June i, 1921 
Effect of Ration on the Development of Pigs 
297 
4. In a pig fed a ration sufficient to produce a large and rapid growth, 
producing a body weight above 225 pounds, the fat percentage increases 
as the weight increases, and the moisture percentage decreases. The 
prolonged feeding of a deficient ration produces the same result—namely, 
a pig with a high percentage of fat and a low percentage of moisture, 
provided the pig attains large size. 
5. The percentage of protein appears to decrease as the pigs increase 
in size. This is due to the large increase in percentage of fat. If the 
percentage of protein is calculated on the basis of body weight less fat, 
the percentage does not show any tendency to decrease as pigs increase 
in size. 
6. The percentage of ash appears to decrease with the increasing body 
weight. This is due to the large proportionate increase in fat. If the 
ash percentage is calculated on body weight less fat, the larger pigs have 
as high an ash content in the tissues not fat as the lighter pigs. 
7. The general character of the ration affects the composition of the 
body as follows: A large amount of protein or ash will not produce a pig 
with a high protein or ash content. Such a ration will produce a rapid 
growth, and the pig will have the same composition as a pig of the same 
size fed a ration restricted in protein or ash but whose growth took place 
over a longer period of time. The best illustrations of this fact are the 
two continuation hogs, one fed corn and ash and the other corn and 
protein-free skim milk, in comparison with the hogs in experiment II, in 
which one was fed corn and black blood albumen and the other the same 
ration plus ash. 
8. A large amount of ash in the ration will not materially influence 
the percentage of ash in the body. The ash percentage in pigs fed rations 
sufficient for growth tends to remain fairly constant, if the percentage 
is calculated on the basis of body weight less fat. 
9. There is a closer relation between a pig’s size and its composition 
than between the character of the ration and the pig’s composition. If 
growth has not been too much restricted, the composition of a slaughtered 
pig of a given weight may be used to calculate the pounds of chemical 
constituents in another pig not slaughtered. However, this must be 
done with judgment based upon knowledge regarding the history and 
condition of the pigs. 
II. CHARACTER OF RATION IN ITS EFFECT ON THE DEVELOPMENT 
OF LUNGS, HEART, LIVER, AND KIDNEYS 
That the character of the ration in respect to its nutritive properties 
has the same relative effect on the development of the internal organs as 
on the development of the body as a whole is borne out by evidence fur¬ 
nished by a number of investigators. Emmett ( 2 ) and associates fed 
three lots of pigs on low, medium, and high protein rations. The amounts 
