BREEDING AND TREATMENT OF DAIRY CATTLE. 35 



there can be no doubt of the success of this line of breeding in 

 the object desired, there is the danger of infertility and tuber- 

 culosis if the line be followed very far. 



Purity of Breed. 



But, on the other hand, purity of breed may be maintained 

 without necessarily incurring the danger of developing disease 

 and destroying fertility. Fresh blood repeatedly introduced is 

 necessary in order to avoid the danger spoken of; but it must 

 be blood of the same strain and tribe, if purity of breed is to 

 be preserved. The danger only exists when closely-related 

 animals males and females of the same herd or family inter- 

 breed generation after generation, to the exclusion of outside 

 relations. But in most of our distinct breeds of cattle, and 

 particularly in the Shorthorns, there are many pure-bred herds 

 of one particular strain or other of Booth or Bates blood, for 

 example and these herds can supply to each other all the 

 fresh blood that is necessary to preserve the vigour and sound- 

 ness of cattle. And, indeed, if such fresh blood of the same 

 strain be introduced from other soils and climates, and even 

 other countries rather than from the same neighbourhood, the 

 benefit will or may be all the greater. I am not aware that any 

 great benefit has been derived from the few Shorthorns that 

 have been brought to this country from Canada; the Americans, 

 however, perhaps even more than the Canadians, have found 

 and will continue to find it advisable to repeatedly and con- 

 stantly obtain Shorthorns from Great Britain. But, in any case, 

 it is generally an advantage to get bulls from the Northern 

 Counties down into the Midlands, and from a limestone soil to 

 any other kind on which cattle are kept. In the case of cereals 

 of oats, at all events it is better to fetch them from the 

 north than from the south. Most of our various breeds of 

 cattle have now been bred towards a given model for each 

 breed, wherever any pains at all have been taken. The 

 approved model of a Shorthorn, an Ayrshire, or a Jersey, for 

 instance, is well understood, and all breeders of note have 



