Over The Horizon

Rudolph in Rut

New Zealand's leading place in farmed deer research has attracted a Norwegian researcher with a similar interest -- reproduction in reindeer.

Professor Erik Ropstand, of the Norwegian College of Veterinary Medicine, has been visiting the deer group at AgResearch Invermay to find out more about their pioneering techniques in reproductive physiology.

Reindeer farming is very different to the intensive deer farming of New Zealand, and has cultural significance for the Laplanders of northern Norway. About 300,000 reindeer range freely, being handled only two or three times a year. The rest of the time they are simply shepherded to keep the herd together and to direct them to good pasture and water.

One big problem faced by reindeer herders at present is the effect that low bodyweight has on productivity. The herd's productivity is related to female bodyweight, and scientists are trying to address the problem of low female weights and high calf mortality. One of the main causes is that first-year animals mate in the autumn before they are fully grown, regardless of whether they are heavy enough. The result is that they simply don't have a chance to show catch-up growth in the cold, harsh winter and this affects both females and offspring. Many lighter calves die and, of those that survive, some fail to thrive.

Only the heaviest females should therefore be mated, but arranging that is difficult under the traditional herding system. Options might be to separate males from the herd or to manipulate reproduction and delay puberty until the following season, allowing the females to build up bodyweight.

To find a solution, more information is needed on reindeer reproduction, which is the area of Ropstad's research. Despite the differences between red deer and reindeer, there are reproductive similarities, and Ropstad is in New Zealand to learn more about cervine reproduction . As reindeer range free, it's difficult to study them in the field; their managed cousins are an easier option.