78 A STUDY OF FARM ANIMALS 



in the food is converted into glucose. This sugar is then 

 taken up by the circulation and carried to the liver, where 

 it is again changed somewhat, and from here is distributed 

 over the body as needed. The carbohydrates are largely 

 used in the system to furnish the energy necessary in work, 

 and to make fat. Interesting experiments with animals 

 show that more fat is stored in the body than can be sup- 

 plied by the protein and fat in the food. Dr. W. H. Jordan, 

 of the New York Experiment Station, proved that carbo- 

 hydrates are used to form part of the fat in the milk of the 

 cow. If animals are fed enough foods rich in digestible car- 

 bohydrates, the fat in the body will not tend to diminish in 

 amount. In other words, such foods protect or conserve 

 the body fat. Ihe carbohydrates are also regarded as great 

 sources of heat and energy. This phase of the subject will 

 be explained a little further on. Feeds containing plenty of 

 carbohydrates cost less for the dry matter in them than any 

 other feeds, and are valuable for filling the stomach. Sheep 

 and oxen must be fed a quantity of roughage, as a filler, if 

 they are to do well. 



The fat in the food undergoes no important change in 

 the stomach, but in the small intestine, through action of 

 the bile poured in from the liver, and the pancreatic juice, it 

 is converted into glycerine and fatty acids. The alkali in the 

 bile unites with the latter, forming a soap. In this changed 

 form of glycerine and soap, the fat finds its way through the 

 intestinal wall into very minute projections, known as villi, 

 through which it enters into the lacteals and thence on as a 

 milky fluid known as chyle into the blood circulation near 

 the shoulder. In this changed form the fat of the food be- 

 comes a part of the body fat. The fat of the body is usually 

 made from the fat and the carbohydrates of the feed, though 

 it may be produced to a small extent from protein. There 

 is usually but little fat in the roughages fed to stock 



The mineral matter in the food is taken up in the small 



