124 THE FAMILY HOESE. 



farmers, who axe now paying high prices for the identical elements 

 in commercial fertilizers which they are permitting to go to loss in 

 their own barnyards. 



FEEDING. 



The otudy of the subject of food elements, and their relation to 

 the animal system, has been greatly neglected. Of late years science 

 has been doing much in this Une of work, but there is a great deal 

 to be done yet. Although the animal body is so complex in struct- 

 ure, yet chemistry has divided it in a general way into nitrogenous, 

 non-nitrogenous, and mineral matters. Since these substances are 

 continually being destroyed in the body in forming materials for 

 growth, in generating heat, and in producing force, it is necessary 

 that the animal should receive substances similar to those destroyed, 

 so that these may be assimilated by the tissues and fluids of the body 

 to replace those lost and to enable the vital actions to continue. 



The object of feeding is to supply the animal with the various 

 elements which enter into its composition, and since the nitrogenous 

 (albuminoids, or protein) and non-nitrogenous (carbohydrates) sub- 

 stances vary only in narrow limits, and since the rate at which each 

 IS destroyed in the body is also fixed, it follows that the food which 

 the animal receives should also contain these nutrients in the right 

 proportion. The food given to an animal may contain all the nutri- 

 ents named, but it may not contain them in the right proportion to sup- 

 ply the animal organism. Some are rich in albuminoids, while others 

 are composed largely of carbohydrates. Hence, in an economical 

 point of view, we should combine these foods to form a mixture in 

 the right proportion to satisfy the needs of the animal system. A 

 large part of the animal body is composed of albuminoids, and as 

 it is impossible for the animal system to convert carbohydrates into 

 albuminoids, the sole source is from those plants containing the 

 albuminoids. The Germans estimate a pound of digestible albumi- 

 noids to cost on an average five times as much as a pound of digesti- 

 ble carbohydrates ; it is readily seen that economy requires the least 

 proportion of the former consistent with perfect nutrition. The 

 quantity of carbohydrates which a horse requires, depends upon the 

 latitude and the season. As carbon and hydrogen are the heat-pro- 

 ducing elements, it follows that the colder the climate the greater 

 proportion of carbohydrates is needed. We have mentioned the 

 importance of the albuminoids in animal economy. It is evident, 

 then, that the proportion of albuminoids which the feed contains is 

 an important element in determining its value ; and those foods 

 which contain them in the largest quantity are, other things being 



