Two studies were conducted using adult dogs to evaluate the effects of increasing the inclusion of soybean meal in an adult dog food on body composition, hematological, biochemical blood analyses and total tract nutrient digestibility.

Nutritionally complete and balanced diets were formulated with commercial-grade soybean meal to replace 0, 10, 20 or 30% of the protein provided by dried chicken protein resulting in final soybean meal inclusion of 0, 6, 11.5 and 17%, respectively. In study 1, diets were fed during a 24-week feeding trial using 36 female spayed adult hounds to evaluate food intake, BW, body composition and blood measurements. There were no diet-related differences in food intake or BW. Body composition responded in a quadratic manner to increased dietary soybean meal inclusion with the percentage of lean mass responding positively and absolute amounts of fat mass and percent body fat responding negatively. All diagnostic blood components remained within normal physiological ranges for healthy, adult dogs.

In study 2, diets were evaluated in a digestibility study using 12 adult dogs in a 4 x 4 Latin square design. Increased soybean meal inclusion was associated with linear increases in the digestibility of CP and fat, and CP retention. Linear reductions in fecal DM content and increased fecal output were noted with increased soybean meal inclusion. All diets were similar in DE and ME content, but a quadratic trend was noted with increased SBM inclusion when DE and ME were expressed per unit of metabolic body size.

Overall, it can be implied from these results that the partial replacement of dried chicken protein with soybean meal in a nutritionally complete and balanced diet does not compromise the nutritional status and long-term health of adult dogs.

Source:  M.F. Menniti et al., 2014. Effect of graded inclusion of dietary soybean meal on nutrient digestibility, health, and metabolic indices of adult dogs. J Anim Sci online, March 2014. doi: 10.2527/jas.2013-7226.