Effects of replacing steam-flaked corn with malted barley in feedlot rations on intake and in vivo and in vitro ruminal fermentation characteristics

Authors: LOCKARD, CATHERINE - Former ARS Employee; BECK, MATTHEW - Texas A&M University; PROCTOR, JARRET - Texas A&M University; KASUSKE, ZACHERY - Former ARS Employee; Koziel, Jacek; MIN, BYENG-RYEL - Tuskegee University; SMITH, JASON - Texas A&M Agrilife; GOUVEA, VINICIUS - Texas A&M Agrilife

Submitted to: Applied Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2025
Publication Date: 11/22/2025
Citation: Lockard, C.L., Beck, M.R., Proctor, J.A., Kasuske, Z., Koziel, J.A., Min, B., Smith, J.K., Gouvea, V.N. 2025. Effects of replacing steam-flaked corn with malted barley in feedlot rations on intake and in vivo and in vitro ruminal fermentation characteristics. Applied Animal Science. 41(6):641-648. https://doi.org/10.15232/aas.2025-02736.
DOI: https://doi.org/10.15232/aas.2025-02736

Interpretive Summary: Mitigating methane emissions can limit the effects of climate change in the short term. Methane emissions from cattle digestive systems represent the largest U.S. anthropogenic source. Malted barley is a natural source of a chemical compound that may alter cattle digestion and subsequently reduce methane production when fed to cattle. However, the effects of feeding malted barley to finishing cattle on methane production is unknown. To answer this question, researchers from ARS (Bushland, TX); Texas A&M University; and Texas A&M AgriLife conducted trials to assess the efficacy of feeding malted barley to reduce methane emissions. Malted barley inclusion increased feed consumption. However, it was found that methane production was increased by as much as 23%. Based on these findings, feeding malted barley cannot be recommended as a methane mitigation strategy in cattle feeding.

Technical Abstract: Objective: The objective of this experiment was to determine how dietary inclusion of malted barley (MB) influences DMI and in vivo and in vitro ruminal fermentation characteristics. Materials and Methods: Eight ruminally cannulated steers were used in this experiment and fed high concentrate diets (7% roughage). This experiment implemented a replicated 4 × 4 Latin-square design, with 4 experimental diets based on MB inclusion level: 0% (0MB), 9.8% (10MB), 19.6% (20MB), or 29.5% (30MB) MB on a DM basis. Inclusion of MB primarily displaced steam-flaked corn in the rations. Before each period, steers were adapted to their treatment diets for 10 d, followed by 7 d where DMI was measured. Following the intake measurement period (d 18), ruminal fluid (2 L) was collected for assessment of 48-h in vitro gas production while incubating the same diet (2.5 g of DM per jar) that the steers were fed. The following day (d 19), ruminal fluid was collected at 0, 3, 6, 12, and 24 h after feeding, and ruminal pH, NH3 , and VFA concentrations were measured. Results and Discussion: Dry matter intake quadratically increased with increasing MB inclusion; steers fed MB had 12% greater intake relative to steers fed 0MB. With increasing MB inclusion, the acetate proportion of total VFA increased linearly, whereas the propionate pro[1]portion of total VFA decreased linearly. Accordingly, there was a quadratic increase in the acetate-to-propionate ratio with increasing MB inclusion. During the in vitro part of the experiment, increasing MB inclusion linearly increased 48-h gas and quadratically increased CH4 production. Implications and Applications: The current results demonstrate that feeding MB increased DMI and acetate-to-propionate ratios in vivo and increased in vitro CH4 production. Based on these results, feeding MB is not a valid CH4 mitigation option.