Feeds are grouped into eight classes on the basis of their composition in the way they are used for formulating diets (Table 6).
By necessity these classes are arbitrary, and in borderline cases the feed is assigned to a class according to the most common use made of it in usual feeding practice. For instance, some bran samples may contain over 18 percent fibre and more than 20 percent protein and yet are classed as forages because they are normally used in this way.
Table 6 Classes of Feeds by Composition and Usage
|Code||Class Description 1/|
|1||Dry forages and roughages||Hay; straw; fodder (aerial part); stover (aerial part without ears, without husks or aerial part without heads); other products with more than 18 percent crude fibre (dry basis); HULLS|
|This class includes all forages and roughages cut and cured. Forages or roughages are low in net energy per unit weight, usually because of the high fibre content. Thus, such products as SEED COATS, PODS, rice BRAN, etc. are included in this group.|
|2||Pasture, range plants, and forages fed green||Included in this group are all forage feeds either not cut (including feeds cured on the stem) or cut and fed fresh.|
|3||Silages||This class includes only ensiled forages (MAIZE, ALFALFA, GRASS, etc.), but not ensiled FISH, GRAIN, ROOTS and TUBERS.|
|4||Energy feeds||Included in this group are products with less than 20 percent protein (dry basis) and less than 18 percent crude fibre (dry basis) as, for example, FISH, GRAIN, mill by-products,|
|5||Protein supplements||This class includes products which contain 20 percent or more of protein (dry basis) from animal origin (including ensiled products) as well as oil meals, GLUTEN, etc.|
|7||Vitamin supplements (including ensiled yeast)|
|8||Additives||This class includes further feed supplements as antibiotics, colouring materials, flavours, hormones and medicants.|