INBREEDING IN RELATION TO EGG PRODUCTION 273 



would make for less heterosis than existed in 1923, and this may in part explain 

 the high mortahty of 1924, yet cross-breeding as such did not appear to increase 

 vigor as measured by laying house mortality. The fragmentary records would 

 indicate that broodiness was reduced in the check birds but that intensity was 

 lower than in 1923. 



Judging the results of inbreeding by the progeny record leads to the deduction 

 that only group 5 was successful and gave satisfactory egg production. In this 

 group the three daughters recorded are all from hen C 6192 whose sire and dam 

 were full brother and sister. She was mated in 1924 to a son of her single grand- 

 dam. The three daughters in group 5 were all inferior to their dam in fecundity, 

 however. 



In group 7 the daughters were all mediocre producers. The first two were 

 from C 8079 and the last three from C 8333. Both of these dams were early 

 maturing but the first gave only late daughters. These daughters represented 

 line breeding to hen B 699 with a record of 222 eggs. They exhibited no improve- 

 ment over their dams and showed no advantages in line-breeding. 



In general, the inbred birds were satisfactory in weight but the tendency to 

 late sexual maturity appeared. Many of them lacked persistency and nearly all 

 lacked vigor. They did not exhibit marked uniformity in characteristics affecting 

 fecundity. 



Plan of Matings — 1925 



Check group 1 again consisted of four outbred daughters hatched in this group 

 in 1923. These were mated in 1925 to an intensely production-bred male unre- 

 lated to them but a full brother to the male used in this group in 1924. 



Check group 2 still included the original sister C 5465 but she was mated to a 

 male, E 1824, that was inbred to her sire. 



Check group 3 was made up of inbred hen C 4746 again mated to outside 

 male C 75411. A male, C 7984, from the heavy producing strain was also mated 

 to a hybrid pullet, C 7718, coming from mating male C 75411 to an inbred hen. 



Inbred group 4 again included hen C 6127 mated to C 8086. Both of these 

 birds were out of foundation hen C 1124 but were not related on the sire's side. 

 They were half brother and sister. 



Inbred group 5 contained the original sister used in 1924 mated to her son 

 who was inbred to foundation male C 1616. 



Inbred group 6 was made up of two inbred daughters of foundation hen C 1124 

 mated to her son that was also related to his mates on the paternal side. Hen 

 C 1124 was also mated to her son C 8086, the same male as in 1924. 



Inbred group 7 contained hen C 8079 mated to her son E 1592, and three of 

 her daughters mated to their brother. 



