286 POULTRY BREEDING AND MANAGEMENT 



ing or the method of brooding is not always responsible 

 for eggs failing to hatch and for chicks failing to live or 

 grow well. The parent stock, or the condition under which 

 the parent stock is kept, is sometimes to blame. 



Breeding stock, therefore, should be carefully selected, 

 only those individuals being retained that are up to a cer- 

 tain standard of shape, size and vigor. 



It is not claimed here that lack of vigor in the parents 

 will inevitably be transmitted to the offspring. Parents 

 of apparently weak constitution may breed vigorous off- 

 spring. A chicken may have been injured in its rearing 

 and show weakness, without, however, impairing its value 

 as a breeder of strong, healthy stock; but the poultryman 

 cannot afford to retain in his flock fowls showing con- 

 stitutional weakness. Lack of vigor in the parent stock 

 may not always show in the offspring, but it will invariably 

 show itself in smaller egg production and in eggs that do 

 not hatch a high percentage of chicks. There may not be 

 constitutional weakness in the fowls that lay the eggs, but 

 if there is lack of vigor there will be correspondingly few 

 eggs that are fertile and fewer of the fertile eggs that 

 hatch. 



Methods of Hatching Sometimes Responsible for Poor 

 Hatches and for Lack of Vigor in the Chicks. Do not 

 always blame the parent stock for poor hatches and for 

 poor chicks. At the Oregon Station one method of hatch- 

 ing gave an average of 78.8 chicks from a hundred eggs 

 set, while another method gave 60.6 chicks. When brooded 

 in artificial brooders, 90% of the chicks hatched by the 

 first method were alive at the end of four weeks, while 

 only 67% of the others were alive. When brooded under 

 hens, about 98% of those hatched by the first method were 

 alive at the end of four weeks, and only 51% of the others. 



While it is true, therefore, that lack of vigor in the 



