142 
IOWA ACADEMY OF SCIENCE Voi,. XXVIII, 1921 
exist and so long as we do not know why they exist, then just that 
much longer they must exist because we do not know the necessary 
weapons with which to offset them. 
Briefly speaking, our more favorable general deductions from 
the experiments we have run thus far are : 
First — Corn oil cake meal added to a corn and tankage ration 
is quite efficient — it saves considerable corn and tankage when 
properly fed. The mixture of corn oil cake meal with tankage 
looks favorable, and under certain economic conditions should be 
more favorably considered than “Free-Choice” feeding. 
Second — Corn oil cake meal takes the place of tankage up to 
about half of the daily allowance ; in other words it displaces half 
of the daily tankage fed. On the basis of a hundred pounds of 
gain it really displaces somewhat more than half the tankage, this 
being particularly true when it .is added to a corn and tankage ra- 
tion, although this is not true when the meal is added to a hominy 
and tankage ration. 
Third — Corn oil cake meal seems to fit in excellently with the 
corn and tankage ration; largely, we think, because it supplies 
certain deficiencies in said ration. 
Fourth— Hominy feed, which is really corn concentrated in bran 
and germs and starch through the removal of the flinty portion or 
the gluten of the kernel, shows up quite well in comparison with 
corn, although our tests have not shown it to be the equal of corn. 
Fifth — Hominy feed requires less tankage daily than does corn 
or approximately four-fifths as much.' On the basis of pounds 
tankage to feed with a hundred pounds of corn or hominy the lat- 
ter requires about 2/3 as much as the former; or if twelve pounds 
balanced a hundred pounds of corn then about eight pounds 
would do for hominy feed. 
Sixths — In such a nutritional complexity we find in all our ra- 
tions for pigs we must expect that even with our best rations there 
is a certain limiting factor or factors, and the addition of this or 
these factors will tend to make the ration more efficient not only in 
increasing daily gains but in decreasing the feed required for a 
unit of gain. Animal Husbandmen should always be on the look- 
out for the “long-comings” as well as the shortcomings of rations. 
If a ration is deficient in certain particulars then through the use 
of the proper feed which supplies these deficiencies, and this in the 
proper quantity, the ration may be improved. It is well to keep 
in the front line trenches so as to catch a clear vision of the possi- 
bilities of correct combinations. 
