De oiled distillers solubles offer flexibility, but not performance or efficiency gains, in steers fed forage-based diets
Despite its lower fat content, results from an Applied Animal Science study demonstrate that modifying the nutritional composition of a common feed ingredient does not provide additional energy value or digestibility compared with dry-rolled corn
Champaign, IL, March 30, 2026—A common byproduct of ethanol production is condensed distillers solubles (CDS), a liquid product that contains most of the oil and a portion of the protein from the corn, and is commonly added to livestock feed for both energy and protein. Recently, a market has emerged for the oil from CDS, meaning it is now commonly de-oiled. A new study in Applied Animal Science offers timely insight into how de‑oiled CDS performs as a replacement for dry‑rolled corn in forage‑based cattle diets. Bill Weiss, PhD, PAS, Dipl. ACAS, editor in chief of the journal, explained, “Feedstuffs can change because of new manufacturing processes, and research is needed to determine the nutritional value of the modified feed. This study, using a wide range of inclusion rates, evaluated the nutritional value of de‑oiled distiller solubles when fed to steers receiving a high‑forage diet. This study included both a production trial and digestibility measurements, which aid greatly in the interpretation of the results.”
The research team, led by Jim MacDonald, PhD, PAS (Department of Animal Science, University of Nebraska, Lincoln, NE, USA), noted that the evolving nature of condensed distillers solubles was central to the study’s design. “We wanted to understand how this newer product behaves in a forage‑based diet and whether it could serve as an effective replacement for dry‑rolled corn,” said MacDonald, “especially given the lower fat content after the oil is removed, which we suspected might improve performance.” The team emphasized that with more than a million tons of CDS produced annually in the United States as of 2024, understanding its feeding value is increasingly important for producers.
To understand the value for both cattle performance and forage digestibility, MacDonald and his team conducted two complementary experiments. In the first, 68 crossbred steers were fed diets containing 0% to 40% de-oiled CDS over 96 days to measure effects on performance. In the second, six steers with cannulas in their rumens were used to assess digestibility and fermentation changes across the same levels, compared with a control group fed only hay. Together, the trials provided a detailed look at how de‑oiled CDS interacts with both animal performance and rumen function.
Caption: A new study published in Applied Animal Science involved two complementary experiments to understand the value of de-oiled distillers solubles for both cattle performance and forage digestibility (Credit: Karla Wilke).
The performance trial showed that replacing corn with de‑oiled CDS did not improve average daily gain or final body weight. Dry matter intake peaked at 20% CDS inclusion, and feed efficiency was poorest at that same level. These results suggest that the energy value of de‑oiled CDS is lower than that of corn in growing diets, despite the reduced fat content that initially led researchers to hypothesize improved performance. “We expected that removing oil from CDS might reduce negative rumen effects and enhance growth,” explained coauthor Karla Wilke, PhD, PAS (Panhandle Research and Extension Center, University of Nebraska, Scottsbluff, NE, USA). “But the data indicate that CDS still doesn’t match the energy contribution of corn in forage‑based systems.”
The digestibility study provided additional clarity to their results. As CDS inclusion increased, intake of dry matter, organic matter, and fiber declined, though gross energy intake remained the same. Rumen fermentation patterns shifted in a way that mirrored starch‑based diets, indicating that CDS ferments similarly to corn, even if it does not deliver equivalent energy for growth. “The rumen data show that CDS behaves a lot like dry‑rolled corn in terms of fermentation profile,” said Wilke. “But, matching fermentation doesn’t necessarily mean equally matching performance.”
Together, the experiments show that although de‑oiled CDS can be incorporated into forage‑based diets without harming performance, it does not enhance growth or efficiency in comparison with corn. The team emphasized that as ethanol byproducts continue to evolve, ongoing evaluation will be essential to ensure that feeding strategies keep pace with changes in ingredient composition.
The article appears in the April issue of Applied Animal Science.
Notes for editors
“Growing performance and digestion parameters in steers fed increasing concentrations of de-oiled corn condensed distillers solubles in forage-based diets,” by K. H. Wilke, B. H. Hansen, G. E. Erickson, and J. C. MacDonald (https://doi.org/10.15232/aas.2025-02746), Applied Animal Science, volume 42, issue 2 (April 2026), published by FASS and Elsevier.
This article is openly available at https://doi.org/10.15232/aas.2025-02746.
To schedule an interview with the author(s), please contact Karla Wilke, PhD, PAS, at kjenkins2@unl.edu.
About Applied Animal Science
Applied Animal Science (AAS) is a gold open access, peer-reviewed scientific journal and the official publication of the American Registry of Professional Animal Scientists (ARPAS). In continuous publication since 1985, AAS is a leading outlet for animal science research and is indexed by Scopus and ESCI (Clarivate’s Emerging Sources Citation Index). The journal welcomes novel manuscripts on applied technology, reviews on the use or application of research-based information on animal agriculture, commentaries on contemporary issues, short communications, and technical notes. Topics that will be considered for publication include (but are not limited to) feed science, farm animal management and production, dairy science, meat science, animal nutrition, reproduction, animal physiology and behavior, disease control and prevention, microbiology, agricultural economics, and environmental issues related to agriculture. Themed special issues also will be considered for publication. www.appliedanimalscience.org
About the American Registry of Professional Animal Scientists (ARPAS)
The American Registry of Professional Animal Scientists (ARPAS) is the organization that provides certification of animal scientists through examination, continuing education, and commitment to a code of ethics. Continual improvement of individual members is catalyzed through publications (including the AAS journal) and by providing information on educational opportunities. ARPAS is affiliated with five professional societies: American Dairy Science Association, American Meat Science Association, American Society of Animal Science, Equine Science Society, and Poultry Science Association. www.arpas.org
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