Agricultural Chemistry. 



as the grains, and consequently cannot be expected to furnish 

 available energy for severe labor in sufficient quantity, compatible 

 with the storage capacity of the digestive apparatus of the horse. 



There has been a strongly established opinion that oats are 

 pre-eminently the horse feed and must form a generous propor- 

 tion of the grain ration; that they give life and nerve to the 

 animal. At one time the discovery of a special compound, 

 "Avenin," resident in the oat kernel and endowed with these 

 stimulating properties, was announced. This is now disproved 

 and it is becoming more and more evident that other grains can be 

 substituted for oats with no impairment to the animal's well 

 being. 



Fattening requirements. To increase body weight it is neces- 

 sary that the food supply be in excess of that required for main- 

 tenance and for the production of heat and work. When such 

 an excess is given, the protein and ash are in part converted into 

 new tissue, and the fats, carbohydrates and possibly proteins, 

 stored up in the form of fat. Feeding a young animal an excess 

 will promote the further development of bone and muscle, while 

 in the case of the mature animal, the increase will come almost 

 wholly from the deposition of fat in the tissues. In both in- 

 stances fat forms the largest proportion of the increase. This is 

 shown in the following figures : 



Composition of Increase When Steers are Fattening. 



Water Ash Protein Fat 

 Per cent Per cent Per cent Per cent 



Oxen, fattening very young 32-37 2.25 10 50-55 



Matured animals, final period.. 25-30 1.5 7-8 60-65 



These figures serve to illustrate how the food is used, and that 

 the increase is largely fat formation. A satisfactory gain of 2 

 pounds per day would then mean a storage of 1.3 to 1.5 pounds 

 of dry substance, of which about 0.2 pound is protein. From the 

 fact that carbohydrates can serve as sources of fat, it is evident 

 that the non-protein part of a ration may be the chief source of 

 the increase laid on by a fattening animal. The protein require- 



