Roasted Soybeans Outshine Distiller Grains in Cattle Protein Study

Nebraska researchers have found that roasted soybeans and distiller grains can improve protein levels in corn silage-based cattle diets. Corn silage is a common foundation for growing cattle diets, but its low protein quality makes additional supplementation necessary. Erin Laborie, a Nebraska Extension educator with the University of Nebraska, Lincoln, explains that corn silage typically contains 6.5% to 8.5% crude protein, with most of it classified as rumen degradable protein (RDP). RDP is broken down in the rumen and used by microbes to produce microbial protein.

Rumen undegradable protein (RUP), on the other hand, passes through the rumen and is digested in the small intestine. Corn silage provides relatively little RUP, with only 16% of its crude protein classified as RUP. Distillers grains are often added to silage-based diets because they provide a higher proportion of RUP, with about 63% of their crude protein in the RUP fraction.

Researchers at the University of Nebraska, Lincoln recently evaluated raw, whole, and roasted soybeans against modified distiller grains in silage-based diets. The study found that heifers receiving modified distiller grains had the highest feed intake and weight gains, but those fed roasted soybeans showed improved feed efficiency.

The results indicate that soybeans can provide both protein and fat in growing-cattle diets. Roasted soybeans may offer an advantage because of their higher RUP content, while raw whole soybeans can also be considered when prices and availability make them competitive with distiller grains.