COMPOSITION OF FEEDING STUFFS. 193 



Protein or flesh forming substances are considered of 

 the highest importance in feeding animals, because they 

 supply the material required for building up the tissues 

 of the body, and for maintaining these under the wear 

 caused by the vital functions. Ordinarily the feed ra- 

 tions of most farmers are deficient in protein since most 

 of the farm-grown foods (not including clover, alfalfa, 

 peas and similar crops) contain only small amounts of 

 these substances. The feeding stuffs richest in protein 

 are, among the coarse foods, those already mentioned; 

 among the concentrated foods: cottonseed meal, lin- 

 seed meal, gluten meal, gluten feed, grano-gluten, buck- 

 wheat, middlings, and the flour-mill, brewery, and distillery 

 refuse feeds. The protein substances are also called nitro- 

 genous bodies for the reasons given above, and the other 

 organic (combustible) components in the feeding stuffs 

 are spoken of as non-nitrogenous substances. The non- 

 nitrogenous components of feeding stuffs, therefore, include 

 fat and the two following groups, crude fiber and nitrogen- 

 free extract. 



Crude fiber is the framework of the plants, forming 

 the walls of the cells. It is usually the least digestible 

 portion of plants and vegetable foods, and the larger pro- 

 portion present thereof the less valuable the food is. We 

 find, accordingly, that the fodders containing most crude 

 fiber are the cheapest foods and least prized among feed- 

 ers, as, e. g., straw of the various cereal and seed-pro- 

 ducing crops, corncobs, oats and rice hulls, cotton-seed 

 hulls, buckwheat hulls, and the like. These feeding stuffs, 

 in so far as they can be considered as such, contain as 

 a rule between 35 and 50 per cent, of crude fiber. Con- 

 centrated feeding stuffs, on the other hand, often con- 

 tain less than 5 per cent, of crude fiber, and in the cereals 

 only a couple of per cent, of crude fiber are found. 



Nitrogen-free extract is a general name for all that 

 is left of the organic matter of plants and fodders after 

 deducting the preceding group of compounds. Jt in- 

 cludes some of the most valuable constituents of feeding 

 stuffs, which make up the largest bulk of the food ma- 

 terials; first in importance among these constituents are 

 starch and sugar, and, in addition, a number of less well- 

 known substances of similar compositions, like pentosans, 

 gums, organic acids, etc. Together with crude fiber the 

 nitrogen-free extract forms the group of substances known 

 as carbohydrates. A general name for carbohydrates is 

 heat-producing substances, since this is one important 

 function which they fill; they are not as valuable for 

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