24 PRINCIPLES OF FEEDING FARM ANIMALS 



ties in which the lipoids occur in the animal body, they appear to be 

 of the greatest importance in the nutrition of animals, especially 

 in the case of growing animals. 



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

 terials as are found in plants, and it holds true, as a general proposi- 

 tion, that the elements which are essential to the life of plants are 

 also essential to animal life. In the case of two elements, sodium 

 and chlorin, the evidence at hand is not sufficient to show that 

 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 concentrates 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 

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

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

 chlorin that is daily removed in the milk. The general practice 

 among dairy farmers is to supply about an ounce of salt daily per 

 cow, placing it before them in the mangers or giving them access 

 to salt in the yard. Unless milch cows have access to salt, abnormal 

 conditions will soon appear which will result in a general break- 

 down after a period varying with different cows from a month to 

 more than a year. The gradual reduction in vitality of the animals 

 which is brought about by a lack of salt, as shown by Babcock, is 

 evidenced by " loss of appetite, a generally haggard appearance, 

 lusterless eye, a rough coat, and a very rapid decline in both 

 weight and yield of milk." : 



Phosphate of Lime. The mineral components present in the 

 animal body in the largest quantities are lime and phosphoric acid. 

 They make up the skeleton of the body and form about 80 per 



2 Wisconsin Report 22, p. 154. 



