24 PRINCIPLES OF FEEDING FARM ANIMALS 



The importance of vitamins lies in the fact that body growth can 

 only take place when they are present in the food. Animals fed 

 all necessary food components in pure form (protein, fat, carbo- 

 hydrates,, mineral matter) will not make a normal body growth 

 until some vitamin-containing food is added to the diet. A number 

 of diseases, as scurvy, beriberi, pellagra, etc., will also occur when- 

 ever vitamins are not supplied in the diet. Since milk contains 

 ample amounts of vitamins, the importance of this food, and of 

 dairy products in general, in the feeding of man, especially for in- 

 fants and children, is readily seen. 2 



Ash Materials. The animal body contains the same ash ma- 

 terials as are found in plants, and as a general proposition the ele- 

 ments essential to the life of plants are also essential to animal life. 

 In the case of two elements, sodium and chlorin, it is a question 

 whether they are absolutely essential to plants, but since they are 

 present in all soils, plants always contain an ample supply of both 

 elements. It is definitely known, however, that both sodium and 

 chlorin are essential to the growth of animals and to the continued 

 exercise of their vital functions. We shall see that gastric juice, one 

 of the digestive fluids of the body, contains free hydrochloric acid ; 

 this acid comes from the sodium chloride (common salt) found in 

 the feed of the animals or eaten directly by them. Animals fed 

 largely coarse feeds receive a sufficient amount of salt in the feed 

 to supply their wants, but when fed much grain or other concen- 

 trates low in mineral matter, they need more salt than that contained 

 in the feed ; all farm animals relish salt greatly, and the practice of 

 " salting " livestock has, therefore, become quite general. 



Salt improves the appetite of the animals and increases the flow 

 of digestive juices; it promotes and regulates digestion and should, 

 therefore, be furnished in ample amounts. In the case of milch 

 cows at least, a supply of salt in addition to that in the feed is es- 

 sential to their continued health, both because of their large feed 

 consumption, especially grain feed, and because of the amount of 

 chlorin removed in the milk. It is a general practice among dairy- 

 farmers to supply about an ounce of salt daily per cow, placing it 

 before them in the mangers or giving them free access to salt. Unless 

 milch cows receive salt, abnormal conditions will soon appear and 

 there will be a gradual reduction in vitality of the animals which 

 will result in a general breakdown after a period varying with dif- 

 ferent cows from a month to more than a year. 3 



2 McCollum, "The Newer Knowledge of Nutrition," New York, 1918; 

 Sci. Monthly, 1918, p. 179; Jr. Soc. Chem. Ind., 1918, p. 53; Gue. Breeders' 

 Jr., XVI, p. 234. 



"Wisconsin Report 22, p. 154. 



