Effect of protein intake during training on biochemical and performance variables in sled dogs.
OBJECTIVE
To determine effects of protein intake on blood variables, plasma volume, and maximal oxygen uptake (VO2max) in sled dogs undergoing rigorous training.


METHODS
32 Alaskan sled dogs, between 2 and 6 years old.


METHODS
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. Maximal oxygen uptake was measured at 0 (before training) and 12 weeks. Body weight, protein and energy intake, plasma volume, PCV, hemoglobin concentration, and serum biochemical variables were measured at 0, 8, and 12 weeks.


RESULTS
Serum biochemical variables, PCV, and hemoglobin 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 throughout training, compared with dogs fed the other diets. At 12 weeks, dogs fed diets C and D had greater serum sodium concentration and hemoglobin 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.


CONCLUSIONS
Consumption of a diet with 18% dietary protein on an energy basis (3.0 g of protein/kg of 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.
Reynolds
A J
AJ
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA.
Reinhart
G A
GA
Carey
D P
DP
Simmerman
D A
DA
Frank
D A
DA
Kallfelz
F A
FA
D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D001798:Blood Proteins / Q000032:analysis; D001835:Body Weight; D004285:Dogs / Q000378:metabolism / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D004911:Erythrocyte Volume / Q000502:physiology; D005260:Female; D006400:Hematocrit / Q000662:veterinary; D006454:Hemoglobins / Q000032:analysis; D008297:Male; D010100:Oxygen / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011897:Random Allocation; D017695:Soft Tissue Injuries / Q000662:veterinary
D001798:Blood Proteins; D006454:Hemoglobins; D010100:Oxygen