Diets fed to nonruminant animals are composed mainly of feed ingredients of plant origin. A variety of antinutritional factors such as phytin, nonstarch polysaccharides, and protease inhibitors may be present in these feed ingredients, which could limit nutrients that may be utilized by animals fed such diets. The primary nutrient utilization-limiting effect of phytin arises from the binding of 6 phosphate groups, thus making the P unavailable to the animal. The negative charges allow for formation of insoluble phytin-metal complexes with many divalent cations. Furthermore, phytin and protein can form binary complexes through electrostatic links of its charged phosphate groups with either the free amino group on AA on proteins or via formation of ternary complexes of phytin, Ca(2+), and protein. The form and extent of de novo formation of binary and ternary complexes of phytin and protein are likely to be important variables that influence the effectiveness of nutrient hydrolysis in plant-based diets. Nonstarch polysacharides reduce effective energy and nutrient utilization by nonruminant animals because of a lack of the enzymes needed for breaking down the complex cell wall structure that encapsulate other nutrients. Enzymes are used in nonruminant animal production to promote growth and efficiency of nutrient utilization and reduce nutrient excretion. The enzymes used include those that target phytin and nonstarch polysaccharides. Phytase improves growth and enhances P utilization, but positive effects on other nutrients are not always observed. Nonstarch polysaccharide-hydrolyzing enzymes are less consistent in their effects on growth and nutrient utilization, although they show promise and it is imperative to closely match both types and amounts of nonstarch polysaccharides with appropriate enzyme for beneficial effects. When used together with phytase, nonstarch polysaccharide-hydrolyzing enzymes may increase the accessibility of phytase to phytin encapsulated in cell walls. The future of enzymes in nonruminant animal production is promising and will likely include an understanding of the role of enzyme supplementation in promoting health as well as how enzymes may modulate gene functions. This review is an attempt to summarize current thinking in this area, provide some clarity in nomenclature and mechanisms, and suggest opportunities for expanded exploitation of this unique biotechnology.

BOARD-INVITED REVIEW: opportunities and challenges in using exogenous enzymes to improve nonruminant animal production.

Effects of bioflocs on growth performance, digestive enzyme activity and body composition of juvenile Litopenaeus vannamei in zero-water exchange tanks manipulating C/N ratio in feed

Effects of different levels of soybean meal inclusion in replacement for fish meal on growth, digestive enzymes and transaminase activities in practical diets for juvenile tilapia, Oreochromis niloticus × O. aureus

Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives Improved environmental and economic sustainability based on increased efficiency of production continues to be realized As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs

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Achieving sustainable aquaculture: Historical and current perspectives and future needs and challenges

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

A 12-week feeding trial was conducted to investigate the effects of supplemental exogenous enzyme on growth performance in juvenile hybrid tilapia Oreochromis niloticus×O. aureus (18 g, average initial weight). A commercial enzyme complex (neutral protease, β-glucanase and xylanase) was included at the level of 0.0 (control group), 1.0 and 1.5 g kg−1 diet in three test diets. Each diet was fed to triplicate tanks of the juvenile three times a day at 4–6% of wet body weight, and each tank was stocked with 50 fish. The results showed that specific growth rate and feed efficiency ratio significantly increased (P 0.05). However, the ADC of dry matter in fish fed high supplementation (1.5 g kg−1) was significantly higher than the control and low supplementation (P<0.05). There were no significant differences in condition factor, whole body moisture, protein, lipid and ash among dietary treatments. Viscera ratio, hepatosomatic index and the liver lipid decreased significantly with increasing enzyme (P<0.05). Both protease and amylase activities in the intestine and the hepatopancreas of juvenile hybrid tilapia significantly increased (P<0.05) with increasing dietary enzyme levels. The results suggested that enzyme supplementation can significantly improve growth performance and feed utilization in juvenile hybrid tilapia.

Effects of exogenous enzyme supplementation in diets on growth and feed utilization in tilapia, Oreochromis niloticus x O. aureus

Four isonitrogenous (gross protein content 30%) and isoenergetic (gross energy content 15 kJ/g) diets were formulated to investigate the effects of inclusion of plant proteins on the hybrid tilapia (Oreochromis niloticus×Oreochromis aureus). The plant proteins tested were soybean meal (SBM), rapeseed meal (RSM), cottonseed meal (CSM), and peanut meal (PNM). In each diet, 30% of the protein was supplied by fish meal, and the rest of protein was supplied by the plant protein tested. Each diet was randomly fed to three groups of hybrid tilapia for 8 wk in a recirculating freshwater system. The results showed that the best performance in terms of final weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio were shown in diets SBM and CSM. Four parameters were significantly affected by dietary RSM (P 0.05). The highest activities of glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, and superoxide dismutase in the liver were observed in group SBM and the poorest in group RSM. The results show that 39% CSM may be included in the practical diets without inhibiting fish performance. Although the inclusion of 50% RSM resulted in significantly lower growth performance, it produced histopathological damage in the liver.

Effects of Four Vegetable Protein Supplementation on Growth, Digestive Enzyme Activities, and Liver Functions of Juvenile Tilapia, Oreochromis niloticus×Oreochromis aureus

Influence of practical diet supplementation with free d-methionine on the growth and body composition in tilapia oreochromis niloticus×o.aureus : influence of practical diet supplementation with free d-methionine on the growth and body composition in tilapia oreochromis niloticus×o.aureus

Shimei Lin

Papers

Effects of exogenous enzyme supplementation in diets on growth and feed utilization in tilapia, Oreochromis niloticus x O. aureus

Effects of Four Vegetable Protein Supplementation on Growth, Digestive Enzyme Activities, and Liver Functions of Juvenile Tilapia, Oreochromis niloticus×Oreochromis aureus

Influence of practical diet supplementation with free d-methionine on the growth and body composition in tilapia oreochromis niloticus×o.aureus : influence of practical diet supplementation with free d-methionine on the growth and body composition in tilapia oreochromis niloticus×o.aureus