MILK PRODUCTION 429 



The adaptation of breed to the environment should 

 never be ignored. That relatively light breeds fare better 

 on rugged lands and pastures extensive in production is 

 now generally conceded. It is also generally accepted that 

 the Ayrshire and the Devon have higher adaptation for 

 stern climates than some at least of the other breeds. 



The milk of high grades of all the breeds named has 

 essentially the same peculiarities as that of the breeds in 

 the pure form, but probably they do not possess these in 

 the same degree. It would seem to be true that changing 

 the quality of the milk produced is not so easily or quickly 

 accomplished as changing the animal form. 



Lactation and milk production. With reference to 

 milk giving it may be said : ( I ) That the period of the 

 lactation exercises an important influence on production; 

 (2) the milk yield is greatest a short time subsequently to 

 the time of calving; (3) after a time it lessens gradually 

 under normal conditions, until finally it ceases; (4) it is, of 

 course, chiefly dependent on the food fed, but not entirely 

 so. 



Milk giving is dependent on maternity, first with refer- 

 ence to its possibility, and second, with reference to its re- 

 newal. The instances are exceedingly rare though not en- 

 tirely unknown, in which cows can be made to produce 

 milk, in the absence of maternity. It is a provision arranged- 

 for by nature, whereby suitable food is prepared by the 

 cow for her progeny to sustain it from birth until it is old 

 enough to live upon other food. In cows left to the in- 

 fluences of nature only, it ceases entirely as soon as the 

 calf is able to provide otherwise for itself, but, subject to 

 man's control, it may be prolonged indefinitely within cer- 

 tain limits. Beyond these, no power or skill can prolong 

 its continuance, hence the necessity for renewal from time 

 to time through the production of progeny. Such renewal 

 is customary with the cow, under normal conditions, about 

 once a year, but frequently it occurs at irregular periods, 

 owing to various causes. 



