^ 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 stuils 

 contain only a small quantity of fat, but this component 

 is nevertheless of considerable importance in the feeding 

 of animals. 



Organic Matter 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-S) 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 2\ 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, 

 ind 1.6 per cent digestible fat (see following table): 



1.6x2.2 = 3.52; 34.9 + 3.52 = 38.42; 38.42 -4- 6.5 = s.g* 



Nutritive ratio, i ; 5.9. 



