186 CHEMISTRY OF FARM PRACTICE 



133. Rice. Rice is used as a human food over a large 

 part of the world. In the process of milling, there are 

 several by-products which are of value as stock feed. The 

 rough rice is put through a machine which removes the 

 hull and leaves the rice grain intact. The grains are then 

 rubbed by mechanical means until the skin and the flour 

 at the eye of grain are removed. Some grains which are 

 inferior are so abraded that they grind up. The material 

 is then sifted to remove the flour, and the fine chaff is re- 

 moved by fanning. This chaff is then mixed with the flour, 

 forming what is known as rice flour or bran. 



Rice polish is obtained by the operation that rubs off 

 the last covering layer and a good part of the starch. This 

 is accomplished mechanically by rubbing the rice against 

 pieces of moose hide or sheepskin. Rice polish contains a 

 considerable amount of starch. 



Rice meal may prove injurious to the intestines of hogs, 

 on account of the irritation caused by fine splinters of 

 silicious material that find their way from the hulls into the 

 meal. 



2. HIGHLY NITROGENOUS CONCENTRATES 



134. Cottonseed Meal. Cottonseed meal, a by-product 

 of the cottonseed oil mills, is the cheapest source of digestible 

 protein that can be bought in the form of a concentrate. 

 On this account, there is grave danger of too liberal use of 

 it, especially in the Southern States. Where used in 

 limited quantities, it is a most excellent source of protein. 

 Enough cottonseed hulls to reduce the nitrogen to about the 

 equivalent of 7 per cent of ammonia is often added, the 

 crushers claiming that this promotes a more complete 

 removal of the oil. The cottonseed cake used for domestic 

 purposes is usually ground and placed in 100-pound sacks, 

 which is a convenient weight for handling. Cottonseed 

 meal is high in protein and fat, but low in digestible carbo- 

 hydrates. 



