Production of fish feed

1, rational design of feed formulations

Before designing the formula, the species and stage of growth of the cultured fish must be clarified to determine the level of nutrients such as protein and energy in the feed. It is necessary to meet the needs of the fish for growth and to make the ratio of energy and protein moderate. High and low energy and protein ratios are not conducive to fish growth. When formulating formulas, we must also consider the relationship between feed nutrient water and bulk density. We must ensure that fish can consume sufficient nutrients and make them feel full. Fish mainly use protein as an energy source for fats and sugars. The utilization rate is lower, so the demand for protein from fish is higher than that of livestock; in general, the price of protein feed is higher than the ratio of energy feed and crude, and the ratio of protein feed is reduced. This will increase the feed virtually. Cost; Different stages of fish growth require different nutrients such as 43% - 41% of the protein content of carp juvenile fish, 37% - 42% of fish species, and 28% - 32% of adult fish .

2, the choice of feed ingredients

The selection of raw materials should be based on the principles of high quality and low price, stable supply and convenient transportation. If the conditions permit, the more types of raw materials are, the better, so that the necessary amino acids in the feed can be balanced as much as possible to satisfy the needs of fish for various essential amino acids, and moldy and deteriorating raw materials must not be used. Mildew raw materials contain a large number of germs and toxins, such as moldy corn contains highly toxic aflatoxins. These feeds can easily cause diseases in fish; cottonseed cakes and rapeseed cakes are cheap and have high protein content, but because they contain anti-nutritional factors such as gossypol and glucosinolates, More use will affect the growth of fish, so to limit the amount, generally not more than 10%. Many farmers like to use cheap oil dregs and patties, but this kind of original species contains a large amount of animal skins, which affects the smooth progress of crushing and granulating process. The fish is also not easily digested after eating; the oil dregs and patties The fats contained are saturated fats, and some have already begun to rancid due to long storage time. Fishes have low saturation fat and low utilization rate. Excessive intake of rancid fat also causes fish to suffer from fatty liver and other diseases. When raw materials are used, the moisture content of the raw materials should also be taken into consideration. The moisture content of air-dried feed in the southern region is generally 12% to 13%. Excessive water content will reduce the nutritional value of the feed, and may also lead to moldy feed and shorten the storage time of the feed.

3, the control of processing technology

The process flow for the production of self-produced feed in rural areas generally includes smashing, mixing and granulating, and where conditions permit, it also includes conditioning before pelleting. Crushing can increase the contact area between feed and animal digestive enzymes, improve the digestion and absorption of substances, nitrogen and energy, and reduce the feed coefficient. The coarse and fine crushed particles are not good. Generally, the raw material for compound feeds for fish should be crushed until they pass through a 40-mesh sieve. The size of the top material on a 60-mesh sieve is not more than 20%. The optimum grinding degree of the carp fingerlings feed is 1.77mm, and the crucian carp juvenile feed must have a grinding degree of 50-60 mesh (0.30-0.25mm).

Mixing is the main link to ensure the quality of feed and improve feed efficiency. Feeding practice shows that if the ingredients in the compound feed mix unevenly, it will significantly affect the growth of fish, and severe cases will lead to death. This is because the uneven mixing results in uneven distribution of various nutrients in the same batch of feed and can not achieve the effect of the formula. The excessive local concentration of certain additives such as heavy metals will cause fish poisoning to die. The quality of mixing can be improved from the following three aspects.

1 Suitable loading. Too much or too little charge will affect the mixing quality. The batch mixer's fullness factor should be 0.6-0.8. The continuous mixer's fullness factor should be controlled below 0.5.

2 master the mixing time. If the mixing time is too short, sufficient mixing cannot be achieved. If the mixing time is too long, separation will occur, which also affects the mixing quality. The mixing time is determined by the mixing speed of the mixer and is typically around 6 minutes.

3 Operation sequence. Generally, the components with large proportions are added first or most of the components are put into the machine and then the small and minor components are placed on the material; the materials with large particle size are added first, and the particles with small size are added; the materials with small specific gravity are added first. , after the major increase.

The quenching and tempering is that the feed is steamed before granulation, and the feed and steam are stirred and mixed. Under the action of moist heat, the starch of the feed is gelatinized, the digestibility can be improved, and the feed is formed after conditioning. The key to quenching and tempering is the control of quenched and tempered steam. It is required to be used in saturated steam. Generally, the tempering temperature is determined according to the composition of the material. Because of the high content of natural protein in fish feed, the feed temperature needs to reach 85° C. or higher.

By making the feed pellets, various nutrients can be fixed in the pellets to keep animals from picky. Fish feed pellets can also reduce waste, reduce water pollution, and reduce morbidity. The particle size of the pellet feed should be determined by the width of the fish's crack, and the particle size of the feed should be less than 1/2 of the split: the total length of the grass species and the corresponding feed should be 4.0-5.0cm, 0.8-1.0. Mm; 5.0-6.0 cm, 1.2-1.5 mm; 6.0-7.0 cm, 1.5-2.0 mm; 7.0-8.0 cm, 2.0-2.5 mm.

4, the rational use of additives

Feed additive is a general term for substances that can protect the digestive absorption of nutrients in feed, regulate body metabolism, improve animal health, improve the use efficiency of nutrients, and improve animal production levels to improve the quality of animal products. For vitamins and mineral additives, due to the variety and quantity, and the high technical content of various vitamins and minerals, the effect of vitamins and single minerals purchased by farmers is very good. Poor, can not achieve the balance between various types of substances. When producing self-mixed feeds, vitamins and mineral premixes produced by specialized manufacturers can be selected and added reasonably according to the species and growth stage of farmed fish; the production of self-made feed can also be formulated according to own needs to make a small amount of special feed, such as according to self The incidence of fish in the pond can be made by adding the symptomatic medicine to the feed to make it easy to use. In the use of drug additives must comply with the relevant national laws and regulations, absolutely not allowed to add drugs that are prohibited by the state. Some farmers have added banned olaquindox to the feed to increase the growth of fish. However, a large number of studies have shown that although olaquindox can antibacterial promote growth, long-term use will reduce the fish's resistance to transport performance, increase the mortality rate of transport, but also will reduce the quality of fish products and endanger human health.

Recent studies have shown that the addition of new additives such as probiotics, enzyme preparations, and Chinese herbal medicines to feeds can significantly improve fish nutrition, promote fish growth, and reduce the incidence rate. Probiotics is a concept that is related to antibiotics. It refers to active microorganisms or their cultures that can be directly fed to animals and regulate the animal's gastrointestinal microecological balance to prevent diseases, promote animal growth, and improve feed utilization; probiotics can To a large extent replace the function of antibiotics without any toxic side effects. Enzyme is a biologically active protein. As a feed additive, it is mainly a digestive hydrolase, which includes proteases, amylases, plant enzymes, and cellulases, as well as complex enzyme preparations containing various enzymes. The combination of probiotics and enzyme preparations in production has a better effect. The optimum combination of grass carp feeds is 0.52%-0.66% of probiotics and 0.20%-0.21% of enzyme preparations; the optimum level of probiotics in carp feed is 0.57%. -0.69%, 0.14%-0.18% of enzyme preparation added. Chinese herbal medicines are abundant in resources. Over a long period of time, our people have accumulated rich experience in using Chinese herbal medicines to prevent and cure diseases. Chinese herbal medicines are used to make baits in feeds, which are easy to use and non-toxic and non-residual. For example, adding three yellow powders to feed can effectively prevent grass carp three diseases. , Pine needles, leaves, alfalfa and other Chinese herbal medicines can increase the survival rate and promote the growth of fish feed. With the in-depth development of the pollution-free food operation in China, the pollution-free fish feed is inevitably required. Therefore, these new additives should be used as far as possible when producing feed for fish.

Common medical masks are used to block spouts exhaled from the oral cavity and nasal cavity, and can be used for one-time hygiene care in ordinary medical environments with the lowest protection level. It is suitable for general hygiene care activities, such as sanitary cleaning, liquid distribution, cleaning bed units, etc., or the blocking or protection of particles other than pathogenic microorganisms such as pollen.
Conforms to the relevant registered product standard (YZB), generally lacks the filtration efficiency requirements for particles and bacteria, or the filtration efficiency requirements for particles and bacteria are lower than medical surgical masks and medical protective masks, only reaching 20.0% for 0.3μm diameter aerosols -25.0% protection effect, can not reach the filtration efficiency of particles and bacteria, can not effectively prevent pathogens from invading through the respiratory tract, can not be used for clinical invasive operations, nor can it protect particles and bacteria and viruses, only limited to dust particles Or aerosol plays a certain mechanical barrier.

Common Medical Mask

Medical Face Mask,Disposable Medical Mask,Disposable Protective Face Mask,Non Woven Surgical Face Mask

Guangzhou Aikangli Medical Technology Co., Ltd. , https://www.aikanli.com