Technical points of production and use of premixed feed

Premixed feed is a uniform mixture of multiple additives of the same class or different types of multiple additives formulated in a certain proportion. Although the proportion of premixed feed is very small in the full value feed, it plays an extremely important role in the feeding effect of the full value feed. Scientific premix feed formulation is the key to premix production.

To produce high-quality premix, not only need scientific formula, but also need high-quality raw materials, fine equipment technology and a set of perfect management measures. Premix is not a simple commodity, but a technology with high technical content, which is a comprehensive embodiment of raw material quality testing, nutrition formula design, livestock and poultry feeding management and other technologies. In order to further promote and popularize premixed feed technology, the production technology and application of premixed feed are briefly introduced in this paper.

1 Production purpose, characteristics and functions of premixed feed

The purpose of the production of premix is to dilute and expand the trace component additives, and the effective components of which are evenly dispersed in the compound feed. Premix can be produced by manufacturers specializing in the production of such products, or can be produced in a special production workshop attached to the feed mill.

Premix has the following characteristics:

① Complex composition. Premixes with good quality generally include 6 or 7 kinds of trace elements, more than 15 kinds of vitamins, 2 kinds of amino acids, 1 to 2 kinds of drugs and other additives (antioxidants and mildew agents, etc.), and the properties and effects of various feed additives are different, and the compatibility relationship is complex; ② Small dosage, large effect. Generally, the proportion of premix in compound feed is 0.5%~5%, although the amount is small, it has a great effect on the improvement of animal production performance, the improvement of feed conversion rate and the preservation of feed. ③ Can not be fed directly. The active ingredient concentration of additives in premix is very high, which is generally tens to hundreds of times the amount required by animals, and it is easy to cause animal poisoning if fed directly.

There are four main functions of premix:

① The trace components of the additives can be evenly distributed in the compound feed; ② The unsatisfactory characteristics of trace components, such as instability, water absorption, electrostatic adsorption, etc. are compensated and improved by the pre-mixing process; (3) Standardize the level of additives; ④ Simplify the production process of general feed processing plants and reduce investment.

2 Main technical points of premixed feed production

2.1 Adopting advanced formulations -

Premix feed formula is the core of production technology, is a special premix manufacturers of animal nutrition experts according to the nutritional needs of animal growth and production stages, according to the basic nutritional content of domestic feed raw materials, to the lack of what supplement what, economic and reasonable, low value and high efficiency as the principle, while considering the external environment and processing technology and many other influencing factors, carefully designed. On the one hand, combining the nutritional needs, the user's feeding level and conditions to select the appropriate amount of additive raw materials; On the other hand, to consider the needs of processing, for most of the components that do not affect safety, such as nutritional additives, grasp the appropriate amount is the key to formulation technology.

The dosage and usage of pharmaceutical feed additives and some sensitive ingredients (such as selenium, copper, etc.) must have sufficient scientific basis and necessary practical experience, otherwise, it is easy to make mistakes and serious consequences. The ratio of raw materials is an important factor affecting the quality of premix products. The proportion of active ingredients and diluent, the proportion of various trace elements and the proportion of relevant active ingredients in premix should be just right. The formula should not be static, it should constantly adjust the formula according to market feedback, local conditions, seasonal changes, the latest technology and product information, so as to be rigorous but flexible, and always make premix products close to the national conditions and production reality.

2.2 Selection of high-quality raw materials

The quality of raw materials has A great impact on the actual utility of premix, the most basic requirements of high-quality raw materials are high purity, no toxic and harmful substances, the most important of which is the active ingredient content, especially the easily destroyed vitamin A and vitamin C and other additives, should be determined by the actual amount.

The raw materials of trace element compounds must have the characteristics of high biological potency, stable physical properties and less toxic and harmful substances. In addition, some additives, its own quality and dosage form are easy to affect other additives, and special attention should be paid to them. For example, ferrous sulfate heptahydrate has A strong hygeability and is very destructive to vitamin A, while ferrous sulfate monohydrate has a smaller impact on vitamin A, and if a protective agent is added, the impact is smaller and the activity itself is very good.

The manufacturer of premix should choose high-quality raw materials, and the quality and titer of raw materials should be accurately determined. When choosing vitamins, you should pay attention to the following two points:

① Select the one with high biological value;

② Choose different vitamins according to climate characteristics, such as thiamine mononitrate is better than thiamine hydrochloride in hot and humid summer. In the selection of trace element raw materials, we should consider many factors such as the content of its components, particle size, crystal water and the content of toxic and harmful substances. Drug feed additives, but also pay attention to safety issues, be sure to use according to the instructions and test materials provided by the manufacturer, etc., to fully understand its use period, withdrawal period and precautions.

2.3 Use the best carrier and diluent

The carrier is the particle that carries or adsorbs the trace active ingredient, it is the inactive substance in the premix. The selection of the carrier should follow the following principles: strong chemical stability, do not damage the adsorption; Moderate grain size, good mixing with full price feed; The price is low. The particle size of the carrier should be between 0.177 and 0.59mm. The density should be similar to the density of trace components carried, and the carrier density in the composite premix should be the average density of each trace component. When mixing the carrier and additive, adding 1.5% vegetable oil can improve the adhesion of the carrier; The water content of the carrier should be controlled at 8%~10%, and the carrier should not damage the activity of the active ingredients. The pH of the carrier is close to neutral.

Commonly used carriers are: shell powder, wheat bran, corn, bran powder, degreased rice bran, stone powder, zeolite powder, salt and so on. Diluent is a component that reduces the concentration of active substances in the premix and separates the trace particles from each other. It is an inactive substance like the carrier, which plays a role in reducing the reaction between active ingredients and is conducive to the stability of active ingredients. The requirements for diluent are: the water content of diluent should be less than 10%, no moisture absorption, no caking; The particle size should be between 0.05 and 0.6mm; The surface should be smooth and have good fluidity; The pH value should be between 5.5 and 7.5, without static charge; It must be edible, harmless and stable for animals.

2.4 Raw material pretreatment

Vitamin is susceptible to oxygen, moisture, heat, light, metal ions and other factors to reduce its activity. In order to meet the requirements of the production process, all vitamin additives must undergo special pretreatment to maintain their stability and activity. Emulsification technology can be used to form particles, uniformly dispersed in the matrix, and then coated technology is used to form particles covered by gelatin to make microcapsules.

The particles treated in this way can resist mechanical operation, have good oxidation resistance and good mixing performance. Trace element additives mainly refer to mineral salts and oxides of copper, iron, manganese, zinc, etc. Some of these compounds are poor in water solubility, and some are easy to absorb moisture, etc., and must be properly pre-treated before application to change some of their physical properties, so that it can meet the processing requirements and ensure product quality. The pretreatment technology mainly includes drying treatment, adding anti-caking agent, coating, fine granulation, pre-grinding, etc.

2.5 Use high-precision production equipment

Scientific formula to rely on accurate measurement of ingredients to achieve, to ensure that in strict accordance with the formula requirements of accurate ingredients, it is necessary to have advanced measuring equipment and reasonable process, premix production of all kinds of metering equipment accuracy, stability are very high requirements, therefore, the relevant equipment to strengthen management, regular calibration. For the addition of small amounts of drugs that will affect safety, such as selenium, high copper and other additives, special care should be taken in the measurement and dilution.

The mixer is the most important equipment for the production of premix, and different premix varieties need to choose different mixer equipment, such as non-gravity particle machine, conical mixer, double helix ring belt mixer, double shaft pulp blade mixer and fast no residue mixer. Under normal circumstances, the requirements for the mixer are: (1) high mixing efficiency, the best mixing time is short; ② High mixing uniformity; ③ Reasonable structure, low residual and easy to be removed; ④ convenient loading and discharging; ⑤ Good sealing performance, less leakage; ⑥ Prevent static electricity.

2.6 Mixing Evenly

Although feed mixing is only a physical process, due to the obvious differences in raw material density and other characteristics, it is necessary to scientifically select the equipment, mixing time and the appropriate carrier or diluent, the process flow is as simple as possible, and strive to mix evenly. High-quality premix, all its components should be evenly distributed, any sample taken for testing, its proportion between multiple components should be consistent with the formula. However, due to the influence of various factors, there will be differences between different sampling rooms and different batches.

Poor uniformity of premix means that the actual intake of animals and the formula of the supply does not meet, which directly affects the effect of adding and feeding feed, especially for some safe dose and toxic dose of trace ingredients, poor uniformity may cause unsafe consequences, so uniformity is an important quality indicator of premix. The index of uniformity is mixed uniformity, which is expressed by the coefficient of variation, and the coefficient of variation should be less than 7%.

2.7 Introduction of HACCP management system

In today's meat food safety more and more attention, the introduction of HACCP management system in premix production is very necessary. First of all, we should analyze the harmful factors that may occur in the process of feed production and processing, determine the critical control points, and formulate control standards, and then implement feasible and effective control measures, establish testing methods and procedures, timely find out whether there is deviation between the control measures and the set standards, take effective corrective measures, and adjust the production and processing and control methods in a timely manner. And the HACCP system should be fully verified. The implementation of HACCP can improve the quality control awareness and quality control level of premix production enterprises, and will promote the overall improvement of premix production level.

3 Problems to be noted in production

3.1 Feeding standards as the main basis

Feeding standards are the nutritional requirements of animals under different feeding purposes, which can be used as the basis for making premix formulas, and in specific applications, it also depends on the extensive knowledge of animal nutrition.

(1) The nutritional requirements on the feeding standard should be the sum of the same nutrients provided by various components, rather than the amount to be added; ② It is best to use premix raw materials after direct determination of composition, and the synergistic and antagonistic effects between various nutrients should be considered; (3) The nutritional requirements in the feeding standard are only the minimum requirements required by the animals, and the appropriate amount should be added according to the actual conditions when making the formula to ensure the real needs of the animals for a nutrient under different conditions.

3.2 Consider the process and processing losses

In the process of premix processing, first of all, it should ensure that the accurate feeding is strictly in accordance with the formula requirements; Secondly, different adding methods should be adopted according to the characteristics of various components. Finally, ensure that the mixture is uniform (CV less than 7%). In the process of feed processing (such as crushing, granulation, etc.), some nutrients such as vitamins will be damaged, so such factors should be considered when developing the formula.

3.3 Pay attention to the anti-nutritional factors in the basic feed

There are some anti-nutritional factors in many energy feed and protein feed raw materials, which have a certain destructive effect on the nutritional factors in the feed. Such as flax cake contains anti-B6 factor; Fat oxide in soybean can destroy vitamin A and so on. When making formulas, attention should be paid to adding these nutrients.

3.4 Focus on stability factors

Most vitamins have poor stability, especially in the case of metal ions. If Cu, Fe, Mn, etc. exist in the feed, stored for 3 months, vitamin A loss of 80%, vitamin B6 loss of 20%. Therefore, the storage time in production can not be too long, and pay attention to sealing, avoiding light and other measures.

3.5 Particle size and compatibility of trace components

The particle size requirements of trace components are determined by their properties and the proportion in the full price compound feed, and the materials that are small in proportion and difficult to disperse are required to be crushed finer, otherwise the uniformity of mixing will be affected. Trace active components have a great impact on the growth of animals, but they are easy to produce chemical reactions with each other and affect their activity.

The main ways to solve the compatibility problem are: the vitamins, minerals and other components are packaged separately, and all kinds of premixed feed are added at the same time until the production of full price compound feed; To improve the stability of the active component, two methods are usually used, one is to outsource the protective layer on the easily destroyed component, and the other is to derivatives the component that is easy to affect the active substance of other components.

3.6 Security and high efficiency

Most trace elements are chemicals, and not only the effective amount but also the toxic amount should be considered when adding them. For example, copper is an effective trace element, and high doses have a growth promoting effect on animals, but when making formulas, more consideration should be given to its general use, because the amount of special effects is very close to the amount of poisoning. Another example is selenium, the content in the feed is very small, and the effective amount is very close to the toxic amount. The compound premix contains various trace elements and vitamins, and many kinds of derivatives interact with each other. For example, vitamin E and trace element selenium have synergistic effects in the body; Only when the ratio of calcium and phosphorus is right can it be efficient; The amount of iron and zinc can affect the absorption effect of copper and so on.

3.7 Choline problem

Choline chloride is a low molecular organic compound, which is necessary for the growth and development stage of young livestock. Enough choline must be added to the corn-based feed to ensure the healthy growth of livestock and poultry. Generally, 50% choline chloride powder is used as A feed additive, which has strong moisture absorption, although it is very stable, it is very destructive to the active ingredients of other additives, and has destructive effects on vitamin A, D3, K3, etc., so when used, bran, defatted rice bran, rice husk and other adsorption drying treatment should be used first to control the carrier moisture, to prevent choline moisture absorption.

3.8 Take into account weather factors

Under different climatic conditions, animals have different needs for nutrition, and the proportion of nutrient elements should be properly adjusted with the climate to make the formula more reasonable.

4 Use of premixed feed

4.1 Correctly understand the efficacy of premix

Under the conditions of intensive scale feeding, full-priced compound feed must be provided to animals. To prepare a full-value compound feed, premix is essential, should first consider the dietary crude protein, essential amino acids, energy, calcium, phosphorus, sodium, chlorine and other nutritional indicators, and then combined with scientific and reasonable premix, only in this way can play its role in improving animal production level, reducing feed consumption and health care. To distinguish the role of various nutrients in animal nutrition and their relationships, can not overemphasize the nutritional and physiological effects of premix, only in the diet of the main nutritional indicators are reasonable premise, the role of premix can be shown.

4.2 Reasonable selection of premix

Premix sold on the market is mixed, some of the quality is not qualified, unreasonable formula and other problems, in the purchase must be based on the actual situation, according to their own feed raw materials, choose to use premix according to local conditions. If you only have energy feed raw materials, you should choose total nutrient concentrate; If you have both energy feed raw materials and protein raw materials