HOW TO PRODUCE FARM ANIMALS 207 



a yearly alternation of crops on the same field. But at the 

 same time this rotation furnishes roughage in the form of 

 wheat straw and corn stover, concentrates in the form of 

 corn grain, and protein and roughage in the form of clover. 

 The rotation may be varied somewhat by using oats and 

 timothy on small areas to take care of the special needs of 

 work horses. In some such way the farm may be made to 

 attain a high efficiency in production both of crops and 

 farm animals, and at the same time may maintain this ef- 

 ficiency by keeping up the fertility of the soil. 



Principles of feeding farm animals. In order to secure 

 the best results in the feeding of farm, animals and also to 

 furnish a variety of feeding material in sufficient quantities, 

 it is necessary to follow certain principles of stock feeding 

 established by experience and scientific study. 



All farm animals need feed for two purposes; to supply 

 energy, and to supply material for growth or for replacing 

 parts of used-up tissues. The combination of feed materials 

 used by an animal is called a ration, which also refers to 

 the amount of feed used in one day. If the ration is just 

 enough to keep the animal alive and healthy it is called a 

 maintenance ration. But if, in addition to the amount needed 

 for maintenance, it supplies a surplus for producing fat in 

 hogs, milk in dairy cattle, or labor in horses, it is known as 

 a productive ration. 



A ration which meets the needs of an animal must contain 

 three substances: protein, carbohydrates, and fats. Protein 

 is a name given to a class of substances such as white of egg, 

 lean of meat, gluten of flour, etc. Carbohydrate refers to 

 starch, sugar, and cellulose; and fats to oily substances such 

 as tallow, lard, butter, and to the oil of seeds, such as cotton 

 seed, corn, etc. 



