I. Sources and Basis of Compound Feed Formula In the past, we used more than three aspects in formulating the source of certain marine fish:
The first is the conversion from the eel's bait; the second is that some formulas introduced into Japan are slightly improved; the third is to adjust the formula of the shrimp bait. The above three aspects all have serious maladies in the aspects of fish nutrition and physiology and ecology, especially in the composition of premixes. There is a wide variety of differences. As a result, the fish that are raised do not know why it is good and the bad is not We know why everyone knows that carp is a freshwater fish. Its nutrient composition is based on principles suitable for freshwater fish. If this kind of powdered carp material is used to raise seawater fish, it will fundamentally violate the ecological environment. It is not effective. There is also a big difference in the formulation of certain fishes in Japan. Today, Japan mainly breeds cold-temperate and oceanic fish such as salmon, whale, squid, and flounder. In the southeast coast of China, mainly grouper, whale, black shark, true shaw, big yellow croaker and red silk are cultured. These fishes are not only different in ecological environment, but also have different feeding habits and natural foods. If the Japanese formula is used to breed our country, Fish species will also increase the cost just like taking Japanese shrimp feed to raise Chinese shrimp. Reduce efficiency. If the saltwater fish feed is improved from the shrimp feed, the proportion of nutrients caused by the natural food from the fish and shrimp is different or secondary, which is the biggest problem in the formulation of the premix. Because shrimp is a vertebrate animal, blood does not contain hemoglobin and haemoglobin is contained in the blood, and the regulation of seawater osmotic pressure is "because of degeneration", while the blood and tissue components of marine fish are "self-discipline" in the regulation of osmotic pressure in external water. The change of this physiological mechanism affects the absorption of different ions in the digestive system and the excretory function of the phlegm and kidneys. There is a very complicated relationship between biochemical transformations. Therefore, it is unscientific to simply make simple changes to the formula of shrimps as a formula for breeding marine fish.
In order to increase the production of marine fish, it is necessary to deeply study the specific bait of a certain type of fish so that it contains the nutrients and energy substances needed for the growth, reproduction, and health of the fish, and its insufficient content causes the fish to grow slowly or develop diseases. In some cases, overnutrition also affects fish growth. Therefore, the nutrition of marine fish also needs energy, protein, fat; sugar. Vitamins and minerals, etc. are composed of several aspects, after the test data, and then according to their ecological habits, the design of the food formula is scientific and reasonable.
Protein, Fat, and Sugar Requirements Proteins, fats, and sugars are indispensable nutrients for fish nutrition. In addition to the actual experimental requirements for each fish, we should also understand that fish of different ecological habits are of the same type. Different ways of using materials. For example, when raising the proportion of algae in the diet of sweetfish and black shark (due to the high sugar content of algae), the fat content in the muscles of sweet fish is reduced, but the fat in the muscles of black silk is actually increased. The formulation is contradictory, but it is clear from the ecological habits of the two fishes. Because the ayu is grown in a mountainous stream with a large flow, it often needs to consume a large amount of energy in the physiological metabolism to overcome the water flow to keep it from being washed away. Therefore, the sugars and fats obtained in the feed are used for energy metabolism. To save protein for growth. The dark silk, on the other hand, converts excess sugar into fat and stores it in muscle as a source of energy during wintering.
Proteins are the material basis of life. They are made up of more than 20 kinds of amino acids linked by peptide bonds. They are the way of life. The basic characteristic of life is the self-renewal of proteins. Its main function is the main components of the body's cells and tissues, such as meat, eggs, scales, lymph and blood, all of which are composed of proteins. The so-called growth can be seen as the accumulation of protein. Proteins can also form enzymes and hormones, which are involved in the regulation of metabolic processes in the body. All digestion, anti-analysis and synthesis reactions in the body require the participation and catalysis of various enzymes. As long as there is a lack of activity of a certain enzyme or enzyme, it can cause disease or even death. Hormones are regulators of fish's metabolism, growth, and reproduction. Proteins can also constitute various kinds of immunogenic antibodies, which are the main substances that resist pathogens and toxic substances. Proteins are also an important source of energy for fish. They can be quickly oxidized through dehydrogenation to generate energy, which is urgently needed for the life activities of fish. . Compared with livestock, fish is more likely to use protein as energy consumption first, so satisfying the protein demand of fish is the basis for the growth and development of fish.
The composition and proportions of proteins and fats in the bait formulation are primarily determined on the basis of detailed test data for each species of fish. Of course, when formulating the composition of the formula, it is based on the protein composition of the fish and the general ecological principles. For example, the crude protein content of carnivorous fish can be between 40 and 50%. The higher the culture temperature, the slightly higher the protein content, and the higher the culture water salinity, the slightly higher. The protein content of omnivorous fish can be relatively reduced, generally between 35-40%, depending on the fish species, some protein requirements are less than 30%, of which 30-40% of the protein can use plant protein sources Instead, the breeding effect is also very good.
Fat is an important source of energy and essential fatty acids for growth and development, and can promote the absorption of fat-soluble vitamins. Lipid defense is decomposed into a mixture of 2-monoglyceride and free fatty acid under the action of digestive enzymes. It is absorbed by fish and used to synthesize various cell components or decompose into energy. Fat is an important source of energy for various fishes, especially In the case of marine fish and cold-water fish with limited use of sugar, the energy of fat is very important. Therefore, the difference in demand for fats from fish is very different. The fat content of cold-water fishes can be as high as about 20%, and the demand for warm-water fishes can be 7-8%. However, the content of highly unsaturated fatty acids in cold-water fish should be higher than that of warm-water fish. However, the composition of the unsaturated fatty acids required for fish living in different ecological environments also differs. Generally speaking, the oceanic fish ε-3 series should be more, and the offshore fish ε-6 series more. There is no big impact either. However, the results of the tests showed that not only the appropriate fat content but also the appropriate ratio of eggs can be considered in the diet. If you do not consider the type of fat and feed protein and energy content, you can not give a more accurate content of fish feed fat. Therefore, fish can obtain the best growth effect when bait fat content is as high as 20%. However, if the fat content in bait is too high, it will also result in an imbalanced egg ratio and cause excessive accumulation of visceral and tissue fat, affecting yield and The quality of the fish has an adverse effect on the storage. Therefore, the fatty acid composition of the fat in the diet has a significant effect on the fat composition in the fish body and affects its growth.
Sugars show different nutritional values ​​for different fish species. Warm-water fish can use more bait sugar than cold-water fish and marine fish. The nutritional requirements of fish for sugars have not yet been determined. However, when carbohydrates are lacking in foods, other substances such as proteins and fats will be decomposed as energy and synthetic substances that have important biological functions, which are usually derived from sugars. Therefore, it is important to include appropriate sugars in the fish feed. The use of carbohydrates by fish seems to be related to the complexity of the sugar composition. Through experiments, seawater fish, such as lionfish and silk, can use dextrins and modified starches with contents higher than 25%, but Truesteel's use of glucose, dextrins and modified starches shows no difference. .
Third, energy and its demand energy is not a nutrient, it is released by the oxidation of protein, fat and sugar in the body. Absolute energy needs of fish can be determined by measuring oxygen consumption or heat production, but the energy in the feed must ensure that its effective energy can meet the needs of fish.
To grow and develop, fish must first survive, so energy intake is a basic physiological and nutritional requirement. Therefore, when designing fish bait formulas, the first consideration is the bait energy. However, due to the fact that protein bait prices are higher than other energy feeds, in fact feed protein content is often given priority. The protein and energy of the bait should be kept relatively balanced, and if the digestibility energy (DE) of the bait is insufficient or too high, the growth of the fish will be reduced. When the bait energy is insufficient relative to the protein content, the bait protein is not used for the growth of the fish, but is converted into energy to maintain the survival of the fish; conversely, if the energy in the bait is too high, the food intake of the fish will be reduced, thus reducing The optimal amount of protein required for fish growth and the intake of other important nutrients. Therefore, when the proportion of energy and nutrients in the food is too high, it will cause a large accumulation of body fat, affecting the food value of the fish. However, according to information, the demand for energy of sea fish is higher than that of freshwater fish.
Fourth, from the physiological and ecological requirements of minerals Unlike most terrestrial animals, fish not only from the feed intake of minerals (inorganic elements), but also from the external water environment. Calcium, magnesium, sodium, potassium, iron, zinc, copper, and selenium are usually absorbed from water to partially meet the nutritional needs of fish. Phosphorus and sulfur, however, are more effective in feed intake. Normal growth of fish requires inorganic elements. Its main functions include participation in bone formation, electron transport, acid-base balance adjustment, and osmotic pressure regulation. Minerals are also important components of hormones and enzymes and can activate enzymes c's complex biochemical metabolic mechanisms to control and regulate the intake of various inorganic components. Storage and excretion allow fish to live in a dynamically balanced water environment. The electrolytes Na+, K+, Mg+, Caz+, CI+, and HCO+ play an important role in osmotic pressure regulation and intracellular and extracellular ion regulation.
In the current formula for some seawater fish, the basis of the mineral part is mainly derived from the ancient lab's original formula for rats. Mixture or evolution of the channel forktail formula or some of the fish-binding formulas, followed by watching fish in saltwater fish. Butterfly fish and other formulas also evolved from the above. If you now breed fish such as real silk, Guo fish, teeth solution, black shao, and grouper, there will be changes in mineral demand. Let's take a look at a few examples.
1. Calcium is generally more calcium in the premix of freshwater fish because there is less calcium dissolved in the freshwater, and the dissolved calcium in the seawater tends to be saturated, so the supplementation of calcium in the marine fish is less. In fact, if too much calcium enters the human fish body and it exceeds the load of the kidney function, it will inhibit the growth. Therefore, when borrowing a freshwater fish premix formulation, appropriate adjustments should be made according to the salinity of the cultured seawater. High salinity Should be added less, low salinity should be added, but no matter how the water quality changes, calcium is essential for fish growth and development.
2. Phosphorus is basically a limiting factor in water. The amount of water available in the water environment is limited, so most of it needs to be obtained from the bait. The analysis results show that the phosphorus content in marine fish tissue is much higher than that of common terrestrial and freshwater fish. This physiological and biochemical difference must be brought to our attention. Obviously, more phosphorus should be added to the seawater premix, but too much phosphorus will affect the absorption of calcium. Therefore, the calcium and phosphorus demand and the calcium to phosphorus ratio of a certain cultured species have always been of concern. In addition, phosphorus in different species of marine fish metabolism and absorption are also different, such as oceanic fish lionfish, whales, etc., metabolic rate than the general demersal fish butterflies, cockroaches, groupers are much faster, so in the preparation In the case of dental premixes and grouper premixes, the phosphorus content is reduced compared to oceanic fish, otherwise it will affect the growth of the fish.
3. Iron From the point of view of the ecological environment of marine fish, the content of iron in seawater is not much, because it is alkaline. As for the content of fresh iron in the water, it depends on the specific water quality. Therefore, the amount of iron element added to a freshwater fish is not much affected, but the demand for saltwater fish should be met. Of course, the demand for different types of fish is also different. Excessive addition to the cost of fish increases metabolism, digestion and absorption. Obstacles, from a physiological point of view, oceanic marine fishes have a greater need for myoglobin content and are much higher than benthic fishes. Each myoglobin contains one iron atom, so iron is added in minerals. The quantity should be high. If such a formula is used to raise coastal fish, the amount of iron added should be reduced.
Many other kinds of elements, such as copper, zinc, aluminum, magnesium, potassium, sodium, iodine, selenium, etc., all have different physiological functions. If the amount is appropriate, it will promote growth, and vice versa, it will inhibit growth. Research work.
V. The demand for vitamins from the physiological ecology and the processing process Vitamins are organic compounds, unlike amino acids, carbohydrates and fats, and the vitamins need to be minimal. Animals take vitamins from outside (often baits) to maintain normal growth, reproduction and health. Vitamins are divided into water-soluble vitamins and fat-soluble vitamins. The demand for eight water-soluble vitamins is relatively small. It is mainly used as a coenzyme and is called B vitamins. The other three water-soluble vitamins, choline, inositol, and vitamin C, require a large amount and do not function as auxiliary enzymes but have other functions. Vitamins
D, E, and K are fat-soluble vitamins, and their function is not related to the enzyme, but in some cases, vitamin K has a role of a coenzyme. Lack of vitamins, mammals will appear to lack of curvature, but these deficiencies on the fish did not perform very well.
The research on the formula for the demand for vitamins in fish is extremely complicated. We know very little about it. In addition to the formulas required for the use and imitation of fish, there are many experimental studies on the demand for various vitamins in marine fish. However, it should be considered from the following two aspects.
1. Combining the Physiological Ecology of Fish Research The Demand for Various Vitamins Various kinds of fish have their own inherent physiological and ecological habits, so the demand for a certain kind of vitamins in the same environment will also be different. Oceanic fishes have the habit of migrating from oceans, which makes the life phenomena of energy production and consumption of aerobic exercise very strong. Therefore, the amount of coenzymes needed for energy supply, molecular synthesis and metabolism is large, then the demand for B vitamins The amount is more, and there are more vitamin A requirements for cytochromes in some electron transport chains, and some benthic fishes also need coenzymes to participate in the oxidation of anaerobic respiration metabolites and oxidative phosphorylation. Increased family, if you add less, will affect its normal growth. In 1984, Mr. Nakagawa of Japan made a test and placed Heisau in a closed water tank. No oxygen was supplied. With the drop of dissolved oxygen, 40 minutes later, he found a black side of the water on the side, and the feed contained algae. Only one-sixth of algae feed is not available. Mr. Mikonf also found a similar phenomenon in the ayu fish test. The aromafish that ingested the algae extract not only had a low side-ratio, but also had a high survival rate after returning to oxygenated water. This shows that the fish that feed on the algae extract increased The endurance to hypoxia, the reduction of pan-land hazards and the increase in the survival rate of live fish transport, algae extracts do not contain high levels of protein, fat, sugar and other nutrients, but are rich in trace elements and vitamins. Therefore, the fish have many good effects after eating algae. It is more realistic to study the demand for various vitamins in combination with the physiological ecology of fish.
2. From the processing point of view, when the demand for vitamins is combined with the physiological and ecological data obtained from the breeding experiment, the formula design must take into account whether the processing technology of the food has an effect on vitamins. Under normal circumstances, the production of marine fish bait is carried out under high temperature and high pressure, which will cause a lot of loss of many kinds of vitamins. As the shrimp bait undergoes granulation and conditioning, the vitamin loss is very large, but if it is lost during processing The parts added in advance to compensate for the loss will increase the cost of bait, otherwise it will not reach the appropriate proportion and demand for various vitamins. In order to achieve no loss of vitamins during processing, a granulation spray process was adopted in the processing of aquatic foods. This method is for fat-soluble vitamin A.
D, E, and K are good methods, but it is difficult for water-soluble B vitamins, especially vitamin C. However, there are still some methods, in recent years, vitamin C chemical treatment of many products, such as the envelope, capsule, poly-phosphorus vitamin C, etc., which reduces the loss of vitamins, increased the vitamin titers in the food.
Many diseases of marine fish in aquaculture are caused by the lack or imbalance of vitamins and minerals, which is different from the growth retardation caused by insufficient general nutrients such as protein, fat, and sugar. Growth is reversible and can be brought back when nutrition is good, but some of the injuries that the former form, such as bending of the spine, atrophy and deformation of the lid, often cause permanent disability. Therefore, it is very important to consider the loss of vitamins and how to remedy them during the development of feed formulations.
six. Forms and Species of Compound Feeds The current diet of saltwater fishes is categorized into five types:
1. Fresh and mixed powder; 2. Powder (bulk); 3. Expanded material (float); 4. Hydrated particles; 5. Hard particles, they have their own advantages and disadvantages. 1. Fresh or mixed powder This is the most primitive form of farming and feeding, but the effect is good. When a certain type of fish is not suitable for the start of feeding food bait, it is chopped separately with fresh material, or It is a good method to incorporate a part of the concentrated powder for feeding and let it slowly adapt to the food bait.
2. The powder (wet material) is actually the bait feed. This wet mass is also suitable when feeding trout. Because the shape of the country is slippery in the food group to drill and feed, but the bait loss rate is high. It also pollutes water quality. This form of bait has been replaced by pellets in intensive farming. The vast majority of marine fish are broad and flat in shape. They are mostly predatory animals that differ from squid. Therefore, they can be used when juvenile fish are bred. However, it is not appropriate for adult fish to feed this diet.
3. Expanded material (float) This feed is the ideal form for feeding saltwater fish. It can float on the water and can directly observe the situation of fish feeding. However, it also has its disadvantages, mainly due to the large investment in equipment. During the processing, there is a destructive effect on vitamins and some growth-promoting factors, which may produce some nutritional diseases. Therefore, if we must continue to develop, we should improve the process: whether to expand the raw material after the preparation of materials, or expansion granulation integrated, which should be comprehensively studied from the physiological metabolism of fish.
4. The hydrated granules are soft granules, and their moisture content is 20-30%, which can improve the digestion and absorption of the bait, and is a sinking property. This bait can add fresh bait to increase the lure, but due to the large amount of water, it is not suitable for mass production, and it can only be produced in small quantities or in current production. If the improved bait is resistant to storage and transportation, it is a promising seafood feed.
5. Hard pellets are the most commonly used aquatic grain pellets and have been used extensively in freshwater aquaculture with good results. However, it is rarely used in the cultivation of marine fish, because it does not have raw materials or hydrated diets. There are nutrients and attractants specific to some fresh foods, so the requirements for the integrity of their formulations are high. In particular, how to make marine fish eaten. Of course, the most promising feed is also this, the key lies in what material should be added to the premix in the formula. It is very difficult to introduce fish into the hook. This is the first thing that should be studied in hard pellet food formulations.
Now we briefly introduce the main species and major nutrient requirements of mariculture fish in China.
1. Sciaenops ocellatus (Sciaenops ocellatus), also known as redfish, is an excellent species of marine aquaculture introduced by the United States in recent years. It is a wide-temperature, wide-salinity, offshore warm-water fish. This fish has delicious taste, high medicinal value, fast growth, strong disease resistance, wide aquaculture feed, can be fed with bait, can produce soft and hard granules, crude protein requirement is 40-48%, fat content is
5-8% is appropriate, and it is an excellent species for mariculture in China.
2. Papemus major also known as Gage Red, Red Gage. It is the main breed of coastal farming in the north and south of China. It has wide temperature, wide salt, fast growth, strong disease resistance, and a wide range of diets. The demand for artificial forage protein is 40-52%, and the fat requirement is 10-15%. . In order to reduce the consumption of protein, the best fat content of 15% is appropriate, but not more than 20%, in order to prevent the abnormal body fat storage and fatty liver.
3. Sparus macroephalus (Sparus macroephalus) also known as sea bass, black Jiaji. It is also an excellent species for coastal farming in China. The variety has a wide diet and strong disease resistance and is suitable for high-density intensive cultivation. Its temperature range is 26-28°C, its suitable temperature range is 12-24°C, and its growth speed is fast. In general, it can reach 500g or more in 2 years. . The amount of protein required for artificial diets is 37-42°C, and 10-12% for fat.
4. Catfish (Lateolabrax japonicus) also known as the guard board. Is a ferocious fish, it is widely food, fast growth. The ability to adapt to the natural environment is strong and salty, and it can live in 2.0-32.0% of the water. The market is vast and the economic value is high. Individuals with 2 years of age can grow to more than 1 gram. The temperature range is 2-32°C, and the suitable temperature is 8-25°C. It is an ideal object for cages and earth ponds in the north and south, and the artificially-combined dietary protein requirement is 45-50%. Above adult fish. The suitable range of fat is 13-18%. Because fresh fish use vinegar as their energy source, their ability to use fat is very high because high fat is an important nutrient for whales.
5. Fugu rubripes, also known as the river, enjoys the reputation of "King of Fish" because of its delicious flavour. The benefits of export exchange are very good, and it is a popular breeding breed for mariculture in northern China in recent years. Because of the many problems in the ecological research of the Red Fins, it is not clear. The research and development of artificial compound feed is difficult. However, due to the good breeding efficiency, it also promoted the research of compound feed. After testing, the requirement for protein is 45-50%, while the feed containing 55-70% protein has a stable weight gain without much change, whereas the fish body containing 75-80% protein feed has a slight decrease in weight gain. The protein requirement is 45-50%, and the fat content is 6-8%. If the content is increased to 10%, the weight gain of the fish will decrease.
6. Pdicthys oliveaeus is also known as flatmouth fish. flounder. Yasu is a valuable economic fish for marine aquaculture. In Japan, artificial breeding tests were conducted at the end of the 19th century. As the main object of the increase and culture fishery, the history is not long, but it has come to an end in the research and development of artificial breeding and breeding. The world leader. In China, dental freshwater has been listed as one of the targets for marine fish breeding, and artificial breeding has been basically successful. Research on nutrition has only begun. Now we can see how the teeth feed off. Like to swallow the food, the minced bait is not suitable, so that the use of compound feed aquaculture, nutritious needs, protein is 48-56%, because the fresh meat contains less fat, so the fat requirement is not high, generally 6.0 A 8.0% is appropriate.
7. Epinephelus spp is also known as piebald and grouper. Belongs to the family Lipidaceae. About 100 species are distributed in the Red Sea, Indian Ocean, and western Pacific Ocean. China is produced in the South China Sea and East China Sea. It is a carnivorous and benthic fish that grows faster, has larger individuals, is rich in nutrients, and is delicious. People love it and it is an excellent species for marine aquaculture. In recent years, China has also conducted research on artificial propagation and cage culture techniques. In order to reduce costs, increase economic efficiency, and ensure adequate feed supply, its nutritional needs have also been studied and achieved good results. Grouper feeding artificially-combined bait test proved that the bait contains 40-50% of the protein, its feed efficiency, protein conversion and utilization are higher, when the bait protein content is lower than 40% or higher than 50% At the time, the growth of the grouper decreased, and the artificial diet containing 40% protein to support grouper was considered the most economical. The fat requirement is 6-10%.
In the external morphology of the above fish artificial diets, they began to be tested as hydrated wet pellets, tested and domesticated, and then gradually transformed from warm pellets into hard pellets. Now there are tooth solutions and groupers. For the fish's commodity bait, there will soon be more varieties and series of marine fish artificial diets available to farmers.
Plastic Net,Plastic Netting for Garden,Plastic Trellis Net,Plastic Net Fencing
COFCO HEBEI INTERNATIONAL TRADING CO., LTD. , https://www.cofcohb.com