ORIGINAL RESEARCH article
Front. Anim. Sci.
Sec. Animal Nutrition
Replacing highly degradable starch with soluble fiber reduces the accumulation of trans-10 C18:1 in continuous culture fermenters with a basal level of soybean oil
Louisa Koch
Brandon Koch
Thomas Jenkins
Wilmer Cuervo
Gustavo Lascano
Clemson University, Clemson, United States
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Abstract
Evaluation of starch degradability (ShD) as well as starch level in a ration is necessary for determining how a ration will affect performance in lactating dairy cows. Substituting soluble fiber for starch can yield different fermentation patterns yet still provide similar energy to the animal without compromising performance. The objective of this study was to determine the effects of replacing starch with beet pulp in high or low starch degradable diets with a basal soybean oil level on biohydrogenation, digestibility, and rumen fermentation in continuous culture fermenters. Treatments included two levels of starch degradability, high (HDS) and low (LDS), and four levels of soluble fiber (SF), low (LOW), medium low (MEDLOW), medium high (MEDHIGH), and high (HIGH). Continuous culture fermenters were randomly assigned to treatments in a 2 x 4 factorial design and ran for four 10 d periods with new inoculum used at the start of each period. Data were analyzed using the MIXED procedure of SAS with repeated measures in a model including the fixed effects of treatment and period as fixed effects and fermenter as a random factor. Digestibility coefficients (dC) for neutral and acid detergent fiber (NDF, ADF) were unaffected by ShD or SF inclusion in the diet. Acetate increased linearly as SF level increased, whereas butyrate and isobutyrate were linearly reduced with SF. Total lactate tended to be reduced with SF and was unaffected by ShD. However, a linear decrease in pH was observed with SF addition. Starch degradability did not affect outflow of C18:1 or C18:2, but significantly decreased trans-12 C18:1 outflow and increased trans-10, cis-12 CLA with HDS. Total outflow of C18:3 was quadratically increased by SF, but total unsaturated fatty acid outflow was unaffected. Addition of SF linearly decreased total trans C18:1 and trans-10 C18:1, exhibiting a positive effect in the culture. Biohydrogenation of C18:2 tended to decrease quadratically with SF addition. The results of this study suggest that replacing starch with SF can alter the outflow of biohydrogenation intermediates, particularly trans-10 C18:1, suggesting a possible positive effect on the culture in situations with a high risk for milk fat depression.
Summary
Keywords
Biohydrogenation, Continuous cultures, fatty acid, soluble fiber, soluble fiber.
Received
12 August 2025
Accepted
17 February 2026
Copyright
© 2026 Koch, Koch, Jenkins, Cuervo and Lascano. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Gustavo Lascano
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.