4 MASS. EXPERIMENT STATION BULLETIN No. 289 



In general, the degree of relationship increases in successive generations. 

 This method of breeding might be expected to reduce the amount of variability 

 for inherited characters in the later generations. There are no reasons to assume, 

 however, that inbreeding would reduce variability in egg records produced by 

 environmental influences. 



VARIABILITY IN HEREDITARY CHARACTERS 

 AFFECTING FECUNDITY 



The five hereditary (characters — age at sexual maturity, winter intensity, 

 winter pause, broodiness, and persistency — are known to have significant effects 

 on the annual egg records of the flock studied. Results of breeding for three 

 generations from three selected foundations may be studied with respect to varia- 

 bility in the above five characters and in winter and annual egg production. 

 Table 1 records the coefficients of variation of the four generations in this ex- 

 periment with respect to the five inherited characters and for winter and annual 

 egg records. 



The check group is made up of 1695 birds hatched in the five years from 1925 

 to 1929. These birds compose the general flock being developed for high fecunditj^ 

 and are used as checks on all records, except winter production. Flocks hatched 

 from 1916 to 1925 including 3867 birds furnish the check coefficient of variation 

 in winter egg production. 



Table 1 — Coefficients of Vari.\tion in Characters Affecting Fecundity 

 AND IN Winter and Annual Production. 



