49 



ing date is of far less importance from the winter fecundity standpoint than is 

 age at first egg. There are two possible reasons for this: first, early sexual 

 maturity is associated with high winter fecundity to a greater extent than 

 merely the time element; second, late hatching has already been shown to 

 reduce the age at first egg. 



Weight at 150 Days versus Winter Production. 



In selection of pullets to put into winter quarters or in deciding upon birds 

 to be placed in egg laying contests, the breeder desires to know just how much 

 stress should be laid on physical characters. Weight is one characteristic that 

 can be definitely measured. The weight at 150 days old was secured on 800 

 pullets that later completed winter records. The degree of correlation has 

 been determined between weight at 150 days and winter production. Con- 

 stants calculated are as follows: 



Number of birds .... 



Mean weight at 150 days 



Weight at 150 days standard deviation 



Mean winter production . 



Winter production standard deviation 



Coefficient of correlation 



800 



3.99 



±.54 



44.54 



±23.02 



+ .2758±.0220 



The mean 150-day weight on the 800 pullets is 3.99 pounds with a standard 

 deviation of .54. The mean winter production is 44.54 with a standard devia- 

 tion of 23.02. Weight records show the fluctuations at the age of 150 days to 

 be between 13 and 14 per cent. 



The 800 pullets show a positive correlation coefficient amounting to .2758 

 ±.0220. This may be interpreted that in about one pullet out of four there is 

 direct association between heavy weight at 150 days and a large number of 

 winter eggs. In this particular flock, selection for heavy winter records would 

 be about 28 per cent accurate if made on greatest 150-day weight alone. 



In order to reduce the effect of hatching date on winter egg yield, studies 

 have been made on two hatches, namely, April 15 and 22. This gives a range 

 of but seven days in hatching date, which is practically insignificant. Con- 

 stants calculated on these two hatches follow: 



Number of birds .... 



Mean weight at 150 days 



Weight at 150 days standard deviation 



Mean winter production 



Winter production standard deviation 



Coefficient of correlation . 

 The coefficient of correlation for the two hatches does not differ signifi- 

 cantly from that for the 800 pullets. This is evidence that hatching date had 

 little if any effect upon the relation between 150-day weight and winter 

 fecundity. 



Weight at First Egg versus Winter Production. 



The question: may the weight of a pullet in any particular variety at the 

 time she lays her first egg be associated with high or low winter record? is of 

 interest and importance. Should the breeder who is striving for high winter 

 records select the heaviest pullets at first egg? These questions may be an- 

 swered in general by correlating weight at first egg with winter record. Such 

 studies have been made on 793 pullets with weight records and winter egg 

 records. The calculated constants follow: 



Number of birds 



Mean weight at first egg .... 

 Weight at first egg standard deviation . 

 Mean winter production .... 

 Standard deviation winter production 

 Coefficient of correlation .... 



793 



5.74 



±.73 



44.56 



±23.04 



-.1894±.0231 



