Maintaining the Herd 55 
in their full productive capacity; if there is abundant 
opportunity for selection and purchase near at hand; 
if there is a reasonably good market for cows that are 
undesirable, and if one has reasonable skill in select- 
ing, and good ability in bargaining, a herd of high- 
productive ‘capacity may be- more easily and more 
cheaply maintained in this way than by attempting to 
raise young animals to replace those that are worn out. 
The other method of maintaining the herd is, of 
course, by raising calves to supply the place of old 
cows that are no longer profitable. Such a herd will 
always contain a considerable number of young ani- 
mals, that have not yet reached full development, and, 
therefore, such a herd will seldom equal in average 
production per animal a herd that is maintained wholly 
by purchase. At the same time, a greater degree of 
uniformity of type may be maintained where the ani- 
mals are raised. If land is abundant and cheap, the 
cost of raising a calf, up to the time that she becomes 
a fully developed cow, will be less than that of pur- 
ehasing a similar animal outright. Through force of 
circumstances by far the greater number of dairymen 
must rely on raising the calves necessary to maintain 
the herd. This being the case, the ordinary dairyman 
will need to provide himself with the services of a bull 
suitable to produce useful dairy cows. In most cases 
he will need to own this bull, so that the question of 
the selection and care of the breeding bull has an 
important bearing upon the maintenance of the dairy 
herd. 
Selection of the bull.—It goes without question that 
