20 BULLETIN 378, XJ. S. DEPARTMENT OE AGRICULTURE. 
of fishermen, could well be handled at small by-product plants at- 
tached to canneries, at the time of the preparation of meal from the 
waste, or in larger factories devoted entirely to the manufacture of 
meal. It would seem that in this new field for the use of fish meal 
for feeding purposes an outlet may have been found for the use of 
this outcast of the fish tribe and that it can at last be turned into 
material having a commercial and economic value. 
The addition of this fish in liberal quantities to waste material 
from canneries, comprising heads, tails, fins, and only a small pro- 
portion of the meat portion of the fish, would greatly increase the 
feeding value of the resulting meal. 
Attention should be called to the difference in composition — par- 
ticularly of the protein material — of fish meal made from whole fish 
or from waste containing a large portion of the edible part of the 
fish, and of a fish meal prepared from waste composed entirely of the 
heads, tails, and fins. In the latter case gelatin or glue derived from 
the collogen of the cartilage, bones, and fins, will predominate as the 
protein constituent, and a meal thus prepared will not have so high 
a feeding value as one in which the protein derived from the meat or 
flesh of the fish predominates. 
In instances where waste deficient in the protein constituents of 
whole fish is available, the dogfish will serve to good advantage as 
a means of supplying this deficiency and will increase the content 
of essential tissue-building material. 
GENERAL CONCLUSIONS. 
The universally favorable results obtained in the feeding of fish 
meal appear to warrant its extended use as a supplementary feeding 
stuff. 
Laboratory tests have shown that the coefficients of digestibility 
of the principal constituents of fish meal — the protein and fat — are 
high, and the feeding experiments have all shown it to be as valuable 
as many other high-protein concentrates with which it has been 
compared. t 
From the feeding experiments it appears that there has not been 
just cause for the assumption that the feeding of fish meal of good 
quality imparts a fishy taint to such products as milk, butter, eggs, 
and meat. When the meal is fed in proper quantities, as a supple- 
mentary feed with other feeds, apparently no deleterious effects are 
noticeable in regard to taint or flavor of fish. There is a possibility 
that it may impart its flavor to the products of animals or fowls 
when it is fed to them in too large quantities. Even under these 
circumstances its use would be warranted, as the feeding of the meal 
can be discontinued a sufficient length of time during the final fatten- 
ing period to eliminate any objectionable taint. 
