APPETITE OF SWINE 
399 
The gradual tendency of animals to widen their ration as the 
period progresses is self evident. It has not been demonstrated 
heretofore to our knowledge that animals allowed free expres- 
sion as regards satisfaction of appetite would widen their ra- 
tion as these have done, only to narrow it again in the later 
stages of fattening. This is evidently what happens with grow- 
ing pigs and the reason is probably not far to seek. From the 
80th up to the 255th day of age the ‘‘appetite’^ fed pigs did 
gradually widen the ratio from about 1 :4 to 1 :7.7, after which 
time it was gradually narrowed until it reached a ratio of 1 SA 
on the 34:5th day. (This is disregarding the drop in Lot III on 
the 275th day, which is discussed in a footnote.^^^) One would 
think that with a narrower ration the pigs would, of course, 
want more protein per unit live weight, but reference to Plate 
XLII shows this not to be the case because the protein actually 
decreases gradually. Reference to the carbohydrate equivalent, 
Plate XLIII, likewise demonstrates, that the carbohydrates per 
thousand poqnds live weight eaten are gradually lessening at 
this time although comparatively at a more rapid rate than the 
protein. 
Now, what is the reason for this narrowing of the ration, 
after the maximum ‘^wideness’’ had been approached? Refer- 
ence to Plate XLI shows that there is a gradiial lessening in the 
amount of total grain feed eaten after the 193d day, at which 
time a maximum of a little over 9.7 pounds was reached until 
on the 350th day the amount of grain feed eaten had decreased 
to about 5.5 pounds, a decrease in consumption of more than 
45 per cent. The total protein consumption likewise, has 
gradually declined after the 193d day although this decline has 
been somewhat slow from the 300th to the 355th day. The car- 
bohydrate equivalent has lessened markedly after the 193d day, 
and this decrease continues to the finish of the experiment, the 
^oThis is brought about by a somewhat marked increase in the amount of 
protein eaten in the meat meal at this time (275th day — see Plate XLII). But 
why this heavier meat meal consumption? This observation was simultan- 
eously made : The pigs in Lots I and II began to eat charcoal at this time, 
and ate more in a day than during their whole previous lives. But not so 
with Lot III, as they seemingly did not realize that it was charcoal that was 
needed, and not meat product. However, at about the 275th day this group 
too tardily discovered that the “charcoal box was the place wherein to seek 
satisfaction of appetite,” and shortly we note a decrease again in the meat 
consumption. . Note, however, that Lots I and II, especially so the latter, 
started to eat large quantities of the charcoal on the 265th day, or just a few 
days after they had reached the maximum of almost 100 pounds (respective- 
ly 98.25 and 99.47 pounds) of corn out of every 100 pounds of all feeds (ex- 
cluding water) eaten. Did the corn diet “set up” a peculiar combination of 
conditions that called for charcoal as a corrective, or antidote, or what 
was it ? 
