Interpretive Summary: Flaxseed meal and oat hulls supplementation: impact on predicted production and absorption of volatile fatty acids and energy from hindgut fermentation in growing pigs
By: Anne Wallace
In this study published in the January 2019 Journal of Animal Science, a corn-soybean meal-based pig-feed was supplemented with soluble and insoluble fiber. This was done by supplementing the feed with flaxseed meal (FM) and oat hulls (OH), respectively.
Feed that is high in fiber has been previously shown to reduce energy absorption in pigs, however the effects of different types of dietary fiber need to be more thoroughly investigated. Therefore, the goal of this research was to better understand how soluble and insoluble fibers may differently impact the production and energy absorption of volatile fatty acids (VFAs) within pigs’ digestive system.
A total of 12 barrows of similar weight were fed one of three diets over 16 days. The study was designed as a 2-period crossover, with 4 pigs chosen randomly for each treatment during each period. The diets were designed as follows: basal (control) diet without added FM or OH, basal diet with added FM (12%), and basal diet with added OH (10%). Fecal samples were collected from cannula ports with direct access to pigs’ ileum on days 15 and 16.
The method of in vitro fermentation was used to determine the VFA concentration produced by the collected ileal material. The VFA types studied included acetic acid, propionic acid, butyric acid and valeric acid. It was found that pigs fed soluble fiber (FM diet) had a significantly higher concentration of VFA compared to pigs fed insoluble fiber (OH diet) and control. Therefore, based on the authors’ predictive model, absorption was also reported to be greater for FM pigs. Additionally, it was determined that there was less digested energy from VFA in pigs fed the OH diet, compared to pigs fed the FM diet.
This small study’s results suggest that addition of soluble fiber FM to pig-feed may increase VFA production and provide higher digestible energy compared to a diet with added insoluble fiber from OH. However, the number of pigs used in this study was few, so repeated studies including more animals to replicate and confirm results is warranted.
To view the article, “Flaxseed meal and oat hulls supplementation: impact on predicted production and absorption of volatile fatty acids and energy from hindgut fermentation in growing pigs,” visit the Journal of Animal Science.