Dietary supplementation of exogenous carbohydrase enzymes in fish nutrition: A review

Abstract

Abstract A current priority in the aquaculture industry is the replacement of fishmeal with alternative feedstuffs, including plant-based protein ingredients, to ensure its sustainability. However, most plant-based feedstuffs have a wide variety of anti-nutritional factors, which may impair nutrient utilization, interfering with fish performance and health. The use of exogenous enzymes as feed additives to improve nutrient digestibility of plant-based feedstuffs has been researched extensively in poultry and swine. In aquaculture, the use of phytase to improve phosphorus utilization has emerged quite readily. However, the use of carbohydrase enzymes has not been as nearly as common in aquatic species, despite their promising effects in improving nutrient digestibility by hydrolyzing non-starch polysaccharides present in plant feedstuffs. Based on the information gathered in this review, supplementation of exogenous carbohydrases to plant-based fish diets should improve nutrient digestibility and reduce nutrient excretion. On the other hand, the effects of exogenous carbohydrases on fish performance are still unclear due to the difficulty in cross-study comparisons. Overall, based on the information gathered in this review, it is clear that research on exogenous carbohydrase supplementation in aquaculture nutrition is not extensive. According to promising results and opportunities found in other non-ruminant animals, and favorable effects found in aquaculture species studied to date, it may be significant to increase research on this subject because it could be a useful tool to improve and sustain commercial aquaculture.