392 
IOWA ACADEMY OF SCIENCE 
cl^eased. Note that the corn increases from 76 per cent of the 
entire ration on the 108th day to 99.47 per cent on the 258th 
day, and then gradually decreases to ‘^make room’^ for the in- 
creasing meat meal and charcoal. As the pigs unfold in their 
development they vary their intake of food nutrients. In other 
words they vary the daily ‘‘Bill of Materials”. 
The charcoal consumption, although Plate XLI does not show 
it, it is well to note in passing, was at a minimum during the 
larger part of the feeding period, but when the pigs persisted 
in eating largely of corn, decreasing to a low point on the meat 
meal and oil meal, the pigs began to eat of the charcoal of 
maplewood. In practice we find that when fattening hogs are 
receiving a “corn alone” ration, charcoal is quite beneficial. 
Herein the appetite of the pig gives us a clue for further investi- 
gations: Is it true that pigs receiving corn alone require char- 
coal for optimum development; whereas those on corn and meat 
meal diet do not necessarily require it, at least not to such a 
marked extent? 
The oats and oil meal eaten are seen gradually to decrease 
(see Plate XLI), the animals tending to visit the oats compart- 
ment but very, very seldom after the age of five months ; whereas 
oil meal was scarcely touched after the seventh month. The 
great preference of the pig for corn grain and meat meal is 
demonstrated. 
The pigs in Lot II weighed 316 pounds when they were eight 
months and four days of age, a very unusual record. Lot I, 
heretofore spoken of, weighed 304 pounds at the same age; 
whereas Lot III lifted the weigh beam at 303 pounds. It can 
thus be seen that, in so far as weights are concerned, all three 
lots did very creditably. As compared to ordinary systems'"^^ 
of feeding these weights are really exceptional. While this is 
not direct evidence that these “Free-Choice” fed pigs were fed 
to the maximum of advantage, yet the indications are favorable. 
It is to be emphasized that the' feed consumption of Lots I 
and III, not given, is in general in very close accord with that 
of Lot II. This is impressed by careful reference to Plates 
XLII, XLIII, and XLIV. 
By the use of his Illinois standard (see Plates XLII, XLIII, 
and XLIV), worked out after a number of years of careful in- 
33For further discussion of practice see Evvard, John M. : The Iowa Sys- 
tem of Self-Feeding Swine, 1914, Corn Belt Meat Producers’ Association. 
Report, 1914, pp. 56-69. 
