First, the characteristics of green aquatic feed additives should have
1. It can promote the growth of aquatic animals, effectively and economically improve the production performance of aquatic animals, improve the utilization rate of feed and the quality of aquatic products, and has high aquaculture efficiency.
2. It can enhance the immune function of aquatic animals, prevent infectious diseases of aquatic animals and adjust the physiological function of the body.
3. No residue after use, does not affect the quality of aquatic animal products, does not affect the human living environment and health.
4. Physicochemical properties or biological activity are stable, can effectively enter the gastrointestinal tract to play a role, does not affect feed palatability.
5. In combination with other drug additives, no or inconsistent incompatibility occurs, and bacteria are not susceptible to drug resistance.
6. The scope of safety is relatively large and long-term use has no toxic side effects on aquatic animals.
Second, green aquatic feed additives and their applications
1. Viable preparations Viable preparations are bacterial preparations produced by industrialized anaerobic fermentation of animal beneficial bacteria. The mechanism of action of live bacterial preparations on aquatic animals can be briefly summarized as follows: When beneficial microorganisms in live bacterial preparations enter aquatic organisms, they form dominant bacteria groups, compete with harmful bacteria for oxygen attachment sites and nutrients, and competitively inhibit the growth of harmful bacteria. In order to regulate the intestinal flora to normalize; microbial metabolism to produce organic acids, lower intestinal pH, kill acid-resistant harmful bacteria; produce lysozyme, hydrogen peroxide and other substances, can kill potential pathogens; produce each Digestive enzymes are conducive to nutrient decomposition; synthesis of B vitamins, amino acids, unknown growth factors and other nutrients; direct stimulation of intestinal immune cells and increase local immune antibodies, enhance the body resistance to disease. Viable preparations used in aquaculture are characterized by the following three aspects: The first is the functional diversity, which has a growth-promoting effect and increases the production of aquatic products such as fish, shrimp, and crab. It has been reported that it can increase production. ~30%; improve the quality of aquatic products; have many functions such as disease prevention and disease resistance. Can improve the survival rate of 5 to 20% of the species; the second is a wide range of adaptability, the existing viable strains of aquatic products in Sichuan, Liaoning, Guangdong and other places to demonstrate, have shown significant results. The main reason is that it is mainly affected by the living environment of individual aquatic organisms, and the influence of the external environment on its role is relatively small. At present, there are only a few reports on living bacterial preparations for shrimps and fishes at home and abroad; the third is highly safe. Most live aquatic preparations are separated and purified from the microbial system in healthy aquatic animals, and then they are used in aquatic products. Animals do not cause any harm to aquatic animals, nor do they have residues in water and fish.
2. The glycosaminoglycans are natural bioactive substances composed of sugars (≥30%), glycosides (≥30%) and organic acids. The effective components of glycocalyx are stable in performance, safe to use, and have no compatibility with other feed additives. The amount of sugar hirudin added in the feed is 200-500 g/ton. It can completely replace the antibiotics, and it has no residues, does not pollute the environment. After feeding, it can significantly enhance the immunity and disease resistance of aquatic animals. Promote growth, increase daily gain and feed conversion rate, and have anti-stress and anti-oxidation effects; at the same time, it has a strong preventive effect on intestinal bacterial diseases. According to experiments, the quality of aquatic products fed with glycogen-based feed additives has been improved, meeting the green production requirements for animal-derived foods, and the social and economic benefits are significant.
3. Oligosaccharide oligosaccharides, also known as oligosaccharides, are a general term for oligomers having a straight chain or branched chain structure formed by linking 2 to 10 sugar groups through glycosidic bonds. There are many types of oligosaccharides, but currently used as feed additives mainly include: isomaltose, isomaltose, isomaltose, panose, oligotriose, oligotetraose, oligopentaose, and galacto-oligosaccharides. , mannooligosaccharides, soybean oligosaccharides, gentian oligosaccharides, xylo-oligosaccharides, and the like. Oligosaccharides can selectively promote the proliferation of beneficial bacteria in the gut of aquatic animals. These beneficial bacteria use oligosaccharides to produce short-chain fatty acids, lower intestinal pH, inhibit pathogenic bacteria from consuming nutrients in the body, and reduce the production of toxic and pathogenic metabolites, thereby maintaining and improving the health of aquatic animals. Certain oligosaccharides can increase the body's immune response to drugs and antigens and increase the immunity of aquatic animals. Compared with viable preparations, oligosaccharides are more stable, have a high tolerance to harsh environmental conditions such as granulation, bulking, oxidation, storage and transportation, and can resist the inactivation of gastric acid and overcome the viable bacterial agents in the intestine. Determined the difficulties of planting. In addition to its non-toxicity and no side effects, despite its low production efficiency and difficult production, its development and application prospects in aquafeeds are still very promising.
4. Enzyme preparations Enzyme preparations are industrial products containing a single enzyme or mixed enzyme processed by a specific production process. At present, with the exception of phytase which has a single enzyme product, most of the remaining enzyme preparations are compound preparations containing multiple enzymes. There are more commonly used cellulase, β-glucanase, xylanase, amylase, protease, pectinase, phytase and so on. Some of these enzymes can be secreted by themselves, such as amylase and certain proteases, while others cannot be secreted by themselves, such as cellulase, β-glucanase and xylanase. Enzyme preparations can destroy plant cell walls by breaking down substances made of non-starch polysaccharides (NSPs), such as cellulose, hemicellulose, and pectin, and break down these unusable polysaccharides into small molecule sugars that can be digested and absorbed. Can expose cell wall protection starch, protein and other nutrients to make it more full of nutrients. Enzyme preparations can also reduce the viscosity of viscous chyme due to soluble NSP. Enzyme preparations can also destroy stable phytate phosphorus structures and increase the availability of phosphorus and other nutrients in feed. Feed enzyme preparations used in aquaculture mainly have four functions: promoting feed digestion and absorption, promoting food intake and growth of aquatic animals; improving digestive system function and certain anti-inflammatory effects; preventing and slowing the stress response of aquatic animals; Improve feed efficiency and reduce nutrient content in excreta.
5. Chinese Herbal Feed Additives In recent years, Chinese herbal medicine has attracted people's attention due to its non-resistance to drugs and drug residues, small side effects, significant effects, and abundant resources. Chinese herbal medicine contains nutrients such as protein, amino acids, vitamins, oils, resins, sugars, plant pigments, macronutrients, and various trace elements. It also contains large amounts of organic acids, alkaloids, polysaccharides, volatile oils, waxes, tannins, and some unknown substances. The growth-promoting active substance. According to another study, Chinese herbs also contain a variety of immunologically active substances. The role of Chinese herbal medicine additives in aquaculture is mainly manifested in the following four aspects: promoting the intake of aquatic animals (enhancement) and increasing feed intake; reducing the feed coefficient and increasing the rate of weight gain; preventing fish diseases and increasing the survival rate; Some mineral salt additives and vitamin additives.
6. Yeast cell wall Yeast cell wall is a brand-new natural green additive. Its product is egg-white yellow powder. It is a special by-product extracted from soluble substances during the production of brewer's yeast, mainly composed of β-glucan, mannooligosaccharide, The glycoprotein and chitin constitute about 85% of the dry weight of the cell wall. Studies have shown that yeast cell walls have the physiological effects of stimulating and enhancing immune function; maintaining the balance of live bacteria; controlling diseases. Aquatic animals not only face the stress of changes in the water environment, but also suffer from many common diseases. Routine disease prevention and control measures are limited. Adding low-dose yeast cell walls to aquafeeds can enhance fish, shrimp, clams and crabs. Such as resistance to various major diseases and environmental changes, improve survival. Healthy fish and shrimp feeding yeast cell wall can improve the survival rate of seedlings by 20%-40%, and increase the survival rate by 10%-20% during the growth period. Therefore, the use of yeast cell wall special feed is considered to be an effective means to enhance the resistance of aquatic animals to disease and promote growth.
7. Carnitine Carnitine, also known as carnitine, was originally found in muscle extracts by Krimberg and Gulewitsch in 1905. There are two variants of L-type and D-type carnitine, and only L-carnitine exists in nature. L-carnitine is a water-soluble compound that has a great effect on humans and animals and is a vital active substance required by living organisms. In recent years, some studies have been conducted at home and abroad on the effects of carnitine on the growth performance of aquatic animals. Most studies have shown that carnitine has the following four functions for aquatic animals: increasing the weight gain rate of aquatic animals; reducing the body fat of aquatic animals , Improve meat quality; Save feed protein, reduce feed coefficient, improve the survival rate of aquatic animals; Improve fish reproduction rate.
On May 29, 1995, the State Council promulgated the "Regulations on the Administration of Feed and Feed Additives", which made China's feed safety management work into the track of legal management. The Ministry of Agriculture, in conjunction with the implementation of management regulations, increased the use of feed and feed additives. Efforts should be made to investigate and punish illicit drugs and encourage and develop green feed additive products to replace antibiotics and other feed additives. This is of great significance in solving drug residues, protecting the environment and human health, and accelerating the export of aquatic products. However, under the current situation of the development of aquaculture in China, it is not realistic to completely replace the antibiotics in aquatic feeds with green aquatic feed additives. It takes a gradual process for antibiotics to exit the aquaculture industry's historical stage. It is believed that with the steady development of the aquaculture industry and the feed industry, the continuous improvement of aquatic animal nutrition theory, the general improvement of people’s living standards, and the continuous improvement of safety awareness, there will be more green aquatic feed additives that meet the needs of production and life. come out.
1. It can promote the growth of aquatic animals, effectively and economically improve the production performance of aquatic animals, improve the utilization rate of feed and the quality of aquatic products, and has high aquaculture efficiency.
2. It can enhance the immune function of aquatic animals, prevent infectious diseases of aquatic animals and adjust the physiological function of the body.
3. No residue after use, does not affect the quality of aquatic animal products, does not affect the human living environment and health.
4. Physicochemical properties or biological activity are stable, can effectively enter the gastrointestinal tract to play a role, does not affect feed palatability.
5. In combination with other drug additives, no or inconsistent incompatibility occurs, and bacteria are not susceptible to drug resistance.
6. The scope of safety is relatively large and long-term use has no toxic side effects on aquatic animals.
Second, green aquatic feed additives and their applications
1. Viable preparations Viable preparations are bacterial preparations produced by industrialized anaerobic fermentation of animal beneficial bacteria. The mechanism of action of live bacterial preparations on aquatic animals can be briefly summarized as follows: When beneficial microorganisms in live bacterial preparations enter aquatic organisms, they form dominant bacteria groups, compete with harmful bacteria for oxygen attachment sites and nutrients, and competitively inhibit the growth of harmful bacteria. In order to regulate the intestinal flora to normalize; microbial metabolism to produce organic acids, lower intestinal pH, kill acid-resistant harmful bacteria; produce lysozyme, hydrogen peroxide and other substances, can kill potential pathogens; produce each Digestive enzymes are conducive to nutrient decomposition; synthesis of B vitamins, amino acids, unknown growth factors and other nutrients; direct stimulation of intestinal immune cells and increase local immune antibodies, enhance the body resistance to disease. Viable preparations used in aquaculture are characterized by the following three aspects: The first is the functional diversity, which has a growth-promoting effect and increases the production of aquatic products such as fish, shrimp, and crab. It has been reported that it can increase production. ~30%; improve the quality of aquatic products; have many functions such as disease prevention and disease resistance. Can improve the survival rate of 5 to 20% of the species; the second is a wide range of adaptability, the existing viable strains of aquatic products in Sichuan, Liaoning, Guangdong and other places to demonstrate, have shown significant results. The main reason is that it is mainly affected by the living environment of individual aquatic organisms, and the influence of the external environment on its role is relatively small. At present, there are only a few reports on living bacterial preparations for shrimps and fishes at home and abroad; the third is highly safe. Most live aquatic preparations are separated and purified from the microbial system in healthy aquatic animals, and then they are used in aquatic products. Animals do not cause any harm to aquatic animals, nor do they have residues in water and fish.
2. The glycosaminoglycans are natural bioactive substances composed of sugars (≥30%), glycosides (≥30%) and organic acids. The effective components of glycocalyx are stable in performance, safe to use, and have no compatibility with other feed additives. The amount of sugar hirudin added in the feed is 200-500 g/ton. It can completely replace the antibiotics, and it has no residues, does not pollute the environment. After feeding, it can significantly enhance the immunity and disease resistance of aquatic animals. Promote growth, increase daily gain and feed conversion rate, and have anti-stress and anti-oxidation effects; at the same time, it has a strong preventive effect on intestinal bacterial diseases. According to experiments, the quality of aquatic products fed with glycogen-based feed additives has been improved, meeting the green production requirements for animal-derived foods, and the social and economic benefits are significant.
3. Oligosaccharide oligosaccharides, also known as oligosaccharides, are a general term for oligomers having a straight chain or branched chain structure formed by linking 2 to 10 sugar groups through glycosidic bonds. There are many types of oligosaccharides, but currently used as feed additives mainly include: isomaltose, isomaltose, isomaltose, panose, oligotriose, oligotetraose, oligopentaose, and galacto-oligosaccharides. , mannooligosaccharides, soybean oligosaccharides, gentian oligosaccharides, xylo-oligosaccharides, and the like. Oligosaccharides can selectively promote the proliferation of beneficial bacteria in the gut of aquatic animals. These beneficial bacteria use oligosaccharides to produce short-chain fatty acids, lower intestinal pH, inhibit pathogenic bacteria from consuming nutrients in the body, and reduce the production of toxic and pathogenic metabolites, thereby maintaining and improving the health of aquatic animals. Certain oligosaccharides can increase the body's immune response to drugs and antigens and increase the immunity of aquatic animals. Compared with viable preparations, oligosaccharides are more stable, have a high tolerance to harsh environmental conditions such as granulation, bulking, oxidation, storage and transportation, and can resist the inactivation of gastric acid and overcome the viable bacterial agents in the intestine. Determined the difficulties of planting. In addition to its non-toxicity and no side effects, despite its low production efficiency and difficult production, its development and application prospects in aquafeeds are still very promising.
4. Enzyme preparations Enzyme preparations are industrial products containing a single enzyme or mixed enzyme processed by a specific production process. At present, with the exception of phytase which has a single enzyme product, most of the remaining enzyme preparations are compound preparations containing multiple enzymes. There are more commonly used cellulase, β-glucanase, xylanase, amylase, protease, pectinase, phytase and so on. Some of these enzymes can be secreted by themselves, such as amylase and certain proteases, while others cannot be secreted by themselves, such as cellulase, β-glucanase and xylanase. Enzyme preparations can destroy plant cell walls by breaking down substances made of non-starch polysaccharides (NSPs), such as cellulose, hemicellulose, and pectin, and break down these unusable polysaccharides into small molecule sugars that can be digested and absorbed. Can expose cell wall protection starch, protein and other nutrients to make it more full of nutrients. Enzyme preparations can also reduce the viscosity of viscous chyme due to soluble NSP. Enzyme preparations can also destroy stable phytate phosphorus structures and increase the availability of phosphorus and other nutrients in feed. Feed enzyme preparations used in aquaculture mainly have four functions: promoting feed digestion and absorption, promoting food intake and growth of aquatic animals; improving digestive system function and certain anti-inflammatory effects; preventing and slowing the stress response of aquatic animals; Improve feed efficiency and reduce nutrient content in excreta.
5. Chinese Herbal Feed Additives In recent years, Chinese herbal medicine has attracted people's attention due to its non-resistance to drugs and drug residues, small side effects, significant effects, and abundant resources. Chinese herbal medicine contains nutrients such as protein, amino acids, vitamins, oils, resins, sugars, plant pigments, macronutrients, and various trace elements. It also contains large amounts of organic acids, alkaloids, polysaccharides, volatile oils, waxes, tannins, and some unknown substances. The growth-promoting active substance. According to another study, Chinese herbs also contain a variety of immunologically active substances. The role of Chinese herbal medicine additives in aquaculture is mainly manifested in the following four aspects: promoting the intake of aquatic animals (enhancement) and increasing feed intake; reducing the feed coefficient and increasing the rate of weight gain; preventing fish diseases and increasing the survival rate; Some mineral salt additives and vitamin additives.
6. Yeast cell wall Yeast cell wall is a brand-new natural green additive. Its product is egg-white yellow powder. It is a special by-product extracted from soluble substances during the production of brewer's yeast, mainly composed of β-glucan, mannooligosaccharide, The glycoprotein and chitin constitute about 85% of the dry weight of the cell wall. Studies have shown that yeast cell walls have the physiological effects of stimulating and enhancing immune function; maintaining the balance of live bacteria; controlling diseases. Aquatic animals not only face the stress of changes in the water environment, but also suffer from many common diseases. Routine disease prevention and control measures are limited. Adding low-dose yeast cell walls to aquafeeds can enhance fish, shrimp, clams and crabs. Such as resistance to various major diseases and environmental changes, improve survival. Healthy fish and shrimp feeding yeast cell wall can improve the survival rate of seedlings by 20%-40%, and increase the survival rate by 10%-20% during the growth period. Therefore, the use of yeast cell wall special feed is considered to be an effective means to enhance the resistance of aquatic animals to disease and promote growth.
7. Carnitine Carnitine, also known as carnitine, was originally found in muscle extracts by Krimberg and Gulewitsch in 1905. There are two variants of L-type and D-type carnitine, and only L-carnitine exists in nature. L-carnitine is a water-soluble compound that has a great effect on humans and animals and is a vital active substance required by living organisms. In recent years, some studies have been conducted at home and abroad on the effects of carnitine on the growth performance of aquatic animals. Most studies have shown that carnitine has the following four functions for aquatic animals: increasing the weight gain rate of aquatic animals; reducing the body fat of aquatic animals , Improve meat quality; Save feed protein, reduce feed coefficient, improve the survival rate of aquatic animals; Improve fish reproduction rate.
On May 29, 1995, the State Council promulgated the "Regulations on the Administration of Feed and Feed Additives", which made China's feed safety management work into the track of legal management. The Ministry of Agriculture, in conjunction with the implementation of management regulations, increased the use of feed and feed additives. Efforts should be made to investigate and punish illicit drugs and encourage and develop green feed additive products to replace antibiotics and other feed additives. This is of great significance in solving drug residues, protecting the environment and human health, and accelerating the export of aquatic products. However, under the current situation of the development of aquaculture in China, it is not realistic to completely replace the antibiotics in aquatic feeds with green aquatic feed additives. It takes a gradual process for antibiotics to exit the aquaculture industry's historical stage. It is believed that with the steady development of the aquaculture industry and the feed industry, the continuous improvement of aquatic animal nutrition theory, the general improvement of people’s living standards, and the continuous improvement of safety awareness, there will be more green aquatic feed additives that meet the needs of production and life. come out.