PRINCIPLES OF LIVESTOCK BREEDING. 47 



METHODS OF SELECTION. 

 GENERAL CONSIDERATIONS. 



In a broad sense the whole subject of practical breeding comes under 

 the head of selection. The considerations which should determine 

 the general policy of mating have been discussed in the previous 

 section. 



In the present section, selection will be considered with respect to 

 the characteristics which it is desired to improve rather than to the 



Fig. 13.— A Lincoln ram, an example of the long-wool type of sheep. The Corriedale breed was 

 developed from crosses of rams of this type with fine-wool ewes. 



system of mating. The most obvious basis for such selection is the 

 performance of the animals themselves. A dairy cow with a record 

 of 1,000 pounds of butterfat in a year is more likely to produce a 

 useful calf than one which produced only 200 pounds under the same 

 circumstances. Unfortunately, the merits of most kinds of livestock 

 can not be measured so directly. The study of conformation as an 

 index of useful qualities has accordingly held a high place as a basis 

 for selection of breeding stock. Livestock judging has this for its 

 purpose. An animal of good stock is a better one to breed than one 

 of equal individual merit but of mixed or common breeding. His 



