1.2.2 Chemical evaluation
An analytical laboratory for precise estimation of nutrient contents and contaminant is of utmost important. Analyze the feeds for proximate principles. This indicates possible constraints on usage due to the presence of excessive content of crude fibre, fat or total ash. Low crude protein (CP) and high crude fibre (CF) of oil seed meals indicates adulteration with fibrous materials. The high CP alone is indicative of adulteration with urea and or some inferior quality oil seed meals like mahua, castor or karanj cake. The amount of acid insoluble ash is a good guide to the amount of sand or other dirt which may be present.
It is also desirable to determine free fatty acid content of oily materials as this will affect palatability due to rancidity of oils. The specifications of various feeds and feed ingredients are laid down by the Bureau of Indian Standards (BIS) which acts as guidelines for the supplier, buyers and the users. The commonly used analytical procedures for analysis of feeds and feed ingredients are given in part II of this manual.
Ingredient specifications
Ingredient specifications are essential in feed quality assurance programme. Specifications serve as the basis from which purchasing agreements are written, feeds are formulated and ingredient inspections are performed. Ingredient description and general nutritional specifications may be found in BIS specifications for feeds and feed ingredients in India. Specifications of the feeds must be as comprehensive as possible, realistic and transmitted to the seller. These are the “measuring sticks” to which the delivered material must conform. Specifications are the foundation of a quality assurance programme because they serve as an understanding between nutritionist, purchase and production departments. A list of BIS specifications for feed and feed ingredients is presented as appendix in part III of this manual.