Dog Studies with Soy Protein

A study was conducted with dogs to determine whether textured soy protein would change the intestinal transit time of a meal going through the digestion track. Cannulated dogs were fed canned diets containing different amounts of textured soy protein or beef. Results indicated that as the level of textured soy protein was increased, the prececal digestion of protein and carbohydrate was reduced from 77 to 71 percent and 80 to 62 percent, respectively. The indigestible carbohydrates in the textured soy protein product reduced nutrient digestibility but had no affect on the rate of movement of intestinal contents to the ileum. Therefore, intestinal transit is not responsible for the lower nutrient availability of textured soy protein in dogs.

Hill, R.C. and co-workers. 2001. The effect of textured vegetable protein from soy on nutrient digestion compared to beef in cannulated dogs. J. Animal Sci. 79(8):2162-2171.