AbstractsMedical & Health Science

Emergency feeding of reindeer occasionally becomes necessary due to deep snow or ice crust preventing the reindeer from reaching the vegetation on the ground. The artificial feed stuffs available are not optimal for reindeer in poor condition and adaptation problems may occur. The aim of this thesis was to compare emergency feeding strategies based on lichens and feed stuffs commonly available in practice. Seventy-two reindeer calves were kept outdoors and continuously followed by observing their behaviour and collecting physiological data. The reindeer were first fed insufficient amounts of a lichen-based diet, followed by one starvation day to mimic a feed emergency situation. Four feeding strategies were then applied and the adaptation of these calves was compared with a control group, which received the lichen diet ad libitum. The control group remained healthy and showed consistent behaviour throughout the experiment and a group fed the lichen diet, after the starvation day, quickly recovered. This may be related to a substrate specific group of lichen utilizing bacteria that was found in their rumens. The adaptation to diets based on commercial reindeer feed and silage resulted in initial problems with diarrhoea and malnutrition. Another symptom was "wet belly syndrome", which started during the restriction period and continued during feeding. The fluid making the reindeer fur wet was found to be of internal origin, but the disease was not linked to any specific diet. As feeding proceeded, the animals adapted to the commercial feed and their behaviour became similar to the control group. The adaptation was confirmed by increased concentrations of protein, urea and insulin in the blood plasma, higher counts of protozoa and concentrations of volatile fatty acids in the rumen and gains in muscle and fat depots. This thesis shows that collection of a wide range of physiological data, together with behaviour studies in animals kept under equal conditions was a suitable method to evaluate the adaptation of reindeer to emergency feeding. It became clear that the general condition of the animals, before the feeding started, as well as the diet composition, affected the ability of the reindeer to adapt to feeding.