatography mass spectrometry (GCMS): An alternative method to evaluating bioindicators in non-invasive samples from wildlife species (#170)

Martin Dehnhard 1
  1. Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany

Understanding the basics of reproductive endocrinology of animals is vital for their conservation and management. Non-invasive analyses of hormone metabolites in urine or faeces represent reliable methods for monitoring endocrine activities. Alternatively, semiochemicals carrying information for conspecifics, such as estrus signalling substances for example, could be used as indicators to detect estrus. Immunoassays (EIA) relying on antibodies against individual hormones are widely used for hormone metabolite profiling. An alternative analytical technique is gas chromatography-mass spectrometry (GC-MS). Contrary to EIAs, GCMS analyses allows the quantification of numerous compounds in a single run. As solitary living individuals, giant pandas (Ailuropoda melanoleuca) use olfactory cues (i.e. in urine) to mediate mating-related social interactions. In ex-situ panda breeding, urinary steroids serve as estrous indicators. Using GCMS we analysed urinary steroid profiles as well as urinary volatiles that adsorb on polydimethyl-siloxane (PDMS) tubes. When profiling urinary steroid metabolites, peak levels of estrone-sulfate were confirmed on the day prior to ovulation. Major gestagen metabolites found were 5a/b-pregnane-3a-ol-20-one and pregnanediol. Both metabolites are products of deviating metabolic routes; however, no difference in progestagen composition was found between pregnant and pseudopregnant pandas. Analyses of PDMS adsorbed urinary volatiles revealed an abrupt increase of fatty acids to peak levels 6 days prior to ovulation that had been used for an early ovulation prognosis in one panda. Moreover, we recommend the PDMS technique e.g. to compare odour profiles from scent gland secretions between individuals of different social status as basis for semiochemical-based environmental enrichment to enhance animal welfare in captive populations