Effects of melatonin on seasonal physiology of red deer

M.W. Fisher, P.F. Fennessy and J.D. Milne

Invermay Agricultural Centre, Ministry of Agriculture and Fisheries, Mosgiel

Proceedings of the New Zealand Society of Animal Production. 1988, 48: 113-116

Aspects of seasonal physiology were monitored in red deer either untreated or treated with melatonin designed to advance the onset of the natural breeding season. Treated animals were implanted with melatonin at monthly intervals during December, January and February (adult stags and yearling hinds) or January and February (lactating hinds).

Rutting behaviour, antler casting and velvet antler regrowth occurred up to 2 months earlier in melatonin-treated stags, while mean calving dates were advanced by 11 d in both groups of treated hinds.

In yearling hinds, melatonin treatment advanced by about 1 month the phase of low growth which occurred in control hinds in autumn. However, treatment had little overall effect on live weight of yearling hinds or lactating hinds. Treated hinds moulted their red summer coats and grew lighter winter-like coats about 1 month earlier than untreated hinds. The growth rates of calves sucking melatonin-treated and untreated hinds were virtually identical.

These results indicate that melatonin treatment can advance several aspects of seasonal physiology in deer.

Keywords: NZSAPAB; Melatonin; red deer; early breeding; antlers; live weight; coats; calf growth

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Last Updated 18-03-1997