Enzyme preparation is a kind of feed additive widely used in feed in recent years. As the enzyme preparation can effectively improve the utilization rate of the feed, save the raw material resources of the feed and has no side effect, it becomes an environment-friendly green feed additive. At present, thousands of enzymes have been found, more than 300 of them can be produced artificially, and more than 20 of them can be used in feed industry.
1、Definition and Classification of Feed Enzymes
Feed enzyme preparation is a kind of feed additive produced by one or more enzymes produced by bioengineering technology, carriers and diluents through a certain processing technology.
Feed enzymes can be divided into exogenous enzymes and endogenous enzymes according to whether they are secreted in large quantities in animals. Exogenous enzymes include phytase and non-starch polysaccharidase, which can not be secreted by animals themselves. The non-starch polysaccharide enzymes include xylanase, β-glucanase, mannanase, pectinase and cellulase. Endogenous enzymes include protease, amylase, lipase and so on.
According to the types of enzymes contained in the products, feed enzyme preparations can be divided into single enzyme preparations and complex enzyme preparations. Wherein the complex enzyme preparation is formed by mixing one or more single enzyme preparations as a main body and other single enzyme preparations, or is obtained by fermentation of one or more microorganisms. The complex enzyme can degrade a plurality of substrates which need to be degraded in the feed at the same time, and can improve the nutritional value of the feed to the maximum extent.
2、Function of Feed Enzyme Preparation
As a feed enzyme preparation with dual characteristics of nutritional additives and non-nutritional additives, it has been expanded from the original nutritional function of improving the digestion and utilization of dietary nutrients to a variety of functions including regulating animal intestinal health, sterilization and bacteriostasis.
2-1 Eliminate anti-nutritional factors
Anti-nutritional factors (proteins, non-starch polysaccharides and phytic acid) in feed will produce viscosity when they enter the digestive tract, which will hinder the contact between digestive juice and feed and reduce the digestibility of feed. The addition of non-starch polysaccharide enzymes in feed can reduce the intestinal viscosity of feeding animals, thereby improving the digestion and absorption of nutrients. In addition, trypsin inhibitors and plant lectins can also destroy plant cell walls and eliminate protein antinutritional factors.
2-2 Improve the intestinal environment
After soluble non-starch polysaccharides are dissolved, chyme gel will form large groups, which will hinder the contact between feed nutrients and digestive juice, thus reducing the feed intake of animals and hindering the flow and absorption of nutrients. The non-starch polysaccharide enzyme can increase the activity of proteases in the hepatopancreas, stomach and intestine of fish. Glucanase can increase the activities of proteinase and amylase in intestinal chyme and tissues. The increase of digestive enzyme activity promotes the digestion and absorption of nutrients by economic fish, reduces the retention time of chyme in the digestive tract, reduces the intestinal flora, and accelerates its growth.
2-3 Supplement endogenous enzymes
In the young stage of animals, the development of digestive system is not perfect, and the secretion of digestive enzymes is small, but a large number of nutrients are needed to meet the growth needs, and then exogenous digestive enzymes need to be supplemented. Therefore, the physiological characteristics of animals at this stage should be combined to supplement digestive enzymes, including protein enzymes and amylase, in order to meet the physiological needs of feeding animals, maintain the health of the body and maintain a higher level of production performance.
3、Market Prospect of Feed Enzyme Preparation
In 2021, the total output of industrial feed in China was 293,443,000 tons, which was converted into complete formula feed with a total 629,834,000 tons. At present, the proportion of feed added with feed enzyme preparation in China is 80%, and the annual market demand for feed enzyme preparation in China is about 176,000 tons if the amount of enzyme preparation added in complete formula feed is calculated as 0.035%. With the growth of China’s feed industry and the limited use of antibiotics, enzymes are considered to be one of the functional additives to replace antibiotics, and the market demand will continue to increase in the future.