Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix

Simple Summary Cereal grains and their by-products incorporated into non-ruminant animal feeds contain non-starch polysaccharides and phytate, which are anti-nutritional factors. The animals' endogenous digestive enzymes do not break down non-starch polysaccharides and phytate. Thus, exogenous enzymes such as carbohydrases and phytase, are supplemented to increase dietary energy and nutrient availability, reducing dietary cost and improving growth performance. Nevertheless, recent studies reveal that the improvement in growth performance goes beyond the release of indigestible nutrients. The positive impacts extend to the intestinal microbiota, immune system, and antioxidant status. However, it is unclear whether the benefits of enzyme action can be translated into better animal growth on commercial farms that face environmental, immunological, and management challenges. In this review, we observed that the supplementation of carbohydrases and phytase under poor sanitary conditions aligns with the energy and nutritional valorization matrices. This suggests that enzymes have properties that promote overall intestinal health, because they expedite post-sanitary challenge recovery and, at the same time, maintain improved utilization of the nutritional matrix. Additionally, studies under commercial conditions demonstrate that matrices containing carbohydrases and phytase sustain the growth and general health of broiler chickens and pigs. However, future research is needed to determine the extent of energy and nutrient savings at the commercial farm level.Abstract This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.