PRINCIPLES OF LIVESTOCK BREEDING. 57 
difference in butterfat production, relative to the size of the animals 
and their cost of upkeep, is probably not very great. The differences 
between good and poor strains within each breed are much more 
important than differences between two breeds. 
QUALITY IN MEAT. 
The world-wide trend toward a falling per capita production of 
meat and the rising prices relative to other foods make the more 
economical production of meat a pressing problem. Both better 
methods of management and the improvement of the native stock 
by grading are of the greatest importance in this connection. The 
differences between purebred and scrub stock and the advantages 
to be expected by the grading up of the latter, however, are often 
misunderstood. The improvement is not primarily in size or even 
in the apparent economy of gains. The three most important 
breeds of beef cattle — Shorthorn, Hereford, and Aberdeen Angus — 
are indeed of large size, and when crossed with scrub beef cows or 
with milk cows which are undersized by heredity and not merely 
stunted by lack of proper feeding, they produce great improvement 
in this respect. Shorthorn and Hereford bulls have done wonders 
for the western range cattle in this way as well as in others. The 
pure breeds of swine and the larger breeds of sheep have also often 
been used to advantage to increase the size of native stock. There 
are, however, many large-sized scrubs. 
The Holstein-Friesian cattle probably have the largest bony 
framework of all the breeds, but are not the best beef cattle. Feeding 
tests at experiment stations have often shown very little difference 
in either rate or gain or the cost per pound of gain when purebred 
or high-grade beef steers were compared with steers of scrub or 
dairy breeding. Holstein-Friesian steers, as might be expected, 
have shown up especially well in such tests. Similar results have 
been obtained in comparing purebred swine with "razorbacks" 
raised under the same conditions. 
In the tests with cattle, however, the animals of beef type and 
breeding usually finished out into a class for which the market 
would pay considerably more than for the finished scrub or dairy 
steers. The per cent which the dressed weight forms of the live 
weight depends largely on the degree of fattening, and varies from 
40 per cent in thin cows to 70 in the most highly finished steers. 
Under the same conditions steers of beef breeding usually dress out 
from 1 to 5 per cent more than common or dairy steers. There is 
also a slight difference in the size of the cuts from different parts of 
the carcass. Nature tends to develop most flesh in the muscles 
which do the most work. In the beef breeds of cattle, animals have 
been selected for breeding in which there was as much flesh as pos- 
