Noninvasive monitoring of reproductive function by determination of faecal progestagens and sexual behaviour in a herd of Przewalski mares in a semireserve

Abstract

We examined the reproductive activity and sexual behaviour of a herd of Przewalski mares Equus ferus przewalskii Poljakov, 1881 that were born in zoos and lived in a semireserve since 1992 during five periods in 1995-1997 of 4-6 weeks each. Ovarian activity was detected by the analysis of faecal progestagens. In addition, behavioural detection of oestrus and continuous recording of the daily activity with a storage telemetry system were carried out and compared with the analytical data. Faecal 20α-hydroxypregnane analysis revealed ovarian activity to be 100% (April/May 1995), 25% (May/June 1996), 88% (October/November 1996), 63% (January/February 1997) and 100% (April/May 1997) of the mares sampled. Behavioural observations showed a seasonal pattern with maximal sexual interactions in April/May 1995/1997 and only few interactions in winter. Detailed activity records in individual animals revealed an oestrus related increase from 14 h/d to 15.6 h/d. Our results show a tendency of seasonality which support the view that Przewalski mares are seasonal breeders with sexual activity in spring and early summer. In May/June 1996 a dysregulation of reproductive activity associated with a persistent increase in locomotor activity occurred. We hypothesise external disturbances from a shooting yard close to the semireserve. Compared to behavioural observations, faecal progestagen analysis seem to be the most convenient method to investigate reproductive activity in free ranging Przewalski mares.