242 LIVESTOCK ON THE FARM 



The factor of waste is absent under such conditions. As grain 

 is fed into the machine, more fuel is required in the engine; 

 some to handle the material that is being fed into the separa- 

 tor, some to run the machine itself. 



When grain is fed into the separator only in normal quan- 

 tities, the effectiveness of the machine is greatest; that is, 

 under these conditions, more of the grain is saved. As the 

 machine is crowded toward the limit of its capacity, more 

 grain is left in the straw, and more passes across the sieve be- 

 cause a larger part of the sieve becomes clogged, allowing a 

 smaller quantity of grain to pass through into the sack or 

 wagon. More grain is also required to furnish the necessary 

 fuel in the engine. When the amount of grain fed into the 

 separator is again reduced, the machine gradually becomes 

 more effective; that is, as a smaller amount of grain is fed into 

 the separator, less fuel is required in the engine, more grain 

 is threshed out of the straw, and more of the material that has 

 clogged the sieve is saved. But it takes time for all of the 

 material that has become lodged in the meshes of the sieve to 

 shake out so' as to allow the machine to become as effective as 

 it was at the beginning. A thresher is more effective when not 

 crowded to its fullest capacity, and it is also more effective 

 when the moderate quantity thus handled is approached from 

 below rather than from above. In pig feeding, however, the 

 factor of waste apparently can never be entirely eliminated 

 when once established, as in the thresher. 



Sources of Protein.^ — The sources of protein on the farm for 

 swine feeding are alfalfa, clover, milk, soy beans, peas, oil meal 

 and tankage. The latter two are commercial feeds and while 

 they are good and profitable at moderate prices, they should not 

 be resorted to except when home-grown feeds are not available. 



Alfalfa and clover are roughages and furnish both protein 

 and bulk. This in itself is a very important consideration be- 

 cause a ration containing some bulk is better than a ration 

 made up entirely of concentrates. Bulky feeds make it im- 

 possible for the young and rapidly growing pig to get sufficient 

 protein therefrom for maximum and most economical growth. 

 On this account it is necessary to add to the ration some pro- 

 tein in the form of a concentrate or of the other nitrogenous 



