swine, soybeans, nutrition, economics factors
Agricultural and Biosystems Engineering
Soybeans are an important protein source for the swine industry. However, the nutritional and economics values of soybeans as swine feed are dictated by the method used in processing the raw soybeans. Most soybeans produced in the U.S. undergo oil extraction and heat treatment to produce soybean oil and a byproduct soybean meal which is marketed as a protein supplement containing approximately 44 to 48% crude protein and 1.0% residual oil. Other raw soybean processing methods exist. However, nutrients in soybeans processed by different methods are not utilized with equal efficiency by all classes of swine. Raw soybeans contain antinutritional factors including trypsin inhibitor, urease enzyme, and toxic hemagglutinin, all of which are destroyed by heat treatment under controlled conditions. Raw soybeans may be processed by moist heating (autoclave or steam processed), boiling, micronizing (microwave), extrusion, or roasting. The object of the various processing methods is to heat the raw bean to a temperature that is high enough to destroy the antinutritional factors. These methods, unlike the oil extraction procedures used in soybean meal production, allow the swine producer to benefit from the natural high oil content (18%) of soybeans. However, to date, only extrusion and roasting of soybeans are feasible on-farm processing methods. Depending on the class of swine that will use the processed full fat soybeans, your decision to use extruded or roasted soybeans is based on nutritional and(or) economic factors.
Extension Service, Cooperative, "Full Fat Soybeans for Swine" (1988). SDSU Extension Extra Archives. 39.