Mineral Content of Southern Poultry Feeds 
41 
GENERAL SUMMARY 
From Table XXI we note that the grains, such as corn, wheat, and 
oats, as well as egg (including the shell), rice, bread, fish, and hominy, 
are acid. The wheat middlings, in six analyses, on account of the 
high sodium and potassium content, is base. Green feeds such as rape, 
cabbage, darrots, beets, turnips, potatoes, spinach, and lettuce are 
base. Seeds of the legumes such as velvet bean, soybean, peanut, and 
peas are base. Bone meal on account of its high calcium content as 
well as other base forming elements, is highly base. Limestone grit is 
very highly base so also is crushed oyster shell, though to a less extent. 
The animal feeds containing bone, such as meat and bone meal, and 
digester tankage, are base. The calcium of the egg shell does not quite 
overcome the acid of the albumin of the egg. Dried milk functions as 
base for the lactic acid is oxidized to carbonic acid which is. thrown off 
by the lungs, leaving the basic residue of mineral salts. Dried skim 
milk or dried buttermilk is therefore quite base in function. Dried 
blood, on account of its magnesium, calcium, and sodium content, is 
moderately base. 
In these studies there have been arranged eleven feed mixtures for 
acid-base studies. The first seven are North Carolina Experiment 
Station formulae and the last four are'those of Professor Rice. The 
mixtures that contain considerable amounts of either dried milk, meat 
and bone meal, or digester tankage are quite base. The mixture con¬ 
taining soybean meal is approximately as much base as the grain 
mixture is acid so that equal amounts would approximately balance 
so far as acid-base content is concerned. The peanut meal mixture 
is slightly below the soybean meal mixture and the blood meal comes 
slightly below the peanut meal. 
We note from Table XXII that the grain mixture contains 12 per 
cent protein calories and the ground feed mixtures contain from 19 
per cent in the case of the non-fat extracted peanut meal mixture to 
31 per cent in the case of the blood meal ration. We note by a study of 
Table XXIII which gives the total intake of each mixture for each 
period that the final percentage protein calories run from 13 to 22. 
As a comparison of rations for humans, we may again refer to the study 
of army rations during the late World War in which the percentage 
protein calories ran from 10 to 18. Dr. Osborne (Osborne and Mendel, 
J. Biol. Chem. 1916, XL, 16) found that 12.5 per cent protein calories 
produced maximum growth in rats. The indications are that the kinds 
as well as the quantities of proteins are essential factors. While the 
kinds of amino-acids and vitamines are important factors in addition 
