Disease and mortality on red deer farms in NEW Zealand

A longitudinal observational study of 15 red deer farms was carried out in New Zealand for two years from March 1992. The deer were monitored for perf ormance and health problems, and farm management practices were recorded. N umbers at risk were 4683 hind-years. 2459 stag-years and 3202 weaner-years. The numbers of primiparous and adult hinds at risk of losing their progeny by weaning were 653 and 3364, respectively. Where possible, postmortem exa minations were carried out, and organs were sampled for histological and mi crobiological investigation. Rates of mortality varied with season with mos t stag and hind deaths in winter and weaner deaths in autumn and winter: Ov erall mortality rates were 1.77, 2.60 and 5.87 per 100 deer-years for hinds , stags and weaners, respectively. Malignant catarrhal fever accounted for 0.53 stag and 0.17 hind deaths per 100 deer-years at risk Misadventure, inc luding broken bones, accounted for 15.4 per cent of weaner mortalities, or 0.53 weaner mortalities per 100 weaner-three months in autumn. Yersiniosis was confirmed in 18.6 per cent of weaner deaths, or 1.09 weaners per 100 we aner-years during the first six months after weaning, but was also suspecte d but unconfirmed in a further 41 per cent of weaner mortalities. Overall, 17 per cent of yearling hinds, and 9.2 per cent of adult hinds lost their p rogeny between pregnancy diagnosis in June and weaning in March. One outbre ak of osteochondrosis was recorded. Mortality rates varied between farms an d many mortalities were preventable.