224 PRINCIPLES OF POULTRY BREEDING 



8. What is the relative influence of sire and dam upon trans- 

 mitted characteristics, say in egg production? 



9. To what extent does the condition of parents at the time of 

 service affect the offspring? 



10. To what extent may conditions previous to and during 

 incubation affect the offspring? 



11. What are the advantages and disadvantages of inbreeding, 

 line breeding, and out-crossing? 



12. How can definite and practical results be secured with the 

 least expenditure of time and numbers? 



Upon the answers to many of these problems depend the future 

 methods of poultry breeding. Our information is complete on 

 many points, yet other scientific knowledge is wanting. Much 

 labor is being expended in the solving of these problems; mean- 

 while the breeder must utilize the material at hand as best he may. 

 The summary following in this chapter will, in a general way, cover 

 the present knowledge of the subject. 



Basis of Value in Poultry. The basis of value in poultry keep- 

 ing is the power of the individual to produce a given product at 

 a profit. The relative value of the individual depends upon its 

 adaptation to one or more particular uses and the returns which 

 it yields above the feed consumed. For example, the best laying 

 hen is the one which converts the largest amount of feed into eggs 

 of the best quality with the least possible waste of the feed con- 

 sumed. While a large consumption of feed is necessary to heavy 

 production, it is not in itself a guarantee of heavy production. 

 The mongrel hen is often a heavy consumer of feed; but, owing 

 to the fact that her bodily functions are not developed sufficiently 

 to turn every atom of feed not required for maintenance into eggs, 

 she does not yield a profit. A certain amount of feed is required 

 to maintain the body, and observation proves that the individual 

 which consumes the most feed in proportion to its live weight will, 

 in the majority of cases, be the most profitable; hence the necessity 

 of studying individuals closely, and breeding from those which 

 possess the qualities to be desired in their young. 



The records of a few noted hens show what breeding and selec- 

 tion will do; and also show that in order to increase the productive, 

 or basic, value of poultry, one must study the individuality of his 

 flock, and mate from the very best, with the idea of eliminating 

 the poorer birds and of intensifying in the progeny the desired 

 qualities which are pronounced in the selected parents. 



