52 AMERICAN POULTRY ASSOCIATION 



guard against disappointment by also mating males of the orig- 

 inal line to the females that are one-half new blood, by also 

 maintaining the original line, or by both methods of safeguard- 

 ing the merits of the original line. 



A method commonly practiced, but not commonly enough, 

 which is the safest from two standpoints, is to secure each year 

 or every second year, a female from another strain, mate her 

 with a male of the strain which needs, or may need, an infusion 

 of new blood, and mate the female progeny with the sire or a 

 male of the same line or same breeding as the sire. Both the 

 males and females of this generation will usually have acquired 

 the characteristics of the original strain to a marked degree and 

 breeders may be thereafter selected by the same process as 

 though the blood was of one strain. 



Strain-building. A breeder often desires to acquire, perhaps, 

 a single characteristic, perhaps more than one, in which his strain 

 is deficient. In order to do this, he is compelled to secure new 

 blood from a strain that is noted for the predominance of the 

 required characteristics. This may be accomplished in the ways 

 that have already been indicated, accompanied by accurate selec- 

 tion for those characteristics. If the acquisition of several char- 

 acteristics is desired, because a strain is notably deficient in these 

 respects, the project becomes complicated, and it may be neces- 

 sary to line-breed from the best representatives of one, two, or 

 more strains. 



Line-Breeding. Among poultrymen line-breeding may mean 

 at least one of two things. It may mean, as above, the inter- 

 breeding of two or more strains with all the blood tracing back 

 to a few specimens, usually of extraordinary merit, or predomi- 

 nating in the desired characteristics. The object is to amalga- 

 mate, eventually, the blood of all the strains employed until by 

 perpetuating the desired characteristics, a new strain becomes 

 established. 



The term line-breeding is also used to refer to in-breeding, 

 as when the sire is bred to his female progeny, the dam to her 

 male progeny, or the offspring are bred together, and in-breeding 

 among the progeny is continued, so that the blood of one or more 

 birds reoccurs often in the ancestry of successive generations. 

 That is, when by in-breeding or by in-and-in-breeding, a line is 

 established based upon predominating excellencies of one or at 

 the most two birds, the desirable qualities of which are thereby 

 very strongly fixed in the progeny, it is line-breeding with the 

 number of the breeding lines that are traceable back to the bird 



