194 FEEDING STUFFS 
Mixed Feeds and Manufactured Products.—Certain classes 
of products designed for poultry feeding are manufactured in 
different sections of the United States. In some instances it has 
not been proved that these materials are objectionable, but in 
nearly every case experiments show that the ingredients which 
are supposed to be furnished can be more economically secured 
from natural sources. A great variety of so-called ready-mixed 
feeds are advertised. They are supposed to contain a given amount 
of nutrients in a very economical form. In practice a great major- 
ity of such feeds should be avoided, as many of them are adultera- 
tions containing a large amount of filler and make-weight material. 
Analyses made at various experiment stations show the following 
materials to be occasionally used in such feeds: Oat hulls, ground 
peanut shucks, cut straw and hay, sand, and other foreign sub- 
stances, which are used to increase the bulk and the weight of 
the feed. It is a much more economical practice for poultry- 
men to purchase the standard grains and by-products and do 
their own mixing. Any plan which will lower the grain bill will 
be helpful. 
Animal Feeds.—Leading authorities agree that, for the best 
results in poultry feeding, the birds should be given protein and 
other nutrients from animal as well as from vegetable sources. 
All feeding experiments show that where animal protein is entirely 
withheld the birds do not make so good nor economical growth, 
and cannot be made to produce as many eggs in a given period. 
There are several sources from which nutrients of an animal origin 
can be obtained. Their use depends somewhat on location and 
upon the price of the different ingredients in local markets. 
Meat scrap is undoubtedly the most popular of the different 
forms of animal matter for poultry. There are many grades on 
the market, which may be grouped as high grade or low grade. 
The high-grade meat usually contains about 60 per cent of 
protein and the low-grade about 35 to 40 per cent. It will always 
be found more economical to purchase high-grade meat scrap, as 
the price per pound of protein will be less. Then,-too, the high- 
grade meat is usually more sanitary and better prepared. A com- 
mercial practice is to cook the carcasses or pieces of meat under 
steam pressure for a given number of hours, to render out the fat. 
This sterilizes them completely and kills any bacteria of a detri- 
mental nature which might be present. Scrap prepared in this 
way is not apt to contain poisonous matter. On the other hand, 
