Use of Exogenous Fibrolytic Enzymes to Improve Feed Utilization by Ruminants

TLDR: In this article, the authors have demonstrated that supplementing dairy cow and feedlot cattle diets with fiberdegrading enzymes has significant potential to improve feed utilization and animal performance, mainly due to improvements in ruminal fiber digestion resulting in increased digestible energy intake.

Abstract: Research has demonstrated that supplementing dairy cow and feedlot cattle diets with fiberdegrading enzymes has significant potential to improve feed utilization and animal performance. Ruminant feed enzyme additives, primarily xylanases and cellulases, are concentrated extracts resulting from bacterial or fungal fermentations that have specific enzymatic activities. Improvements in animal performance due to the use of enzyme additives can be attributed mainly to improvements in ruminal fiber digestion resulting in increased digestible energy intake. Animal responses are greatest when fiber digestion is compromised and when energy is the first-limiting nutrient in the diet. When viewed across a variety of enzyme products and experimental conditions, the response to feed enzymes by ruminants has been variable. This variation can be attributed to experimental conditions in which energy is not the limiting nutrient, as well as to the activities and characteristics of the enzymes supplied, underor over-supplementation of enzyme activity, and inappro