DEFINITIONS AND TECHNICAL CONSIDERATIONS. 359 



According to the old theory, which was that the non-nitrogenous sub- 

 stances had one principal object, namely, to furnish fuel to the body, the 

 comparative value of fat and carbohydrates was determined by the amount 

 of heat easily produced. It was calculated that one pound of fat produces 

 about 2.5 times the heat given out by one pound of carbohydrates. The per- 

 centage of fat contained in plants is very variable; for beets it is 0.1 to 0.2, 

 and in certain varieties of corn, it reaches 8 per cent., while certain oil seeds 

 contain 4(1 per cent. As this is not all extracted during the industrial methods 

 of extracting the oil, there remains a residuum containing 8 to 12 per cent. 



Fermentation is the decomposition of varied molecules under the 

 action of ferments. Decay, taken in the general acceptance of the word, is an 

 oxidation. Putrefaction involves the fermentation of nitrogenous substances 

 with the liberation of certain offensive gases. Acetic fermentation is the con- 

 version of weak alcohols into vinegar. Butyric fermentation is the conver- 

 sion of butter-fat into butyric acid. Lactic fermentation is the decomposition 

 of milk. 



Fertilizers are plant foods. 



Fibrin. A substance that does not exist in an insoluble state in the 

 circulating blood, but separates in a solid state shortly after the blood leaves 

 the body. It may be obtained by stirring blood as it flows from a living body; 

 the sticks used become covered with a white compound. It is tasteless, and 

 when dried resembles albumin. Fibrin is a proteid. 



Forage is a food for horses, but it may be applied to cattle in general and 

 is another name for feed. 



Fuel value is frequently measured in heat units or calories. One 

 pound of digestible fat is estimated at 9.200 calories; one pound digestible car- 

 bohydrates 4.200; one pound digestible protein 5.860 alories. Knowing the 

 composition of any feeding stuff, such as beets for example, in one hundred 

 pounds there are 86.5 pounds water, 1.12 pounds protein, 10.21 pounds carbo- 

 hydrates. AVhen these are burned for furnishing energy, work and the 

 maintenance of the body there would result an amount of materials yielding 

 49.445 calories. 



Gastric juice. A secretion of special glands of the stomach; it con- 

 tains an important ferment known as pepsin. 



Germs are a portion of matter, having within itself the tendency to 

 assume some living form; a spore, a seed are examples of germs. 



Gestation is the period the young need for their complete development 

 from time of their conception until birth. 



Glucose is a substance obtained from starch through the action of a 

 ferment; its varieties are numerous, among which one may mention dextrose 

 and levulose. 



Gluten meals and gluten feeds. It is difficult for the breeder 

 to exactly comprehend the difference between these two substances which 



