Feed Assessment
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 Programme 2: Feed Assessment and Monitoring Programme (FAMP)Features: |
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| Samples required | Tests conducted | ||||||||||||||||||||
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Mixer Performance Studies
Modern premix and feed mill mixing equipment are capable of producing a very homogeneous feed product, with as little as two to three minutes mixing time. Proper mixing is essential in ensuring uniform distribution of ingredients added to the feed, which directly influences the animal performance. However, proper mixer performance is dependent on a number of factors, which include: |
Measurement of Mixer Performance To ensure the mixing efficiency, CV (coefficient of variation) study is the appropriate test. Coefficient of variation is an expression for sample variability relative to the mean. It is defined as: C.V. % = SD / Mean x 100% Where SD is Standard Deviation |
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Indicator: Salt Samples: 10 feed samples about 100g each The general guideline for evaluating mixer CV’s is:
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Particle Size Studies
Feed manufacturers produce different types of feed in terms of particle size such as fine, medium and/or coarse to cater the need of different stages or classes of poultry.
Birds perform their best on diets having uniform particle size. Particle size of ingredients is important in the overall process of handling and mixing of ingredients to manufacture formulated feeds (diets) and is critical in achieving optimal utilization by animals. Particle size influences: |
Determining and expressing particle size: The particle size (diameter), number of particles and surface area per gram of ground feed are calculated by tabulation of sieving data (using sieve no. 8,10, 14, 28, 48, 100 and 150) and calculation of log normal distribution of particles of a ground feed. The average particle size on a sieve is calculated as the geometric mean diameter of the sieves through which the particles passed and upon which they were retained. The values obtained for geometric mean, particle size and standard deviation are used to calculate the total surface area of a sample or total number of particles per gram in a sample. Samples: 500g of ground and mixed sample before processing (pelleting) for each type of feed manufactured Guidelines: |
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Thus, particle size of feedstuffs and diets becomes an important variable that influences the efficiency of feed utilized. The distribution of particle size in a feed must be defined and evaluated in order to maintain a consistent feed formulation day-after-day. It is useful in studying the effect of processing on performance of a feed ingredient or diet, and to use as a quality control check on grinding or rolling. The use of “fine”, “medium”, or “coarse” may not be an adequate description of particle size distribution in feed ingredients or diets. These terms are relative and have limited use.
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Starter – 4 to 5 mm and |
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Soybean Protein Quality
Feed manufacturers normally carry out Urease activity test for Soybean meal to detect whether it has been properly processed or not to remove the anti nutritional factors. However, whereas the Urease index is useful to determine if the soybean meal has been heated enough to reduce the anti – nutritional factors, it is not very useful in determining if Soybean meal has been over-processed. Protein Solubility Index (PSI) is a good index for determining the over-processing of Soybean meal which is not reflected by the Urease Index. PSI normally remains high for Soya processed under optimum heat condition and starts reducing in case of excessive heat treatment. It has been observed that Soya processed under optimum heat treatment provides the best growth and performance. Protein Dispersibility Index (PDI) is more sensitive than Urease index or KOH solubility for determining the optimum amount of heat processing of Soybean meal.
Birds perform their best on diets having uniform particle size. Particle size of ingredients is important in the overall process of handling and mixing of ingredients to manufacture formulated feeds (diets) and is critical in achieving optimal utilization by animals. |
Other studies in soybean meal:
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| Assessment of Calcium Status in Feed | |||||||||||||||||||||
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Next to energy birds adjust their feed intake based on Calcium requirement. In other words, birds will eat more feed for want of Calcium. This is called 'Calcium Hunger'. Rapid growth potential of broilers, requires enough feed to be consumed and hence the feed manufacturer has to keep the Calcium level at the marginal level. Further, in addition to Calcite / Marble powder and DCP, the raw material used in the feed manufacturing supplies Calcium to the bird. Feed manufacturers calculate the calcium content for raw materials as per the NRC standards published. However, this may differ for the raw materials available in the country. Say for example, in India the estimated calcium content of maize/corn is more than 0.08% as against the published value of 0.02% as per NRC. This increased content of Calcium in maize/corn significantly contributes Calcium to the bird. Excess Calcium will bind to Phosphorus (2 molecules of Calcium will bind to one molecule of phosphorus) and make phosphorus, a costly input for feed manufacturers unavailable to bird. Further majority of the feed additives used in poultry feed are based on calcium carbonate carrier, which also contributes significant amount of calcium to the diet. Keeping these factors in mind, the assessment of calcium in the raw materials and final feed is important. |
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| Pellet Quality Studies | |||||||||||||||||||||
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These tests indicated below are subjective tests that are not a good measure of pellet quality
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Pellet Durability Index
Pelleted feed quality is defined using the pellet durability index (PDI). This is a simple test in which the pelleted feed is tumbled in a defined period of time that simulates the transfer and handling of feed (Fairfield, 1994). The ratio of fines to pellets in the sample after tumbling is the PDI. Thus, feed with a higher PDI means that the manufactured pellets are more likely to remain intact prior to feeding. |
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Water Activity of the Feed
The water activity of feed is a very important aspect of feed, determining its quality during storage. The growth of the various microorganisms stops at a given level of water activity and a knowledge of this level is important for feed manufacturers. Definition: Water activity is simply the ratio of the water vapour pressure in any kind of feed system to the water vapour pressure of pure water at the same temperature. Water activity (aw) = P product / P water The lowest limit for growth in feed or any other item is around aw 0.6. In the narrow range between aw 1 and aw 0.6 a large number of microorganisms can grow which are potentially dangerous to feed and in turn for the birds consuming this feed. Water activity of feed should be below 0.6 to check the microbial growth of the feed. Other Studies |
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Grains (Maize/Corn, Bajra, Jowar etc.):
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Fat Source (Vegetable Oil / Tallow):
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Vegetable Protein Source (Soy meal, Full Fat Soya, Ground Nut meal etc.):
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Other Feed Raw materials / Additives: (a) Shell Grit / Marble Powder/ Calcite
(b)DCP
(d) L Lysine hydrochloride Finished feed samples Subjected to proximate analysis (Moisture, Sand & Silica, Crude protein, Crude fat, Crude fibre, Salt and Total ash), and Calcium and Phosphorus testing. |
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FAMP Guidelines
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