Interpretive Summary: Degradation of dietary fiber in the stomach, small intestine, and large intestine of growing pigs fed corn- or wheat-based diets without or with microbial xylanase.
By: Anne Wallace
Arabinoxylans are indigestible fibers found in grain products, including corn and wheat. The enzyme xylanase, derived from microbes, aids in the digestion of xylan fibers. In this paper published in the January 2019 Journal of Animal Science, researchers evaluated how adding microbial xylanase to pig feed impacted the digestibility of wheat- and corn-based diets.
Twenty-four barrows were fed one of 12 different diets for 18 days, over 4 periods. The diets included: (1) a corn and soybean meal (SBM) diet, (2) a corn, SBM and 30% distillers dried grains with solubles (DDGS) diet, (3) a wheat and SBM diet, and (4) a wheat, SBM and 30% wheat middlings diet. Each of the four diets were prepared without any microbial xylanse, with microbial xylanase A, or with microbial xylanase B.
Fecal samples were collected from T-cannula ports allowing direct access to and collection of fluid from both the proximal duodenum and distal ileum. Analysis indicated that apparent duodenal digestibility (ADD) and apparent total tract digestibility (ATTD) were significantly increased in wheat diets with added xylanase A and B. Digestible energy (DE) and metabolizable energy (ME) concentrations were also significantly increased in the wheat, SBM and 30% wheat middlings diet with added xylanase A. Addition of xylanse B also improved DE concentration in the wheat-containing diets, and ME in the wheat and SBM diet.
The results of this small study suggest that addition of microbial xylanase may have the potential to improve digestibility of wheat-based diets in pigs. This conclusion is supported by increased digestibility of wheat-based pigfeed with added xylanase, compared to the corn-based diets. Larger studies to reconfirm these findings, and to also better understand the comprehensive effects of xylanase on arabinoxylans in the hindgut of pigs may be warranted.
To view the article, “Degradation of dietary fiber in the stomach, small intestine, and large intestine of growing pigs fed corn- or wheat-based diets without or with microbial xylanase,” visit the Journal of Animal Science.