Four experimental formulations with varying WSB inclusion levels (0%, 10%, 20% and 30%) will be extruded to produce dry expanded kibbles that will be coated with standard poultry fat and palatant and used in a 2-week feeding trial with dogs. Extrusion processing parameters will be monitored and extruded kibble expansion properties will be measured. Raw material and finished product physico-chemical properties will be analyzed. Process stability will be determined. Dogs' body weight will be measured through the study. Fecal quality will be monitored. Hypotheses include the idea that whole soybeans may serve as an important source of protein and nutrition for pet diets and there is a potentially enhanced and new use and market for Kansas soybeans to drive return on investment for soybean farmers and further promote soybeans.

To determine the ideal extrusion processing conditions that eliminate antinutritional factors in whole soybean containing diets and optimize the prebiotic benefit for dogs. Specific objectives include: 1) Whole soybean characterization; 2) Optimizing extrusion parameters for 30% WSB-containing diet; 3) Optimization for trypsin inhibitor elimination in pilot-scale extruder; 4) Experimental diet production for food evaluation by dogs; 5) Evaluation of the maximum oil binding capacity; 6) Nutrient digestibility in dogs.

Science-based evidence that including WSB in extruded dog food does not negatively impact fecal quality, inclusion of WSB in extruded dog food is promising, as it may enhance nutrient digestibility in dogs without adversely affecting extrusion process stability, kibble quality, food intake, digestibility or fecal characteristics. Overall, this study strives to demonstrate a potential for substantial economic impact by increasing the usage of WSB in pet food.

Updated January 2, 2025:

Updated April 8, 2025:
Soy is a very nutritious ingredient due to their high levels of protein, fat and fiber. Previous studies have investigated the nutritional aspects of using soy (primarily as soybean meal) in pet food, however there is minimal research on use of whole soybeans (WSB) in pet food and the impact on extrusion processing, kibble quality and nutrient digestibility. This study examined ideal extrusion processing conditions for inclusion of up to 30% WSB in dog food diets, which not only lead to good physical quality of the kibble but also help eliminate anti-nutritional factors such as trypsin inhibitors and provide high nutrient digestibility, fecal quality and overall gut health for the animal. Four experimental formulations with varying WSB inclusion levels (0%, 10%, 20% and 30%) were extruded with a Wenger X20 single screw extruder to produce dry expanded kibbles that were coated with standard poultry fat and palatant and used in a 2-week feeding trial with dogs. Extrusion processing parameters were monitored and extruded kibble expansion properties were measured. Raw material and finished product physico-chemical properties were also analyzed. Extrusion specific mechanical energy decreased drastically for 30% WSB inclusion as compared to other WSB levels (212 kJ/kg versus 290-313 kJ/kg), which negatively impacted kibble expansion (482 g/L versus 364-381 g/L). Process stability was also drastically reduced on inclusion of 30% WSB. Dogs maintained body weight through the study and no differences in food intake were observed irrespective of the level of WSB inclusion (0-30%). Fecal quality was not majorly affected either by WSB inclusion, although at 30% WSB greater fecal volume, moisture content and fecal ammonia content was observed. A quadratic effect was observed for the digestibility of dry matter, organic matter, crude protein, fat and gross energy with the increasing level of WSB, with digestibility of macronutrients and energy only negatively impacted when WSB was included at 30% that aligned with the high fecal volume. However, inclusion of WSB at levels up to 20% in extruded dog food appeared promising, as it may enhance nutrient digestibility in dogs without adversely affecting extrusion process stability, kibble quality, food intake, digestibility or fecal characteristics. The study results have a potential for substantial economic impact by increasing the usage of WSB in pet food.

Enhance and develop uses and markets for Kansas soybeans, support soybeans as pet food components, and promote the soybean industry.