In my article in the last issue, I discussed the growing quantity of traditional coproducts and new, evolving products for the corn ethanol industry that are hitting the marketplace. In this article, I will focus on feed products generated from the growing soy processing industry.
1. Introduction
The soy processing industry is rapidly expanding in the U.S. and evolving beyond traditional vegetable oil and soybean meal production. Driven by demand for biodiesel, renewable diesel, sustainable aviation fuel (SAF) and global protein demand, several new crush facilities are coming online and producing more meal, as well as a wider array of feed coproducts. These include high-protein soybean meal, soy protein concentrates and isolates, soy hulls and novel fractionated streams.
In fact, between 2024 and 2030, there are seven new plants being developed which, once they are all online, will raise U.S. soy crush to nearly 2.8 million bushels per year — up from approximately 2.2 billion bushels prior to 2025 (Gerlt, 2025). The additional 0.6 billion bushels of soybeans that will be processed will drastically increase the quantity of soy products available for the livestock and poultry industries. These products play a critical role in linking oilseed processing with animal agriculture.
2. Production Pathways and Product Types
Soybeans are dried, cleaned, dehulled, flaked and roasted, and then either solvent-extracted or extruded-expelled. Traditional outputs include soybean oil and soybean meal (solvent extraction typically separates more of the oils from the soybean, and thus the resulting soybean meal will be lower in fat content compared to the extruding-expelling process). Advanced fractionation technologies now allow separation of protein, fiber and soluble components, generating differentiated feed products with targeted nutrient profiles. The most common types of fractionated products include soy protein concentrate and soy protein isolate.
3. Nutrient Composition and Variability
The chemical composition of soy coproducts varies depending on processing intensity (Tables 1 and 2). Traditional soybean meal contains approximately 44% to 48% crude protein, while high-protein meals can exceed 50%. Soy protein concentrates and isolates can reach 60% to 90% protein. Soy hulls provide highly digestible fiber for ruminants. Variability arises from soybean quality, soybean genetics, dehulling efficiency and heat treatment, which will ultimately impact amino acid availability and energy value.
4. Digestibility and Feeding Value
Soybean meal remains the benchmark protein for swine and poultry diets due to its high lysine digestibility. Ruminants benefit from both soybean meal and soy hulls for protein and fiber. Emerging soy coproducts may improve digestibility and reduce anti-nutritional factors, but additional feeding trials are required. All soy coproducts have been shown to be safe and cost-effective for use in aquaculture diets and pet food
5. Economic Considerations
Soy coproducts are often benchmarked against DDGS and corn (Table 3). SBM provides superior amino acid balance, while DDGS offers lower-cost energy and phosphorus (generally, DDGS is about half the price of soybean meal). Relative pricing is often evaluated on a pro-fat (protein + fat) basis, although some will use digestible lysine or metabolizable energy. For processors, coproducts represent a major revenue stream, especially as oil is directed toward fuel markets. Key drivers include protein value, digestibility, consistency and transportation costs.
6. Sustainability Considerations
Soy coproducts contribute to our integrated food-fuel-feed systems; in other words, they are key players in the circularity of agricultural systems. Efficient use of all fractions improves resource utilization and can reduce overall carbon intensity. However, nutrient management and land-use considerations remain important, especially manure application, soy agronomics, regenerative ag practices, etc.
7. Logistics and Handling
Soy products generally have better flowability characteristics than DDGS, but they still present challenges. Soy hulls have low bulk density, while fine meals, concentrates and isolates have very small particle sizes and can generate dust. Proper storage and handling are required to maintain quality, prevent dust explosions and prevent cross-contamination.
8. Research Needs
To optimize the use of soy products in livestock, poultry, fish and pet foods, more research should focus on digestibility of the new soy fractions, standardization of product definitions and compositions, real-time nutrient analyses and integration into precision feeding systems.
9. Conclusions
The soy processing industry is entering a new era of production growth and coproduct diversification. While soybean meal remains dominant, emerging products offer opportunities for improved performance and sustainability. Success will depend on consistency, research validation and effective communications with livestock producers — who are the ultimate end users.
Kurt A. Rosentrater, Ph.D., is a professor in the Department of Agricultural and Biosystems Engineering at Iowa State University, Ames. He can be contacted at karosent@iastate.edu or 515-294-4019.
References
Gerlt, S. 2025. Soybean Crush Expansion, 2025 Update. Available online: https://soygrowers.com/news-re...
U.S. Soybean Export Council. Animal Nutrition. Available online: https://ussec.org/why-choose-u...
Soya Aquaculture Alliance. Research. Available online: https://soyaquaculture.com/res...
Hill’s Pet Nutrition. Benefits of Soy in Pet Food. Available online: https://www.hillspet.com/pet-c...