REFERENCES :>41 



being the most concentrated form in the body. There is 

 also some evidence to suppose that dextrose is formed from 

 fat. Proteins are the source of cell material in the body 

 and are useful in building up new cells and repairing old 

 cells. Thev also serve as a source of fuel when dextrose 

 and fats are not present in sufficient quantities. From the 

 non-nitrogenous residue of proteins carbohydrates are 

 formed. The inorganic elements serve as necessary con- 

 stituents of protoplasm and give rigidity to the skeleton in 

 their mineral form. They are also present in the tissues 

 and fluids of the body, regulating the tone of the muscles 

 and nerves, and the osmotic pressure of the cells. 



The value of food may be expressed in terms of per- 

 centage digestibility, called coefficients of digestion, which 

 are determined by a chemical analysis and represent the 

 amount of material actually absorbed by the body. Further 

 advances in the expression of food values have resulted in 

 the use of a respiration calorimeter whereby all income 

 and outgo of the animal can be measured in addition to the 

 heat production. Since the value of foods to the animal can 

 be expressed in terms of heat units this form of expression 

 is now used very largely in calculating animal rations. 



REFERENCES 



Armsby. Principles of Animal Nutrition. 



Brubaker. Text Book of Physiology. 



Halligan. Elementary Treatise on Stock Feeds and Feeding. 



Henry. Feeds and Feeding. 



Jordan. The Feeding of Animals. 



Sherman. Chemistry of Food and Nutrition. 



Smith. Manual of Veterinary Physiology. 



Starling. Human Physiology. 



