52 Milk and Its Products 
Last of all, the ideal ration should be cheap, not 
necessarily in the sense of being made up of low 
grade or low cost foods, but from the standpoint of 
furnishing the largest possible amount of digestible 
nutrients at the lowest cost. Home-grown foods 
ordinarily cost the dairyman less than commercial 
foods, and the milk producer will ordinarily feed most 
economically who uses the largest possible amount of 
home-grown foods. On the other hand, commercial 
foods in nearly all markets, if well selected and care- 
fully purchased, may be fed at a profit if the cows 
are well selected: and productive. Market fluctuations 
in various localities make it possible for the consumer 
of commercial foods to effect considerable saving in 
his feed bills, and the dairyman can scarcely be called 
an intelligent one that does not keep well-informed 
in regard to local market conditions and prices, with 
respect to commercial foods, and vary his purchases 
accordingly. 
Selection of breed.—The development of the milk- 
ing powers of the dairy cow has been the result of 
evolution and selection. So far as is known, all of 
the breeds of dairy cattle have been brought up to 
their present capacity for production by constantly 
selecting the highest producing individuals, and raising 
the offspring from these on both sides; that is to say, 
the selection of the bull from a high-producing cow 
‘has been considered quite as important as the raising 
of female calves of such cows, in securing improve- 
ment. The importance of a high- producing animal 
has already been discussed. In order to produce such 
