THE FEEDS 357 



is hardness. If there is not an abundance of gravel where 

 the birds may pick up pebbles, grit should be constantly 

 supplied. Fowls prefer shiny particles of sparkling grit to 

 that which is dull. Commercially, grit appears on the market 

 under many names, but is made chiefly from crushed quartz, 

 feldspar, phosphate rock, and granite. Oyster shell, which is 

 very valuable as a source of ash, is not hard enough to serve 

 as grit. 



The size of grit must of necessity be regulated by the 

 size of the stock fed. Commercially, it is usually offered as 

 chick size, medium, and large size grit. 



W. P. Wheeler' found that mixing sand with the food of 

 newly hatched chicks resulted in better health for the chicks 

 and a more efficient use of food. He also found that ground 

 oyster shell could not take the place of sand. 



Salt. — Salt in some quantity is necessary to all farm 

 animals. It adds palatability to the ration and is generally 

 supposed to aid digestion. It should be fed with caution. 

 Wheeler^ reports experiments in the feeding of salt in which 

 he found no bad results until he reached a proportion of 6.3 

 ounces per 100 hens. At that point diarrhea appeared. 

 This disappeared when the amount of salt was reduced one- 

 third. He recommended salt at the rate of 5 ounces per 

 100 pounds of feed for mature stock, and that no salt be fed 

 young stock until after they are two months old. 



Shell (Oyster) . — ^The necessity of a supply of lime or calcium 

 for the formation of egg shells is shown by Wieke (as reported 

 by H. J. Wheeler^) in the following analysis of egg shells: 



* Per cent. 

 Carbonate of lime . . 93 . 71 



Carbonate of magnesia . 1 . 39 



Phosphate of lime ... . 76 



Organic substance . . . ... 4 . 24 



W. P. Wheeler* found that where oyster shell was the only 

 mineral feed given hens, aside from that contained in the 



» New York Bulletin No. 242. 



2 Twenty-sixth Annual Report, New York Experiment Station. 



' Rhode Island Bulletin No. 84. 



• Twenty-sixth Annual Report, New York Experiment Station. 



