With a greater ability to upcycle ethanol co-products into animal feed ingredients, companies are creating custom products and partnering with University of Illinois researchers to test for quality and digestibility.

In a recent study published in the Journal of Animal Science, University of Illinois researchers showed that a new high-protein dried distillers grains with solubles (DDGS) product from Marquis Energy has greater energy and protein digestibility than conventional DDGS, according to an announcement from the university.

“We’ve never seen a corn co-product with such a high energy concentration or amino acid digestibility,” said Hans H. Stein, professor in the department of animal sciences at Illinois and co-author on the study. “It’s clearly a high-value product.”

The novel high-protein DDGS product, branded ProCap DDGS, contains 48% crude protein -- far higher than conventional de-oiled DDGS, which the research team evaluated at 31% in a nutrient analysis of each ingredient. The novel high-protein DDGS also provided approximately 1,200 kcal of metabolizable energy per kilogram more than conventional DDGS, according to the analysis.

The study consisted of three experiments. In the first, the researchers evaluated the apparent and standardized ileal digestibility of crude protein and amino acids in three diets: novel high-protein DDGS, conventional de-oiled DDGS (also from Marquis Energy) and a nitrogen-free diet used to determine endogenous losses of amino acids and crude protein.

The researchers fed each diet to nine growing pigs for six days at three times the maintenance energy requirement.

On the fifth and sixth days, researchers collected ileal digesta and analyzed dry matter, crude protein and amino acids. As suggested by their nutrient analysis of the raw products, the researchers found that the novel high-protein DDGS contained more crude protein and amino acids than de-oiled DDGS, and the standardized ileal digestibility of nearly all amino acids was greater in the novel high-protein DDGS.

The second experiment focused on energy digestibility. In this case, the researchers evaluated three diets: corn, corn plus novel high-protein DDGS and corn plus de-oiled DDGS. Again, all diets were supplemented with vitamins and minerals as needed. The team fed each diet to 24 growing barrows for 13 days at 3.2 times the maintenance energy requirement. Researchers calculated digestible energy and metabolizable energy values for all diets by collecting feces and urine over a four-day period during the experiment.

“If you look at the energy, which is of very high value for producers, and you compare with corn, we had much greater energy concentration in the (novel high-protein DDGS), whereas conventional DDGS was lower than corn,” Stein said.

The third experiment evaluated phosphorous digestibility. Researchers fed 32 barrows novel high-protein DDGS or de-oiled DDGS with or without microbial phytase for 13 days. Researchers collected feces from day 6 to day 12 and found that phytase plus the novel high-protein DDGS increased the digestibility of phosphorus. However, without phytase, the phosphorus digestibility of the novel high-protein DDGS was lower than the de-oiled DDGS.

The three experiments confirm that the novel high-protein DDGS has greater amino acid digestibility and contains more metabolizable energy than de-oiled DDGS but has reduced phosphorus digestibility.

“The ethanol industry is clearly moving toward trying to separate the different streams that come out after fermentation so they can identify high-value, high-quality products. I think we’ll see even more innovation and new feed ingredients in the future thanks to more advanced technologies in ethanol plants,” Stein said.

Researchers include Minoy Cristobal, Jessica Acosta, Su A. Lee and Stein. The research was supported by Marquis Energy.