The Production, Use, and Considerations of Premixes

Premixed feed is a homogeneous mixture made by blending various additives of the same category or different types of additives in a certain proportion. Although premixed feed constitutes only a small portion of the total feed, it plays an extremely important role in the feeding effectiveness of complete feeds. A scientific premixed feed formula is key to the production of premix. To produce high-quality premix, it is necessary not only to have a scientific formula but also high-quality raw materials, precise equipment processes, and a set of comprehensive management measures. Premixed feed is not just a simple product; it is a highly technical product, representing the integration of raw material quality testing, nutritional formulation design, and livestock management techniques. In order to further promote and popularize premixed feed technology, this article provides a brief overview of the production technology and usage of premixed feeds.

The Purpose, Characteristics, and Function of Premixed Feeds

The purpose of producing premixed feeds is to ensure that trace components and additives are evenly dispersed throughout the compound feed after being diluted and expanded. Premixed feeds can be produced either by specialized manufacturers or in dedicated production workshops attached to compound feed plants.

Premixed feeds have the following characteristics:

1. Complex Composition: High-quality premixed feeds generally contain 6 to 7 types of trace elements, over 15 types of vitamins, 2 types of amino acids, 1 to 2 types of drugs, and other additives (such as antioxidants and antifungal agents). The properties and effects of these feed additives vary, making their compatibility complex.
2. Small Amount, Large Effect: Premixed feeds typically account for 0.5% to 5% of the compound feed. Despite the small amount used, they play a significant role in improving animal performance, enhancing feed conversion rates, and preserving feed.
3. Not for Direct Feeding: The active ingredients in premixed feeds are highly concentrated, usually several dozen to several hundred times the amount required by animals. Direct feeding can easily lead to animal poisoning.

The functions of premixed feeds are mainly:

1. Ensuring even distribution of trace additives in the compound feed.
2. Compensating for and improving the undesirable characteristics of trace components, such as instability, hygroscopicity, and static adsorption.
3. Standardizing the level of additive inclusion.
4. Simplifying the production process for general feed mills and reducing investment.

Key Points of Premixed Feed Production Technology

2.1 Using Advanced Formulations The formulation of premixed feeds is the core of the production technology. It is designed by animal nutrition experts from specialized premix manufacturers based on the nutritional needs of animals at different growth and production stages. The formulation takes into account the basic nutritional content of domestic feed ingredients, following the principles of supplementing deficiencies, economic rationality, and high efficiency with low-cost ingredients. External environmental factors and processing techniques are also considered in the design. On one hand, the formulation should choose appropriate and adequate additives based on the nutritional requirements, farming conditions, and user needs. On the other hand, processing needs must be considered; for most non-safety-affecting ingredients, such as nutritional additives, mastering appropriate quantities is key to the formulation process. For medicinal additives and some sensitive ingredients (like selenium and copper), usage quantities and methods must be based on solid scientific data and practical experience, as errors in their application can have serious consequences. The ratio of ingredients is a crucial factor influencing the quality of premixed feeds. The ratio of effective components to diluents, the proportion of trace elements, and the balance of active components should all be precise. The formulation should not be fixed and should be adjusted based on market feedback, local conditions, seasonal changes, and the latest technology and product information, ensuring that premixed feed products remain aligned with national conditions and practical production needs.

2.2 Selecting High-Quality Raw Materials The quality of raw materials significantly impacts the effectiveness of premixed feeds. The basic requirements for high-quality raw materials are high purity and the absence of toxic or harmful substances, with the most critical factor being the content of active ingredients. Additives such as vitamin A and vitamin C, which are easily destroyed, should be measured to determine their appropriate inclusion levels. Raw materials containing trace elements must have high biological activity, stable physical properties, and low levels of toxic substances. Some additives can affect other ingredients, and their quality and form should be carefully considered. For example, ferrous sulfate heptahydrate has high hygroscopicity and can destroy vitamin A, whereas ferrous sulfate monohydrate has a less significant impact on vitamin A, and adding protectants further minimizes the damage. Premixed feed manufacturers should select high-quality raw materials and conduct precise measurements of their quality and efficacy. When choosing vitamins, it is essential to select those with high biological value and to consider climate factors, such as using mononitrate thiamine instead of thiamine hydrochloride in hot and humid summers. For trace elements, factors like content, particle size, crystallization water, and levels of harmful substances must also be taken into account. For medicinal feed additives, safety issues should be prioritized, ensuring the correct usage period, withdrawal period, and precautions based on the manufacturer's instructions and trial materials.

2.3 Using Optimal Carriers and Dilutants Carriers are particles that carry or adsorb trace active ingredients and are non-active substances in premixed feeds. The selection of carriers should follow these principles: high chemical stability, non-damaging to adsorbed materials, suitable particle size for easy mixing with complete feed, and low cost. The particle size of the carrier should be between 0.177mm and 0.59mm, with density close to that of the trace components it carries. In compound premixes, the carrier's density should be the average of the densities of the trace components. When mixing carriers and additives, adding 1.5% vegetable oil can enhance the carrier's adhesiveness. The water content of the carrier should be controlled at 8-10%, and it should not damage the activity of the active ingredients. The carrier's pH should be near neutral. Common carriers include shell powder, wheat bran, corn, rice bran, de-oiled rice bran, stone powder, zeolite powder, and salt. Dilutants are non-active substances that reduce the concentration of active ingredients in premixes and prevent interactions between trace particles. Dilutants should have low moisture content (below 10%), be non-hygroscopic and non-clumping, with a particle size between 0.05mm and 0.6mm. They should be smooth, have good flowability, and have a pH between 5.5 and 7.5, with no static charge. They must be animal-safe, non-toxic, and stable.

2.4 Raw Material Pretreatment Vitamins are easily affected by oxygen, moisture, heat, light, and metal ions, leading to a decrease in their activity. To meet production requirements, all vitamin additives must undergo special pretreatment to maintain their stability and activity. Emulsification techniques can be used to form fine particles that are evenly dispersed in the matrix, followed by coating techniques to form microcapsules with gelatin coating. This treatment improves the resistance to mechanical processing, oxidation, and enhances mixing properties. Trace element additives, such as copper, iron, manganese, and zinc, often require pretreatment to improve their physical properties and meet processing requirements. Pretreatment methods include drying, anti-caking agents, coating, granulation, and pre-grinding.

2.5 Using High-Precision Production Equipment A scientific formulation depends on accurate measurement and batching. To ensure strict adherence to formulation requirements, advanced measurement equipment and rational processes are necessary. Premixed feed production requires high accuracy and stability in various batching and measuring devices, and regular calibration and management of the equipment are essential. For additives that are used in small quantities and affect safety, such as selenium and copper, careful attention should be given to their measurement and dilution. Mixers are the most important equipment in premixed feed production. Different premixed feed varieties require different types of mixers, such as gravity-free particle mixers, cone mixers, double-spiral ring mixers, double-shaft paddle mixers, and fast residue-free mixers. Common requirements for mixers include: high mixing efficiency, short optimal stirring time, uniform mixing, easy cleaning, low residuals, good sealing, low leakage, and static electricity prevention.

2.6 Ensuring Uniform Mixing Although feed mixing is a physical process, it is essential to select the right equipment, mixing time, and appropriate carriers or diluents, as raw materials have significant differences in density and characteristics. The process should be as simple as possible, with the aim of achieving uniform mixing. In high-quality premixed feeds, all components should be uniformly distributed, and any sample tested should have a composition ratio that matches the formulation. However, variations between different samples and batches can exist due to various factors. Poor uniformity in premixed feeds means that the actual intake by animals may not align with the formulated supply, affecting the efficacy of the additives and overall feed performance. This is especially important for ingredients where the difference between safe and toxic dosages is small, such as trace components. Uniformity is a critical quality indicator for premixed feeds, and the coefficient of variation (CV) should be less than 7%.

2.7 Introducing the HACCP Management System With increasing attention to food safety, particularly in meat products, it is necessary to implement the HACCP management system in premixed feed production. The first step is to analyze potential hazard factors in the feed production process, identify critical control points, and establish control standards. Then, effective control measures should be implemented, and testing methods and procedures must be developed to detect deviations from the standards. Corrective actions should be taken promptly, and production processes and control methods should be adjusted as needed. The HACCP system should be thoroughly verified. By implementing HACCP, feed manufacturers can enhance quality control awareness and improve production standards, ultimately advancing the overall production level of premixed feeds.

Issues to Note in Production    

3.1 Relying on Feeding Standards    

Feeding standards are based on the nutritional requirements of animals for different purposes and can serve as a reference for formulating premixed feed recipes. In specific applications, broader knowledge of animal nutrition is necessary.

• The nutritional requirements in the feeding standards represent the total amount of the same nutrient provided by various components, not the amount to be added.
• It is best to use raw materials for premixed feeds that have directly measured ingredients while considering the synergistic and antagonistic effects between different nutrients.
• The nutritional requirements in the feeding standards represent the minimum needs of the animal. Formulation should consider real conditions and ensure adequate quantities are added to meet the true nutritional needs of animals under varying conditions.

3.2 Considering Process and Processing Losses    

During the processing of premixed feeds, strict adherence to the formulation is necessary to ensure accurate ingredient inclusion. Different methods of adding ingredients should be employed based on their properties, and uniform mixing must be ensured (CV less than 7%). In the feed processing process (e.g., grinding, pelleting), some nutrients like vitamins may be damaged, so these factors must be considered during formulation.

3.3 Attention to Anti-Nutritional Factors in Base Feeds    

Many energy and protein feed ingredients contain anti-nutritional factors that can destroy the nutritional value of the feed. For example, flaxseed contains anti-B6 factors, and soybean contains compounds that damage vitamin A. These factors should be considered when formulating recipes.

3.4 Considering Stability Factors    

Many vitamins are unstable, and their degradation worsens in the presence of metal ions. For example, when feed containing Cu, Fe, Mn, etc., is stored for 3 months, vitamin A loses 80% of its activity, and vitamin B6 loses 20%. Therefore, feed storage time should be minimized, and appropriate measures such as sealing and light protection should be taken.

3.5 Particle Size and Compatibility of Trace Elements    

The required particle size of trace elements depends on their properties and their proportion in the complete feed. For trace ingredients that are difficult to disperse but are used in small amounts, finer grinding

Usage of Premixed Feed

4.1 Correct Understanding of the Efficacy of Premixes In intensive farming conditions, it is essential to provide animals with a complete compound feed. To formulate such a feed, premixes are indispensable. The formulation should first consider nutritional indicators such as crude protein, essential amino acids, energy, calcium, phosphorus, sodium, and chloride in the diet, and then combine these with scientifically and rationally selected premixes. Only then can the premix contribute to improving animal production levels, reducing feed consumption, and promoting health. It is important to understand the role of various nutrients in animal nutrition and their interrelationships. The nutritional and physiological effects of premixes should not be overstated. The efficacy of a premix can only be realized when the main nutritional indicators in the diet are reasonable.

4.2 Rational Selection of Premixes Premixes available on the market vary in quality, with some being substandard or having unreasonable formulations. When purchasing, one should base the choice on the actual situation, selecting premixes according to the feed raw materials available.

• If only energy feed materials are available, a full-nutrient concentrate should be chosen.
• If both energy and protein feed materials are available, a compound premix with an addition rate of 4-5% can be selected.
• For feed manufacturers, compound premixes with an addition rate of 1-3% or high-tech classified premixes with an addition rate of 0.1-0.5% produced by specialized premix manufacturers should be chosen. Choose premixes produced by manufacturers with strong technical capabilities, comprehensive product specifications, stable quality, and good after-sales service. The premix formulation should be selected based on local agricultural products, and the characteristics of available base materials.

4.3 Strictly Identifying Quality When purchasing premixes, products from reputable manufacturers should be prioritized. It is essential to carefully check whether the packaging is standardized and the label is complete. The label should include the following items:

• Product name
• Applicable stage
• Main ingredients
• Type and content of added medicines
• Addition ratio
• Usage instructions
• Production date
• Expiry date
• Standards followed
• Approval number
• Manufacturer's name, address, and phone number The product quality should also be assessed by sensory inspection. A qualified premix should have a consistent particle size, uniform color, and be free from unusual odors, mold, moisture absorption, or clumping.

4.4 Clear Identification of the Intended Use Premixes should be selected based on the type of livestock and poultry, as well as their growth stage. Carefully check the species and applicable stages indicated on the label.

4.5 Accurate Dosage Premixes should be mixed thoroughly with other feeds according to the instructions. Generally, the premix makes up 0.5-6% of the total amount of compound feed. Accurate measurement is necessary, as using too little will not achieve the desired effect, while using too much not only wastes the product but may also cause poisoning.

4.6 Thorough Mixing with Base Feeds Premixes must be thoroughly and evenly mixed with other feeds before feeding. It is best to prepare the feed immediately before feeding, and any mixed feed should be used up at once.

4.7 Correct Storage Proper storage conditions are essential to maintain the freshness of the premix. Unopened premixes should be stored in a ventilated, cool, and dry place, and should be categorized accordingly. Once opened, they should be used as soon as possible and should not be stored for an extended period. During use, care should be taken to keep the premix sealed to prevent moisture, which could reduce the effectiveness of the active ingredients.

Summary

Premixes are high-tech products formulated based on the theoretical needs for animal growth, development, and nutrition, taking into account various relevant factors. Advanced equipment and techniques are used to combine and evenly mix various vitamins, trace elements, amino acids, growth-promoting factors, and other ingredients using carriers and diluents. These products cover most of the nutritional needs of animals and, when mixed with protein and energy feeds, can effectively balance and optimize nutritional effects, fully meeting the growth and production requirements of animals.

However, it is important to note that there are still some issues in the production and use of premixes in China, such as the widespread use of the same trace element premix in different contexts, problems with the mixing and packaging of components in compound premixes, and concerns over the use of high-copper, high-zinc, and arsenic-based products. With the advancement of technology and societal progress, these issues are expected to be gradually addressed. Livestock producers must ensure they correctly select and properly use premixes to fully leverage their high-efficiency nutritional benefits.