CORN AND ITS BY-PRODUCTS 185 
usually available are oyster shells, limestone grit, and dry ground 
bone. Their composition is shown in Table VI. 
TaBLE VI.—Composition of Sources of Lime (pounds in 100). 
Equivalent , 
Sources of lime. Protein. Lime (CaO). to carbonate Pr gn 
Crushed oyster shells. . id 53 95 0.08 
Limestone grit........ Me 18 32 10 
Dry ground bone...... 26 27 49 24.18 
Phosphate.—Less than four per cent of the body of the adult 
bird is mineral matter, consisting almost entirely of phosphate 
of lime, and the use of phosphate has been found to be especially 
profitable and practical in rations for growing chicks. Bone ash is 
supplied in the form of granulated bone, bone meal, or cut bone. 
Organic Feeds.—The feeds grouped under this heading are: 
(1) Grains and their by-products, which are termed concentrated 
feeds, and (2) grasses, hay, and straw, which are called roughage. 
Concentrates take their name from the fact that high nutrient 
content is represented in small bulk; and roughage from the fact 
that a larger amount of fibre or cellulose is present, and a larger 
bulk represents only a small nutrient content. 
The leading grains must be relied upon mainly for poultry. 
The different organic feeds naturally group themselves into the 
following divisions: Grains and their by-products, animal feeds, 
hays, grasses, and vegetables. As the by-products are closely 
associated with the grains from which they are derived, these two 
groups will be discussed together. 
Corn and its by-products are the principal sources of feed for 
poultry, the great value of this grain lying in its available energy, 
due to its high percentage of easily digested carbohydrates and 
fat and the absence of all poisonous substances. 
There are three races of corn which are available in different 
sections for poultry feeding. These are designated by the terms 
dent, flint, and sweet. Dent ‘and flint corns are practically the 
same in chemical composition. The flint variety is usually found 
in the cool climates, along the northern border of the corn belt, 
being extensively raised in New England. Dent corn flourishes 
where the higher temperatures prevail. In palatability and usage 
dent and flint corn are practically the same. Corn, being largely 
starch and oil, is essentially a feed designed to produce heat. 
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