The effects of exogenous fibrolytic enzymes on the in vitro release of xylooligosaccharides and monosaccharides varies across six varieties of wheat

Abstract

Wheat is a widely used cereal grain for pig and poultry feeds globally. Despite this, there are noticeable differences in its nutritive value, potentially due to varying characteristics like inherent non-starch polysaccharide (NSP) content and composition. Fibrolytic enzymes help degrade NSP and thereby improve feed efficiency in livestock. However, it has been suggested that these enzymes have different effects dependent upon the characteristics of the wheat variety used in a feed. This study investigated the efficacy of different enzyme-wheat variety combinations, by quantifying the release of NSP-derived xylooligosaccharides (XOS) and monosaccharides from six varieties of wheat (Maris Huntsman, Highbury, Paragon, Sinuelo, Chinese Spring and Pavon 76) over a 24 h in vitro incubation with commercially available fibrolytic enzymes (Econase XT, Econase MP1000 or Barley P700). Complete non-starch acid hydrolysis showed there were differences between varieties in their total monosaccharide contents (P < 0.001). There were significant wheat variety x enzyme x incubation time interactions for the release of xylobiose, galactose and glucose (all P < 0.001) and significant enzyme x wheat variety interactions for the release of xylotriose (P = 0.022), xylose (P < 0.001) and arabinose (P = 0.028). Clear differences in release of XOS were observed between the different combinations of enzyme and wheat variety. Econase XT increased xylotriose release from Highbury wheat, and xylobiose release from Sinuelo, with both wheat varieties showing comparable release of xylose. These findings suggest that the fibrolytic enzymes tested have some specificity for the wheat varieties. Hence it might be possible to optimise the combinations of wheat variety and enzyme used in animal feeds, to help maximise the feed efficiency of livestock.