COMMERCIAL FEEDING-STUFFS 265 



proteins. But, as a matter of fact, the potential heat 

 value of the digestible part of an oil meal is certainly 

 greater than that of digestible corn meal. Under certain 

 conditions one feeding-stuff is no more fully used than 

 the other for tissue-forming purposes, and both may be 

 utilized outside of the usual wastes in the production of 

 some form of energy, ultimately heat. 



359. Classification of feeding-stuffs. The satisfac- 

 tory division of feeding-stuffs into as few as two classes, 

 according to their composition, is not possible by the use 

 of any terms whatever. Such a division is necessarily 

 based upon the relation in quantity of the protein to the 

 non-nitrogenous part, and there is an almost uniform 

 gradation of foods in protein-content from those contain- 

 ing the least to those most highly nitrogenous. Any 

 division into groups with reference to the percentage 

 amount of protein must be entirely arbitrary and should 

 take account of at least four classes of materials, other- 

 wise the extremes of each division are too widely apart. 

 Probably no more convenient and rational classification 

 of grains and grain products can be suggested than the 

 one proposed by Lindsey: 



Class I. Thirty to 45 per cent protein, 30 to 45 per 

 cent carbohydrates. The oil meals and gluten 

 meals and certain distillers' dried grains. 

 Class II. Twenty to 30 per cent of protein, 60 to 

 70 per cent carbohydrates. Gluten feeds, the lower 

 grade distillers' dried grains, dried brewers' grains, 

 maltsprouts, buckwheat middlings, and beans 

 and peas. 



Class III. Fourteen to 20 per cent protein, 70 to 75 

 per cent carbohydrates. Wheat brans and mid- 

 dlings, rye bran, and mixed feeds. 



