FORMULATION OF PREMIX AND ITS QUALITY CONTROL IN ANIMAL NUTRITION
*1Salur Srihitha
1Assistant Professor, Department of Animal Nutrition, IVS& AH, SOA DU, Bhubaneswar.
*Corresponding author- patnaiksrihithaa@gmail.com
Introduction
A premix is a blend of vitamins, trace minerals, medicaments, feed supplements, and diluents, offering a value-added solution for feeds with sustainable safety and quality. The premix industry is responsible for consistently, efficiently, and economically manufacturing high-quality premixes. Its primary goal is to deliver micro ingredients in the manner desired by the consumer. Premixing has evolved from simple hand mixing to mechanical mixing, continuous mixing, and now to computer-controlled mixing. Despite these advancements, the fundamental concept of creating a homogeneous blend of ingredients remains unchanged.
Premix manufacturing process comprises:
- Raw Materials
- Selection & Specifications
- Purchase
- Receipt & Storage
- Sampling & Analysis
- Processing
- Formulation
- Weighing
- Mixing
- Packaging
- Labeling
- Storage of Finished Premix
- RAW MATERIALS
- Selection & Specifications
Vitamins and trace minerals vary in bioavailability and stability, which are critical for selection. Stability is essential for vitamins, while bioavailability, potency, and reactivity are key for trace minerals. Ingredients should be readily available, economically viable, and contribute positively to the premix’s physical attributes. Stable derivatives, like coated vitamins, are recommended to maintain stability, and spray-dried forms improve flowability. Specifications should follow guidelines from AAFCO, AOAC, AFMA, I.P., U.S.P., etc.
- Purchase of Raw Materials
Raw materials must be bought from approved vendors and meet the nutritionist’s specifications. Each purchase should include a certificate of analysis. A purchase plan is necessary to ensure adequate inventory aligns with production needs.
- Receipt & Storage of Raw Materials
Receivers should identify product quality using quality assurance information. Sacked ingredients should be checked, assigned a reference number, and logged into stock records. Large consignments are weighed on a weighbridge; smaller ones, on an electronic balance. Proper storage involves labeling, dry locations on pallets, avoiding stacking resistance (no more than 10 bags per pallet), and regular stock rotation. Storage areas must be protected from pests, well-ventilated, sanitized, and away from direct sunlight. Temperature and humidity should be controlled based on material stability, and approved and rejected materials stored separately.
- Sampling & Analysis
Sampling follows a quality assurance program, with samples taken from different bag layers using a probe. Large consignments should be mixed before analysis. Instruments like HPLC, flame photometers, and spectrophotometers ensure accurate analysis. Trained personnel should use official methods to analyze raw materials. Materials meeting specifications are approved for formulation; those differing in particle size may be processed further, while those not meeting potency or purity standards are rejected.
- Processing
Processing modifies raw materials to meet premix specifications, primarily involving:
- Sieving
Sieving removes foreign materials and separates coarse ingredients using vibratory or mechanical sifters, which must be cleaned before and after use to prevent contamination.
- Milling
Coarse ingredients from sieving are ground using a multimill to achieve the desired particle size. Regular checks for wear on mill screens and blades are necessary. The processed material is then bagged, weighed, labeled, and stored.
- FORMULATION
- Physical Characteristics
Uniform particle size, density, and spherical shape help achieve a homogeneous mixture and minimize segregation. Trace minerals are typically coarse, while vitamins are fine powders, making homogeneous mixing challenging. Processing trace minerals to the desired size and improving flowability is essential to ensure a good mix. Proper flowability prevents bridging, caking, and product loss.
- Chemical Characteristics
The potency of vitamins, trace minerals, and medicaments must be considered. Formulators should include micronutrients based on analytical values to meet customer requirements. No materials should be added without analysis to avoid negative impacts on animal performance.
Carrier Selection
Carriers neutralize electrostatic charges, are chemically inert, compatible with other ingredients, reduce water activity, and improve stability and flowability. Common carriers include:
- Organic Carriers: Absorb moisture.
- Inorganic Carriers: Contribute to density.
- Batch Control and Manufacturing Records
Batch control sheets link the formulator to production and should include:
Nutrient requirements, ingredient selection, potency of ingredients, carrier percentage, and Packaging materials
- WEIGHING
Accurate weighing is crucial for achieving desired nutrient levels. Precision is especially important for ingredients like Selenium, where mistakes can be toxic. Balances should be calibrated daily and cleaned before and after use, with maintenance twice a year.
- MIXING
Mixing is the heart of premix manufacturing and should be divided into:
- Micro Mixing: Mixing micro ingredients (<1% of mixer capacity) in a smaller mixer.
- Macro Mixing: Blending all components in a batch mixer.
- Type of Mixer
Mixers should provide homogeneous mixtures of different particles. Horizontal or vertical mixers can be used, but specialized mixers with low CV (Coefficient of Variation) are preferred.
- Mixing Time
Optimal mixing time is determined by trial and error and coefficient of variation studies. Short mixing time leads to under-mixing, while prolonged mixing causes demixing.
- Mixing Order
Proper ingredient loading sequence affects premix quality. Regular mixer evaluation through CV studies ensures uniform mixing, with a CV value <5% indicating excellent mixing.
- PACKAGING
Packaging maintains micronutrient stability and premix integrity. It should protect against light, moisture, and oxygen, be chemically inert, provide a good printing surface, and withstand transport pressure. Ideal materials include glass containers, aluminium foil, paper, and plastics, with aluminium foil-lined multi-layered paper bags offering the best protection.
- LABELING
Labeling a premix serves two main purposes: providing complete information and differentiating it from other premixes. Different segments like layer, broiler, breeder, and dairy should use different colored labels to prevent mix-ups. A premix label should include:
- Name of the premix
- Composition
- Dosage
- Net weight (in kg)
- Regulatory/Statutory statements
- Manufacture date (month/year)
- Expiry date (month/year)
- Batch number
- Storage conditions
- Directions for use
- Manufacturer’s name, address, and logo
- Disclaimer note (if any)
Attention to detail in labeling ensures proper customer use and avoids mistakes that could affect animal performance.
- STORAGE
Quality is affected by storage conditions until distribution. Recommended steps for warehouse storage:
- Use FIFO (First In, First Out) policy
- Keep the area clean, well-lit, and ventilated
- Store premix on pallets, with no more than 10 bags per pallet
- Ensure all bags are labeled
- Control temperature and humidity below critical levels
- Keep floors, walls, and walkways clean and dry
- Keep the area pest-free
- Separate storage for sale returns or expired premix
- Proper storage conditions guarantee the premix meets its label claims.
METHODS OF QUALITY CONTROL
- Raw Materials
- Analyze raw materials before use
- Segregate approved and rejected materials
- Sieve raw materials to remove foreign or oversized particles
- Production Process
- Ensure precise weighing and inclusion of each micro-ingredient
- Perform pre-inclusion checks by quality assurance personnel
- Take corrective steps for any deviations
- Conduct post-manufacturing checks for lumps and flowability
- Eliminate cross-contamination using:
- Flushing: Run a carrier material through the system after medicated premix production
- Sequencing: Produce feeds with the same medication consecutively
- Mixer Cleanout Procedures: Clean thoroughly before and after use, with a weekly washout program
- Finished Premix
- Analyze in the laboratory for physico-chemical properties
- Dispatch only if all parameters are satisfactory
- Implement a sampling plan for analysis frequency
Producing a quality premix requires careful, professional attention. Monitoring critical points minimizes deviations and ensures product quality is built into the process, not just tested in the final product.
References:
- Holt, D. and Aldrich, C.G. 2021. Evaluation of Mixing Efficacy of Carriers for Supplemental Nutrient Premixes in Animal Feed. Kansas Agricultural Experiment Station Research Reports, 7(10), p.17.
- Zinn, R.A., 2004. A guide to feed mixing. University of California, Davis.
- Micro ingredient Premixing, Keeping Current. BASF Corporation.
