liROOniNKSS AND KKCUNDIT^ JN FOWL 



07 



Coefficient of correlation -\- .2925 



.0297 



A significant coefficient of correlation between l)roodiness and liigli winter 

 rate sugijests tliat there is linkage between broodiness and high winter in- 

 tensity. Fiirtiier evidence lias already been presented in sections H and 9. 

 Herein lies the probalile snperiority of broody breeds over non-broody breeds 

 in winter intensity- 



JJ. Correlation Between Times Broody and Annual Rate — Pullet Year. 



Tiie nictiiod used in calcvdating annual rate does not allow for winter pause 

 or for time lost while broody. It is simply a figure intended to measure the 

 actual rate of laying between the time of laying the first pullet egg, and time 

 of laying the last egg before the complete molt. Winter pause birds and 

 broody birds are actually penalized in calculating annual rate. If there is 

 absolute independence between broodiness and winter pause, the only normal 

 liandicap that the broody bird carries over the non-broody is the production 

 loss during broody periods. Inasnmch as the magnitude of the annual rate 

 depends most largely upon yearly egg production, this method of measuring 

 rate should Vie most significant in breeding for fecundity. It is believed that 

 this is a true measure of actual rate of laying during the year. Constants 

 calcidated from the 2245 individuals studied follow: — 



Xuiniier of l)irds 



Mean times liroody 



Times liroody standard deviation 



Moan annual rate . 



Annual rate standard deviation 



Coefficient of correlation 



221.5 



\A\- 



±1.98 



56.48 



±9.85 



—.2620 ± .ni;J3 



The above constants show that tiie 2245 birds actually laid on 56.48 ]ier 

 cent of tlie possible days between their first egg and the time they ended 

 their year with the complete molt. Tlie standard deviation agrees closely with 

 that for the winter rate. A mean rate of such a magnitude inuuediately 

 suggests high annual production. 



The coefficient of correlation between times broody and annual rate is nega- 

 tive; and its magnitude, together with its small probable error, suggests that 

 liroodiness and low rate tend to move together. 



15v tlie use of the regression coefficient we find that those l)irds with a 

 mean rate of 60.48 will be less broody than the mean of all birds stirtlied 



n 44 .21 = 1.23). The fact is very evident, therefore, that broodiness tends 



to lower annual rate of laying. The coefficient as determined, however, does 

 not represent the true correlation, since the flock of 2245 liirds is made up of 

 both broodv and non-broody races. 



