Effect of protein intake during training on biochemical and performance variables in sled dogs
Reynolds, A.J.; Reinhart, G.A.; Carey, D.P.; Simmerman, D.A.; Frank, D.A.; Kallfelz, F.A.
American Journal of Veterinary Research 60(7): 789-795
1999
ISSN/ISBN: 0002-9645 PMID: 10407468 Document Number: 498082
The effects of protein intake on blood variables, plasma volume and maximum oxygen uptake (Vo2max) was studied in 32 Alaskan sled dogs undergoing rigorous training. Dogs were assigned to 1 of 4 groups on the basis of age, sex and ability. Isocaloric diets containing 18% (diet A), 23% (diet B), 29% (diet C) or 35% (diet D) of energy as protein were assigned randomly to each group and fed 1 month before and during a 12-week training period. Maximum oxygen uptake was measured at 0 (before training) and 12 weeks. Body weight, protein and energy intake, plasma volume, packed cell volume (PCV), haemoglobin concentration and serum biochemical variables were measured at 0, 8 and 12 weeks. Serum biochemical variables, PCV and haemoglobin concentration remained within reference ranges for all dogs. Dogs fed diet A had a decrease in Vo2max and a greater rate of soft tissue injury through-out training, compared with dogs fed the other diets. At 12 weeks, dogs fed diets C and D had greater serum sodium concentration and haemoglobin concentration than did dogs fed diet A. Dogs fed diet D also had more plasma volume at 12 weeks than did dogs of any other group. It is concluded that consumption of a diet with 18% dietary protein on an energy basis (3.0 g of protein/kg body weight) is insufficient to meet the metabolic requirements of sled dogs in training. For intense interval work, a diet with 35% dietary protein as energy (6.0 g of protein/kg) may provide a performance advantage by promoting an increase in plasma volume.