270 MASS. EXPERIMENT STATION BULLETIN 258 



In weight at first egg the check groups excelled the inbred groups and showed 

 the effects of heterosis. All of the inbred birds exhibited satisfactory weight 

 at first egg, however, with the single exception of hen C 1124. 



Winter pause was prevalent in the female breeders used in 1924 as in 1923. 

 One check female, two in inbred group 5 and one in inbred group 7 did not exhibit 

 winter pause. 



Intensity measured by mean winter clutch was not greatly different from the 

 records for 1923. Five of the nine check birds were genetically intense and four 

 lacked intensity. Three of the seven inbred mothers carried high intensity in 

 1924, as compared with three out of four in 1923. Apparently intensity was not 

 holding up in the first generation of inbred daughters. 



In the check groups two broody and four non-broody birds were used in 1924, 

 compared with all non-broody females in 1923. Only one out of six of the inbred 

 mothers of 1924 was broody compared with all broody in 1923. There was there- 

 fore an apparent gain in non-broodiness over 1923. 



Only one female breeder of 1924 lacked genetic high persistency and she was 

 check bird C 7539. All of the breeders of 1923 were highly presistent and the 

 trait seemed to carry on in 1924. 



Annual egg records for all check mothers made during their pullet year were 

 very mediocre with the single exception of C 4746 in group 3. The inbred moth- 

 ers of 1924 were for the most part very good layers, but C 6127 in group 4 and 

 C 8079 in group 7 were both mediocre layers. 



Reference to the 1924 hatching records of these birds indicates that the inbreds 

 were decidedly superior to the checks. The best hatching record was made by 

 C 6127 mated to a rather closely related male. The inferior hatching records of 

 most of the checks must be due to the outside bloodhne introduced. The num- 

 bers of offspring obtained from many of the matings were inadequate for analytical 

 purposes. 



ResiiUs of Matings — 1924 



The sex ratio of surviving chicks from the check group was 115 to 100, while 

 the ratio in the inbred chicks was 82 to 100. This fact would suggest that inbred 

 males were less able to survive in the early struggle for existence than were the 

 check males. The detailed data do not indicate, however, that inbreeding as 

 such actually reduced the sex ratio. 



