Factors affecting feed safety

Safe feed refers to the feed of food animals. The various ingredients do not produce organic and inorganic substances that are harmful to human health in the animal body (Liu et al., 2000). The production of safe feed is an important issue related to the sustainable development of feed production and human health. The main factors affecting feed safety are the quality of feed ingredients, the safe storage of feed ingredients, the control of the amount of various additives in the formula, the control of artificial addition during processing, the rational design of feed processing technology and the proper selection of parameters, and the operation process. Manage feed storage management after processing. Safe feed can only be produced if all aspects of the processing process are strictly controlled.

l Control and safe storage of raw materials

Feed ingredients are the first control point for the production of safe feed. Some plant feed ingredients are used in large quantities during the growth process due to pests and diseases, resulting in pesticide residues in cereal products exceeding the standard. Feed mills should be strengthened when receiving raw materials. Detection of pesticide residues. In addition, the waste water and waste gas discharged from industrial production are also seriously polluted by feed ingredients.

At present, due to the limitations of testing equipment, most feed manufacturers have not tested pesticide residues and industrial contaminated raw materials. This is a major hidden danger in the production of safe feed, and feed producers should pay sufficient attention. The moisture of feed ingredients is the key to safe storage. Especially for some freshly harvested plant materials, the water generally does not reach the standard of safe storage. During storage, the raw materials are highly susceptible to mold pollution and produce a large amount of mycotoxins, so that the quality of feed produced. deterioration. Therefore, it is necessary to improve the storage conditions of raw materials and control the moisture of feed ingredients (safety moisture below 12%) to minimize mold pollution, which is the most effective and positive method. Many raw materials are not economically operative to achieve a fairly dry level. The use of anti-fungal agents to control mold growth is an effective measure. However, the anti-fungal agent cannot remove the mycotoxin from the raw materials, so mold control measures must be taken as early as possible before mold contamination occurs.

At present, due to the shortage of feed ingredients, the adulteration of raw materials is very serious, and the adulteration of feed ingredients brings trouble to the production of safe feed. Therefore, when receiving raw materials, it is necessary to pass a rigorous test to confirm whether it meets the quality standards, and resolutely prevent unqualified raw materials from entering the factory.

Most of the raw materials in the feed are corn, which are usually stored in vertical silos, especially steel silos. Due to the large difference in temperature between day and night, it is easy to cause evaporation of water in storage materials and condensation of water vapor, so that some raw materials close to the silo wall are The water content is too high, such as long-term storage, it is easy to cause mildew in the raw materials. Therefore, the management of raw materials in the silo should be strengthened, and the moisture of the raw materials can be reduced by means of overturning to ensure the safety of the stored raw materials.

2 cleaning of raw materials

In feed processing, people often pay attention to the cleaning of large impurities and magnetic impurities in feed ingredients to ensure the safety of feed processing equipment, and the cleaning of small and medium impurities in feed is often ignored. These small impurities are complex and are a breeding ground for various harmful microorganisms. When the moisture and temperature of the raw materials are suitable for their growth, the nutrients of the raw materials are the medium, which causes rapid growth to produce a large amount of harmful substances, posing a threat to feed safety. Therefore, small impurities should be removed in feed production to facilitate the safety of the feed and ensure product quality.

3 control of harmful components in raw materials

The raw materials used in feed processing are very complicated. Some raw materials have natural toxic and harmful substances, such as alkaloids, free gossypol, tannins and protease inhibitors in vegetable raw materials. Phytic acid and toxic nitro compounds, such as histamine, anti-sulfamin, etc. in animal raw materials, and blood, fat, bone meal or meat and bone meal of mammals contaminated with microorganisms, such toxic and harmful substances cause various kinds of animals. harm. Therefore, when selecting raw materials, such raw materials should be controlled according to actual needs. For example, cotton and rapeseed cakes should be selected from detoxified cakes or controlled dosage, and meat and bone meal is prohibited in ruminant animal feed.

4 control of various additives in the formula

In addition to meeting the production performance requirements of livestock and poultry, the feed ingredients should meet the national health standards. At the same time, the national regulations on feed should be implemented. It is strictly forbidden to use illegal drugs and antibiotics. For feeds that require the addition of drugs, drugs approved by the state should be added, and must meet the applicable animal range, dosage, withdrawal period and precautions. In order to save the cost of feed production and make full use of feed resources, some unconventional feed ingredients have been applied. When using these raw materials, first of all, to ensure their own safety, for the raw materials with certain toxicity, take measures to prevent them.

With the development of biotechnology, the proportion of GM crops and their by-products used as feed is gradually increasing. Raw materials such as high oil corn, high lysine corn, low toxic rapeseed cake, and high methionine soybean have been used in feed production. . However, the use of these genetically modified plants as feed ingredients has not yet reached a consistent affirmative conclusion on the safety of animal health and animal products. Therefore, it is necessary to be cautious when choosing GM products for use as feed ingredients.

5 manual addition control

In the design of the feed factory, in order to facilitate the addition of some small materials, reduce the number of feed silos, and save investment costs, it is often designed to manually add ports, which is reasonable in process design. However, manual additions may pose a threat to safe feed production. In order to ensure the accuracy of manual addition, sound control technology and photoelectric combination method can be used in the process design to control the addition of additives. This technology prevents additive additions or repeated additions, and should be enhanced to prevent manual metering errors.

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6 feed processing technology design and equipment selection

Feed production is a combination of processing equipment and conveying equipment. Reasonable design and selection of equipment is also an important part of safe feed production. Mainly to reduce the material classification and residue in the process, while using heat treatment during processing to eliminate the effects of anti-nutritional factors and harmful microorganisms in the raw materials.

6. l Classification of processing

In feed processing, the difference in density of the feed components, the difference in the particle size of the carrier, and the incorporation of minor components such as additives with other components in the feed are insufficient, which is an important cause of grading. Processes such as conveying, charging and unloading of raw materials can also cause grading, and improper design of manual operations and processing processes can also cause grading. The measures to reduce the classification are to rationally design the feed processing process and select high-quality and precise equipment; to ensure the uniform mixing of the raw materials by adjusting the composition of the raw materials and the particle size of the crushing; to effectively carry the micro-components to change the mixing of the minor components. Characteristics; adding liquid components to increase the adhesion of the powder; granulating or expanding the product also helps to avoid the above phenomenon. For powdered products (especially composite premixes), the finished powdered material after mixing should minimize the transport distance to reduce the impact of material grading.

6.2 Residual contamination during processing

Many factors can cause residual contamination of the feed in the equipment leading to cross-contamination. If appropriate measures are taken in process design and equipment selection, residue generation can be reduced. In the process design, the conveying process uses the form of the distributor and the self-flow as much as possible, and the horizontal conveying is less used. For horizontal conveying equipment, such as screw conveyors and scraper conveyors, there are more or less residuals due to structural reasons. The equipment should be designed to be easy to enter and easy to clean, or to use a self-cleaning scraper conveyor. Under the conditions that meet the process requirements, minimize the number of material lifts and the number of buffers. The suction and dust removal system should be equipped with an independent wind network as much as possible, and the collected dust should be directly sent back to the original place to avoid secondary pollution. In particular, the production of the compound premix for dosing should be handled in this way. The metering of minor components should be arranged as far as possible in the upper part of the mixer. If it has to be lifted or transported after metering and weighing, high-density pneumatic conveying must be used to prevent classification and residue. High-risk trace components such as drugs must be added directly to the mixer. For the production of medicated feeds, special production lines should be used as much as possible to minimize the risk of cross-contamination. In order to reduce the impact of residues on the feed, some cleaning devices can be designed to clean up special parts of certain equipment with compressed air. In the selection of equipment, the accuracy of the electronic type and mixing equipment of the measuring equipment should be determined. The measuring equipment and the electronic scale should be determined according to the nature of the different proportioning materials in the range selection. The metering equipment with the same scale is used to meet the measurement of different materials. Requirements. In the production of compound feed and composite premix, the choice of mixer is important. The mixer should be able to achieve a mixing accuracy of not more than 5% with a coefficient of variation of one hundred thousandth. The mixer should be designed to ensure that only as little material remains in the mixer after each batch of material has been mixed. Due to different particle size and different final product requirements, in the production of premixed feed, the particle size of the material is small, the mixing uniformity is high, the required residue is small, and the material has static electricity during the mixing process. The characteristics of the mixture are different for the mixer. Buckets, buckets, batching and buffering hoppers also produce residues. When selecting equipment, the inner surfaces of the slides, silos and hoppers should be smooth and free of dead spots. Unreasonable liquid addition methods will also affect the residue of materials, so pay attention to

6.3 Application of heat treatment process

The effect of tempering heat treatment prior to conventional granulation depends on temperature, time, and the quality of the steam. The role of quenching and tempering is to improve the quality of pellet feed, improve feed digestibility, and at the same time destroy the anti-nutritional factors in the raw materials, kill harmful microorganisms in the raw materials, and control the sanitary quality of the pellet feed. This quenching and tempering treatment is limited by the structure of the pellet machine, and the conditioning effect is not satisfactory. At present, the improvement in quenching and tempering treatment is mainly to increase the quenching and tempering distance to prolong the quenching and tempering time, so that the hygienic quality of the feed after quenching and tempering is improved. Another method is to use the expansion or extrusion method to make full use of time and temperature, combined with mechanical shearing and pressure, the treatment intensity is high, and the sterilization effect is more obvious. Expansion or extrusion puffing and tempering make the sanitary quality of the feed better.

6.4 Problems with external spraying applications

The heat sensitive substance may cause loss during the heat treatment process, so it may not be added during the quenching and tempering process, and may be added by external spraying. These substances are added to the surface of the particles, which may cause particle pulverization during transportation or transportation, and the surface coating material may be pulverized to produce an enrichment effect and evenly distributed. Therefore, the outer coating of the particles should make the outer coating material and the particles tightly combined, and the processing quality of the particles is the guarantee of the quality of the outer coating. Generally, the effect of the outer coating of the extruded product is ideal.

7 management of the production process

Feed production is more complicated. There are many feeding points for raw materials, many production equipments, many forms of conveying equipment, and many suction and dust removal pipelines. Therefore, the management of production process is a systematic project, which plays an important role in the production of safe feed and the quality of control products. .

7. l Raw material receiving and storage management

When receiving and storing raw materials, it is necessary to ensure that the quality of the raw materials entering the factory meets the standards. The raw materials should be stored in the corresponding positions according to different varieties and quality to prevent cross-contamination. Storage raw materials should be first-in, first-out, minimize quality changes, prevent external environmental factors from affecting raw materials, and prevent pests, rodents and microbial growth from harming raw materials.

7.2 Feeding and conveying equipment management

When feeding, check whether the quality of raw materials has changed. When it is found that the raw materials are abnormal, take corresponding measures. The specifications of the raw materials to be invested shall be in accordance with the formulation requirements, and the various raw materials shall be put into the corresponding silos according to the regulations. Manual feeding is a highly responsible position. To ensure the accuracy of measurement and feeding, it is necessary to establish a system of mis-investment and mis-investment reporting. Bucket elevator bottom, scraper conveyor, screw conveyor and slide pipe buffer section are prone to residual, and should be cleaned regularly; bucket elevator unloading, dilute phase pneumatic conveying, and slip pipe will classify materials according to material properties. Determine the discharge mode of the bucket elevator, reasonably set the buffer section of the slide pipe, and the material after mixing is strictly prohibited to use pneumatic conveying to prevent the occurrence of classification.

7.3 Production Equipment Management

It should be checked whether the equipment is running normally, whether there is any leakage of material, and it is necessary to prevent the leakage of equipment oil to the material. The pulverizer should use the corresponding sieve plate to control the pulverization particle size, and pay attention to whether the sieve plate is damaged or not. The weighing accuracy of the measuring equipment is very important. It is necessary to use different measuring instruments to meet the weighing of the materials. If the amount of small-sized materials does not meet the measurement accuracy requirements, the small-sized materials must be diluted. To ensure the mixing time of the mixer, the mixing uniformity must match the process requirements. Premixes should be packaged directly to prevent shipping grading. To ensure the quality of steam during the quenching and tempering process, it is necessary to make full use of the moisture, temperature and time factors to make the potential of quenching and tempering. The quality of the particles should meet the requirements of the subsequent process. Particle cooling determines the cooling time based on formulation requirements, particle size and environmental changes. Speed ​​and cooling air flow, so that the moisture and temperature of the particles meet the storage standards. When the particles are coated, the amount of spray should be flexibly adjusted according to the flow rate of the particles to ensure the amount of spray applied and uniform spray. When packaging, it is necessary to ensure accurate measurement of packaged materials, and at the same time strengthen label management to prevent mislabeling.

7.4 Dust removal system and cleaning

Dust removal and cleaning in the feed production process are important measures to ensure sanitary production. Each feeding point and equipment that is easy to generate dust should be provided with suction ports. The dust removal system should be set according to the material characteristics. It is best to set up an independent suction system. Dust can be directly returned to the production equipment for secondary production. The production workshop and production equipment should be cleaned in time to prevent dust accumulation. The cleaned materials should be treated according to the regulations to prevent secondary pollution.

8. Post-processing feed storage management

The processed materials are stored according to the regulations to prevent the feed from deteriorating during the storage process, which is beneficial to the first-in-first-out of the finished products, and does not cause pollution during transportation. It is strictly forbidden to mix feed with pesticides, fertilizers and other chemical products. When the user stacks the finished product, the feed should be prevented from being contaminated in the livestock house. The user should be instructed to use it properly. The medicated feed should pay attention to the withdrawal period of the product to avoid the residue of the drug in the animal product. The feed recovered from the user should be treated according to different properties and recorded accordingly.