Feed Quality

Feed formulation

Quality control measures

Feed Quality

Quality Control in feed production is of utmost importance in the overall success and profitability of animal enterprises. There is no other factor, directly or indirectly related to the proper nutrition and high performance of animals, which is more critical than feed quality control and ration consistency. Quality has been defined as "any of the features that make something what it is" and "the degree of excellence which is a thing possesses". The degree of quality is the consistency in which feed is formulated, processed, mixed and delivered as compared to what is expected.

Obviously, a finished feed should match label claims - protein, fat, fiber, vitamins and other micro-ingredients levels, active drug level in medicated feeds and other ingredients if claimed. Animals thrive on a routine and respond better if the feed is low in nutrient variation as offered to them; and are similar in moisture content, texture and rate of energy availbility.

Feed Formulation

Quality starts with the feed formulation as it plays a major role in determining the nutrient levels in the finished feed. It is better to take the help of a qualified nutritionist, as he knows better ingredients properties, their nutrient levels, the nutrient requirements of the birds depending on the stage of development and their condition. Though the major objective of the feed formulaiton is to deliver a well balanced diet to meet the nutrient requirements of the birds, the other objective is to keep a check on the Anti-nutritional factors by limiting the use of certain ingredients.

Assuming that feeds are properly formulated, plant and company management must assure that

• All raw materials meet specified quality standards.
• There are no foreign materials in either the raw materials or the finished products.
• Processed grains and other materials meet specified particle shape and size requirments.
• The feed is manufactured and as formulated.
• Pellets and crumbles are properly sized and meet durability standards.
• There is no cross-contamination from one feed to another (especially with medicated feeds)
• There is no (or minimal) loss of vitamin potency or the potency of any other micro ingredient in storage and handling or processing.
• There are no deleterious substances or microorganisms in the feeds.
• A minimum of separation or segragation is caused by post-mixer handling
• Package net weights and bulk weights are as labeled or invoiced.
• The packaging is clean, neat and attractive.
• The customer's perception of quality is met.

Quality Control - Measures

Controlling quality in the feed industry consists of much more that an laboratory and its technicians. As important as they are, their role is to verify nutrient levels in ingredients and finished feeds, to provide technical assistance to the plant, to perform other after-the-fact analyses, and to keep the records.

Real quality control takes place on the production line, out in the plant where the action is. So quality control is the responsibility of plant personnel and their supervisors. Such in-plant quality control involves controlling raw materials, in-process materials, and finished products as well as the condition of materials handling and processing equipment and the general sanitation of the plant.

Sensory and Physical Properties

Sensory properly evaluation, including inspection of ingredient color, odor, texture, moisture, temperture, and a visual inspection for physical purity (absence of foreign material and insect infestation) enables one to quickly assess whether the ingredient should be rejected. The inspection process should be accompanied by a reference sample for comparison. Physical property evaluation usually involves testing incoming grain and feed ingredients for bulk density, purity, and texture.

BULK DENSITY of a material represents the mass per unit volume. This characteristic is commonly expressed as pounds per cubic foot (lb/ft³) or kilograms per cubic meter (kg/m³). The bulk density of a material is measured by weighing the amount of materials that fills a one-cubic-foot or one-cubic meter box. Bulk density can vary significantly for the same ingredient due to differences in particle size, moisture content, or compaction. Bulk density will determine how the ingredient will perform during batching and blending. When a feed ration required blending ingredients that differ widely in bulk density, one should ensure that the particle size of the feed ingredients is similar, use a binding agent (fat, and load the mixer using a ingredient sequence that optimizes the blending action of the mixer. For example, high density ingredients should be added early in case of vertical mixers and late in the batching sequence for horizontal mixers.

INGREDIENT PURITY refers to the absence (e.g., sand stones etc.) of contaminants. The source of these contaminants may be physical, chemical (e.g., pesticides) and microbial (e.g., fungus or mycotoxins). The use of hand sieves to inspect for physical contaminants enables rapid evaluation of material. Chemical and microbial contaminants can be performed in laboratories.

TEXTURE of an ingredient is measured visually and with sieves. Soybean meal texture is described visually as "homogeneous, free-flowing, without coarse particles or excessive fines" (AFIA, 1992). Soybean meal texture measured by sieve analysis is described as "95 to 100 % through Standard Sieve No. 10; 40 to 60 % through Standard Sieve No. 20; and a maximum 6% through Standard Sieve No. 80" (AFIA, 1992). the condit;ion of the screens in the hammer mill, the condition of the corugations and tramming of grinding and flaking rolls, and the condition of any sieving devices all affect particle size and / or shape and will affect the quality of finished products. Regular sampling of the material streams from processing equipment and quick repair of any malfunctioning equipment will assure that particle size and shape standards are met.

Microscopic evaluation

All microscopic identification is based upon relating the items seen to known material Through the use of low magnification (8 to 50 times) materials are examined and identified based on physical characteristics such as shape, color, particle size, softness, hardness and texture. Feed microscopy is a useful method for identifying impurities / contaminants and evaluating the quality of incoming ingredients. It also serves as a useful method for identifying missing ingredients in finished feed.

Nutritional Properties

Nutritional properties of feed ingredients and finished feed require laboratory analysis. This usually entails expensive analytical equipments operated by professional chemists. Many feed companies and poultry farmers use commercial labs for these analyses. Most analysis techniques involve the use of procedures tested and approved by scientific organizations such as the Association of Official Analytical chemists' (AOAC, 2000) Official Methods of Analysis. The ingredients / finished feed should be evaluated in the latoratory for proximate principles (moisture, protein, fat, fibre and ash), indivisual minerals like calcium and phosphorus (in DCP, Calcite), urease (in soybean meal), pepsin digestibility ad others depending on the ingredients. There are some established analytical variation (AV) guidelines in order to make decisions rgarding marginally acceptable products (AAFCO 2000). These variations are intended to allow for inherit variablity in sampling and analyses. They are not intended to allow for deficiencies or excesses in a product or poor analytical tecchniques. The assays results should be within the limits of the analytical variance for accepting the feed ingredient or feed for that parameter. If the assay indicates that the ingredient is outside the analytical variance, the feed does not conform to label requirements. the concentration range indicates for what inclusion rate (level) the Analytical Variation Percentages (AV%) apply; e.g., moisture AV% applies to feed containing between 3 and 40% moisture.

The feed manufactured as formulated

The accuracy of batching scales will determine whether or not the feed made is the feed formulated. Also, the condition of the mixer is critical to assure that all of the feed exiting the mixing system is the same feed that the nutritionist formulated and that the customer ordered. Batching scales and other scales / meters used to weigh ingredients (solid / liquid) must be regularly tested for their accuracy, properly maintained, and kept clean.

Mixers must be properly designed and managed to assure that they provide a complete, thorough mix of all ingredients. They must be routinely tested, filled to proper levels, and kept clean and well maintained.

Sizing of Pellets and Crumbles

Feed plants producing pelleted products need to give careful attention to the sizing and durability of those products and to the amount of fine particles in the finished feeds.

Standards for pellet sizes and durability should be established by management and adhered to by the operators of the pelleting equipment, and pellet durability testers should be provided and used.

Other factors affecting pellet quality involve the formulation; the quality of steam and the condition of the steam system; the overall condition of the pellet mill, cooler, and screener; the condition of the crumble rolls; the condition of the down stream handling system; and operating practices.

Cross - Contamination

Cross - contamination can be serious problem, especially, when medicated feeds are involved.

The major points where cross-contamination can occur are residues in a conveying equipments / elevators, leaks in material handling equipments, valves / turnhead alignment, human/mechanical errors, improper flushing of systems, incomplete cleaning of mixers.

Deleterious Substances or Microorganisms

Deleterious substances refere to harmful or, possibly, poisonous substances that might be introduced into the feed (although it is possible that such substances could come in with ingredients). Good examples are lubricants that come into contact with the feed that are not approved for food use and polychlorinated biphenols (PCBs) that may leak from PCB containing transformers, capacitors and other PCB containing equipment.

It is the responsibility of personnel to control those, and other, poisonous substances in their plant to avoid contamination of products.

Microorganisms refer, primarily, to molds that may enter the plant with the raw materials are are caused by conditions in the plant and the manufacturing processes. Detection of such microorganisms often required laboratory analysis; but, at times, they can be detected by the naked eye or the nose. Molds created, or multiplied, in the plant can, often, be avoided by operative practices and proper maintenance.

Separation of Segregation

The tendency of premixes, concentrates, supplements, and final feeds to separate / segregate in post mixer handling may be one of the most critical, yet often neglected, quality assurance problems in the feed industry.

Segregation and separation can be reduced, but not totally avoided by ;

• More positive control of the particle sizes of ingredients.
• Reducing the distance of the free fall of feeds into bins (silos)
• The use of liquid binders ( molasses, fats, etc.)
• Pelleting
• Returning collected dust immediately to the stream from which it is taken
• Grounding all equipment.

Finished Product Weights

While product weights may not be a quality consideration, but accurate weights monitoring is essential on a regular basis to satisfy the weights and measures laws and regulations, to satisfy customer requirements, and to protect the profits of the company. Packaging scales should be tested daily or more often, and truck scales should be tested, at least, monthly.

Housekeeping and Sanitation

Good housekeeping and the maintenance of a sanitary house, which is free of insects, rodents, and birds, is another aspect of in-plant quality control. Cleanliness begets cleanliness, and has strong quality implications. The control of product quality takes on greater meaning for all employees when they work in clean, neat surroundings.

Accumulations of dust, spills, scrap and all of the other things that go with an unkept house adversely affect product quality and detract from the objective of feed manufacturers to produce a better product and provide better customer service than his competitor while being a responsible member of the community.

Plant and Equipment Maintenance

Proper plant and equipment maintenance is very important to produce quality feed. It is next to impossible to expect high quality products to come from a plant that is poorly maintained. Materials handling equipment must work without leaks, spills, dust blowouts, or cross contamination; protective equipment such as magnets, scalpers and cleaners must do their job; the batch scale must weigh accurately and the mixer must mix; the processing and pelleting equipment must be in top operating conditions and the scales for packaging and bulk load out must be accurate. In the usual sense, these items may not be considered as quality control, per se; but consistent high quality cannot be achieved without them.

Quick Test for Quality Grade of fish meal

1. Place 10g of fishmeal in a 100ml tall form beaker and pour 80ml Carbon Tetrachloride into the beaker, stir and allow to settle for 5 minutes.
2. Scrape off the floating organic fraction with stainless steel spoon into filter paper. Clean off the side of the beaker and spoon and then pour off the liquid to separate the floating (organic) and the submerged (inorganic) fraction into the filter paper.
3. Place the two fractions (floating and submerged) into an 1100C oven for 10 min. then allow to cool and weigh each fraction.
4. The appropriate percentage of organic (fish flesh) and inorganic (fish bone) may be calculated.

Grading of Fish Meal

Summary

Feed ingredients should be routinely evaluated to ensure they are safe, they contain the correct amount of the specified nutrient, and to ensure the finished feed quality will optimize animal performance. Permitted Analytical Variation (PAV) guidelines help to identify deficiencies or excesses of an ingredient ina product. If the assay indicates the ingredients is outside the PAV, the feed does not conform to label requirements.