Further Experiments on the Nutrition of Sledge Dogs.

Sledge dogs are still widely used as draught animals on polar expeditions despite the increasing use of mechanical transport. They live and thrive whilst kept continuously out of doors in all but the most extreme conditions. At the bases they are fed on a diet of seal or other raw meat, but during sledging journeys, when fresh meat may not be available, all dog food must be carried on the sledges or previously laid ahead of the parties in depots. For many years the standard British ration was 454 g (I lb)/ day of pemmican, a dehydrated concentrated food developed by Watkins (1932) for the British Arctic Air Route Expedition, but this diet has been considered unsatisfactory both in quantity and in quality (Bingham, 1941). Experiments on the nutrition of sledge dogs were conducted both in Britain and in Antarctica (Taylor, Worden & Waterhouse, 1959) and an assessment was made of dog pemmican, which consisted of approximately two-thirds protein and one-third fat. The ration of I lb/day was not sufficient to maintain the weight of tethered dogs, and a thiamine deficiency was demonstrated. Diarrhoea was usual, and faecal nitrogen excretion was 30 % of the amount ingested. Taylor et al. (1959) developed a new diet for dogs containing approximately 30 % protein, 40 % fat and 10 yo carbohydrate, to which were added 1-2 mg thiamine, 10 mg nicotinic acid, 3 mg riboflavin, 1000 i.u. vitamin A, 600 i.u. vitamin D, 20 mg calcium pantothenate and 0.4 mg pyridoxine for each I lb block. Feeding trials were conducted in Antarctica in 1957 and 1958, when the old diet (diet A)was compared with the new diet (diet B) and with a further slight modification of the new diet (diet C). The results of the experiments are reported in this paper.