NON-BROODY AND INTENSE BROODY LINES 



Table 6 — Non-Broody Daughters (Pullet- Year Record) from 

 Different Classes of Dams. 



(Non-Broody Line Only) 



In the nine-year period reported, the seven dams free of broodiness for only the 

 first year gave daughters about 71 per cent of which were non-broody the first 

 year. There was, however, considerable fluctuation in individual years, with a 

 minimum of 38 per cent and a maximum of 90 per cent. The number of dams in 

 this class is very small, but the data do appear to indicate some progress in elimi- 

 nating broodiness by this method of selection. The fact should be stressed in this 

 connection that only one dam of the seven gave an entire family of non-broody 

 daughters. This particular hen (K 917) was kept only untilFebruary 2 of her 

 second laying year, and up to that time she had not gone broody; consequently 

 she may not be correctly classified. 



Twenty dams were free of broodiness for two laying years but exhibited the 

 trait in the third year. Considerable fluctuation is seen from year to year in the 

 percentage of non-broodiness in daughters of these dams, but there was no pro- 

 gressive increase in non-broody daughters as the experiment continued. The 

 detailed records show that nine of these dams gave no broody daughters and that 

 the eleven remaining dams gave varying proportions of broody and non-broody 

 daughters. From the standpoint of eliminating broodiness, this group of dams was 

 greatly superior to the preceding group which was free of broodiness in the pullet 

 year only. 



Twenty-one dams were never observed to be broody in three or more laying 

 years. This group might reasonably be assumed to lack one or both of the broody 

 factors. This group of females, when mated to the same males that were used on 

 the previous two classes of hens, gave a somewhat higher percentage of non- 

 broody daughters. Thirteen of these dams gave no broody daughters, and the 

 remaining eight gave varying proportions of broody and non-broody daughters. 



By F"isher's method, the mean percentages of non-broody daughters from the 

 three classes of dams do not show significant differences. Such a result might be 

 anticipated because of the small numbers involved. 



From the genetic standpoint, however, the data show that the ability to trans- 

 mit non-broodiness increased with deferred broodiness in dams and can be signi- 

 ficantly increased by selection of hens for breeding that have not gone broody in 

 the first three or more laying years. 



