Oilseed meals—like soybean meal, canola meal, and sesame meal—are essential protein sources in livestock and poultry rations. These meals are produced by removing oil from the seed. How the oil is extracted plays a major role in determining the meal’s nutritional value, fat content, and feeding rates. The two primary methods used in the feed industry are solvent extraction and expeller pressing. While both produce reliable protein meals, they differ in processing technique and in how the final product performs in an animal’s diet.
Solvent-Extracted Oil Meals
Solvent extraction is the most common method in large-scale commercial oilseed processing. 95-98% of the world’s soybean meal is solvent extracted. Seeds are cracked, flaked, and treated with a food-grade solvent—usually hexane—to dissolve and remove the majority of the oil. The solvent is then evaporated off and recovered, leaving behind a meal that is typically low in residual fat, usually around 1–3%. Because so much oil is removed, solvent-extracted meals are known for having a higher protein concentration on a percentage basis. Table 1 shows a nutrient comparison of solvent extracted meals and expeller pressed meals. Solvent extraction is a more effective way to remove oil from an oilseed.
*Values are from Resaca Sun Products’ meals
These meals have a consistent nutrient profile, making them ideal for high-precision feed formulations. They are widely used in poultry, swine, and dairy rations where nutritionists need tight control over energy and protein levels. The downside is that the intensive processing and extremely low fat content can sometimes reduce palatability or energy density compared to less-processed meals.
Expeller-Pressed Oil Meals
Expeller pressing—also called mechanical pressing—uses physical force rather than chemicals to remove oil from seeds. While this method extracts most of the oil, it leaves a higher residual fat content, often ranging from 6–10% or more, depending on the type of seed and press efficiency. This additional fat results in higher energy in the meal, making expeller-pressed meals more appealing for animals that benefit from higher dietary energy, such as cattle, goats, broilers, pigs, and beef cattle.
Because the process relies on friction and pressure, temperatures can vary, and the meal often retains more of its natural aroma and color. Many producers and consumers consider expeller-pressed meals more “natural,” and they are commonly used in Non-GMO or chemical-free feed programs. However, because mechanical extraction is less complete, the protein percentage—though still high—is typically lower than that of solvent-extracted meals. For example, solvent extracted soybean meal ranges from 46-48% protein while expeller pressed ranges from 42-44% protein.
Key Differences in Feeding Applications
In practice, the choice between solvent-extracted and expeller-pressed meals depends on the goals of the ration. If the priority is maximum protein concentration, and cost efficiency, solvent-extracted meals are often preferred. On the other hand, if the target species benefits from higher fat intake, or the feed program emphasizes minimal processing or Non-GMO ingredients, expeller-pressed meals may be the better fit.
Conclusion
Both solvent-extracted and expeller-pressed oil meals are valuable tools in modern livestock nutrition. Solvent-extracted meals offer high protein concentration, uniformity, and cost efficiency, while expeller-pressed meals provide higher natural fat levels, increased energy, and a processing method preferred in many natural or Non-GMO feeding programs. Understanding the distinctions between these two types of meals allows nutritionists and producers to choose the option that best aligns with their animals’ needs and their feeding philosophy.
