EFFECTS OF DIETARY CARBOHYDRATE, FAT AND PROTEIN ON GROWTH, BODY-COMPOSITION AND BLOOD METABOLITE LEVELS IN DOG

Six semipurified canned diets ranging in composition from 0-62% of energy from carbohydrate and from 20-48% of energy from protein were fed to female beagle dogs for 8 mo. Additionally, 3 commercial-type diets were also fed. The effects of these diets on growth, body composition and selected blood metabolite levels in the dogs were studied. The dogs readily consumed each of the 9 diets fed. The level of carbohydrate, fat or protein in the diet did not influence body weight gain during the 1st 16 wk nor was N balance affected by the diets. At the end of the 32 wk study, dogs fed the high-carbodydrate (62% of energy) diet contained less body fat, but an equal fat-free mass, than did dogs fed lower-carbohydrate (20-42% of energy) diets with a similar quantity of protein. Consumption of carbohydrate-free diets did not influence postprandial levels of circulating glucose or insulin in the dogs. Plasma cholesterol levels were elevated in dogs consuming the diets high in fat but plasma triglyceride levels were not influenced. Consumption of high-protein (46-48% of energy) diets elevated plasma urea N levels but had minimal influence on plasma amino acid levels. The general response of these young dogs was not markedly influenced by consumption of diets ranging from carbohydrate-free to high-carbohydrate and from adequate-protein to high-protein.