6i4 Bulletin 318 



equal importance to the economical production of eggs. Consequently 

 the consistent advantage shown in Table 39 by the combined strong 

 flocks, relative to fertility and hatching power of the eggs, should receive 

 due consideration. 



The incubation of several thousand eggs from both the strong and 

 weak flocks is sufficient foundation on which to base fairly conclusive 

 evidence. The difference in fertility alone shows an advantage of 6.2 

 per cent in favor of the strong flocks. The difference in percentage of 

 eggs hatched to total number of eggs set favors the strong flocks by 4.5 

 per cent. In other words, for every 1,000 eggs set, 45 more chicks were 

 hatched from the eggs of the strong flocks than from those of the weak 

 flocks. On a basis of 10 cents value for each day-old chick, this would 

 represent a value of $4.50 extra profit from each thousand eggs hatched 

 from the strong flocks. In addition, the same table shows the chicks 

 from the strong flocks to be slightly heavier, and consequently more fit 

 to begin growth. This fact is illustrated in the table by the percentage of 

 chickens alive at the end of six weeks. 



It would seem from these composite tables, therefore, that the con- 

 stitutionally strong fowls, even though the degree of superior strength 

 is but small (as stated on pages 573 to 576), are capable of producing a 

 larger number of eggs with greater economy, more fertile and hatchable 

 eggs, and stronger progeny. 



CONCLUSIONS 



1. The selection of fowls for strong vitality, even though the selection 

 be slight and exercised but once, increases the productive and the re- 

 productive power of a flock. 



2. One selection only, no matter how rigid, is not sufficient to keep 

 a flock permanently superior. 



3. The selection of mature pullets is of more value than that of partly 

 grown chickens. 



4. Selection at the beginning of the second year is of equal importance 

 to that of the first year. 



