Xylanase supplementation in fish feed

Sammendrag

Plant ingredients have so far been the most cost efficient alternative for fish in the aquafeed industry. This has increased the dietary content of indigestible carbohydrates, including non-starch polysaccharides (NSP) which dilute the energy concentration of the feeds and reduces digestibility/bioavailability of nutrients. Enzymes that hydrolyse NSP (NSP-enzymes) for better digestibility and growth performance have been introduced in the swine and poultry industry, and have also been studied in some fish species. Xylanase, an NSP-enzyme that hydrolyse cell wall components in plant, efficiently reduce NSP content in plant ingredient. Xylanase are found in yeasts, fungi and bacteria that are present naturally in the gut of some herbivorous fish species, such as carp and tilapia. This enzyme is commercially available alone or in multi-enzyme complexes for use in pre-processing of ingredients/diets or supplementation of diets during feed production. Dietary supplementation of xylanase have improved protein utilization and growth in several fish experiment. In addition some studies have reported increased endogenous enzyme production or prebiotic effects on the intestinal microbiota, which may lead to improved growth and health. To our knowledge, no peer-review publications exist on the use of xylanase as a supplement in feeds for Atlantic salmon.