70 LIVESTOCK ON THE FARM 



An interesting point in connection with fat as a feed for 

 animals is the fact that a farmer can grow much more wheat, 

 oats or barley per acre than he can of flax. 



As shown previously, when a plant grows it requires energy 

 from the sun in the form of heat, light, and other rays. As 

 also shown previously, fat is a much more concentrated sub- 

 stance than protein or carbohj^drates. An acre of soil gets 

 just so much energy from the sun and no more. Flax, there- 

 fore, which is very much richer in fat than the other feeds 

 mentioned cannot produce as many bushels per acre as these 

 other crops which contain less fat and more carbohydrates 

 and protein. 



MINERAL MATTER 



Mineral matter is material like salt, lime, ashes, iron, soil 

 particles, etc. When plants grow they take up some of the 

 chemical elements which are in the soil. These are used by 

 the plants in doing their work and are then deposited in the 

 cells and tissues of the plant. 



Animals also need mineral substances. But animals have 

 greater need of these mineral substances than have plants. 

 They need these materials not only for the digestion, absorp- 

 tion, resorbtion, etc., but they need them also for bone 

 construction. 



While the mineral substances, and there are a number of 

 them, compose the smallest part of the ration, they are, at the 

 same time, among the most important parts. It cannot be 

 said that one of the substances, water, carbohydrate, protein, 

 fat or mineral matter is more important than any other be 

 cause they are all needed. The animal cannot do well unless 

 they are all present in sufficient amount. In fact, the animal 

 machine would refuse to work altogether, if any one of them 

 were left out. 



Animals can get along without mineral matter in their daily 

 feed for from one to six months, but during this time they are 

 using substances of this kind previously stored in the body. 

 They, therefore, grow constantly weaker. They get weaker 

 in bone and weaker generally and if the mineral substances 

 are not supplied they will become ill and die. Many 



