The Bulletin. 



11 



By coefficient of digestion is meant the percentage of a given nutrient 

 That is digestible. This is determined by actual feeding experiments 

 with animals. The coefficients in the following table were obtained by 

 digestion experiments with ruminants. 



DIGESTION CO-EFFICIENTS FOR COMMERCIAL FEEDS.* 



Linseed meal (oil meal) 



Cotton-seed meal 



Gluten feed -. 



Dried distillers' grains 



Corn meal --. 



Hominy feed 



Oats, whole 



Wheat bran 



Wheat middlings 



Rye feed 



Corn and oat feeds, low grade 



Molasses beet pulp- 



Molasses feed 



*Lindsey, Mass. Expt. 18th Kept. 



Every feed dealer, to protect himself and his trade, should insist on 

 feeds being shipped him in strict compliance with the law. If he will 

 do this and not buy from those manufacturers who do not comply with 

 the law, he will save considerable trouble and inconvenience by having 

 his feeds seized and confiscated by feed inspectors. 



THE CHEMISTRY OF FEEDS. 



In the chemical analysis of feeds the following determinations are 

 made : protein, fat, fiber, nitrogen-free extract, moisture and ash. With- 

 out going into a detailed description of the chemical properties of these 

 classes of substances, the following general discussion will be found val- 

 uable in interpreting the analysis of commercial feeds : 



PROTEIN. 



The term protein or crude protein as used in feed analysis includes all 

 the nitrogenous compounds contained in the feed. These compounds 

 are divided, chemically, into two classes — the true proteins and the 

 amido compounds. Familiar examples of the true proteins are the 

 white of egg, lean meat and the gluten of flour. In seeds and cereal, 

 products the amido compounds are present in very small amount, and 

 hence all the nitrogen is regarded as present in the form of protein. 

 The protein compounds contain, approximately, 16 per cent of nitro- 

 gen, so to determine the amount of protein in a feed the total amount of 

 nitrogen is determined, and this, multiplied by the factor 6.25, gives 

 the amount of protein. 



