2 .... AGRICULTURE. 



hydrates. A general name for carbohydrates is heat-produc- 

 ing substances, as against flesh-fortning substances, i.e., 

 nitrogenous compounds, the names indicating the main 

 offices of the substances in animal nutrition. 



Ether Extract, or crude fat {oil) includes a group of com- 

 pounds dissolved out by ether in the analysis of foods; fat 

 forms the main part of the extract; most feeding stuffs 

 contain only a small quantity of fat, but this component 

 is nevertheless of considerable importance in the feeding 

 of animals. 



Organic ^Tatter signifies the combustible portion of chemi- 

 cally dry feeding stuffs, i.e., all the components given in the 

 preceding except water and ash. 



Digestible Components. — The food stuffs used in the feed- 

 ing of farm animals are only partly of direct value to the 

 animals, the portion which their digestive fluids are unable 

 to dissolve being voided in the excrements. The digesti- 

 bility of fodders has been determined by direct experiments 

 with different kinds of farm animals, in this country or 

 abroad. The digestion coefficients (see pp. 6-8) mean the 

 percentages of any one component which have been found 

 to be digested by the animals experimented on. 



Nutritive Ratio signifies the ratio between the digestible 

 nitrogenous and non-nitrogenous components in a feeding 

 stuff, or a combination of such. As fat has been found to 

 yield about 2.2 times more heat, when burned, than do starch, 

 sugar, and other carbohydrates, the per cent of digestible 

 fat in a food is multiplied by 2.2 when the nutritive ratio is 

 to be calculated; the product is added to the per cent of 

 digestible carbohydrates (nitrogen-free extract -|- crude 

 fiber), and this sum is divided by the per cent of digestible 

 protein. (The factor i\ or 2\ is sometimes used for obtain- 

 ing "the starch equivalent" of fat.) 



Example: Clover hay contains on the average 6.5 per cent 

 digestible protein, 34.9 per cent digestible carbohydrates, and 

 1.6 per cent digestible fat (see following table): 



1.6X2.2 = 3.52; 34.9+3.52 = 38.42; 38.42-^6.5 = 5.9. 



Nutritive ratio, i : 5.9. 



