General Principles of Live-stock Production 31 
food-producing animal but the gain made on a hundred 
pounds of feed by a growing colt is possibly even lower 
than from the steer. These figures are very generally 
used by the boosters of the dairy and hog industry as 
evidence that the dairy cow or the pig is a very much 
more profitable animal than the steer or sheep. The 
amount of digestible nutrients required, however, to make 
a hundred pounds of gain is only one side of the question. 
In all animals there is a very great difference in the 
proportion of feed which must be derived from concen- 
trates as compared with the proportion which is derived 
from the roughages and pastures. For example, beef 
cattle, range horses, and range sheep can be and are raised 
very successfully and profitably without the use of any 
concentrates whatever. Even farm sheep will use but a 
very small amount of grain, deriving practically all of 
their sustenance from hay and pasture. This is very 
significant in view of the fact that one hundred pounds 
of digestible nutrients from grain will cost $1.50 to $2; 
from hay about 50 cents to 75 cents; and from pasture, 
5 cents to 25 cents. The pig must derive as much as 75 
to 90 per cent of his sustenance from the grains or concen- 
trates. The dairy cow requires less concentrates than the 
hog, and on the other hand very much more than beef 
cattle and sheep. 
Another very important factor in grazing countries is 
the extent to which these animals can utilize the pastures 
and ranges. For example, we find that horses, beef 
cattle, and sheep are sometimes run on range the year 
round, and derive their entire support from this source 
without the use of any other feed whatever. This is not 
the general custom, since they are usually given some feed 
for winter, but probably from two-thirds to three-fourths 
