50 



Mean weight at first egg is 5.74 pounds with a standard deviation of .73. 

 The range of variability in weight is about 13 per cent and is about the same 

 as was found at 150 days. Here is evidence that pullets weighing the most at 

 150 days will in general weigh the most when they lay their first egg even 

 though there is a wide range in age at first egg. 



A negative correlation coefficient of .1894 ±.0231 exists between weight at 

 first egg and winter egg record. There appears to be an association between 

 light weight at first egg and winter fecundity in about 20 per cent of the flock. 

 The coefficient is small but significant and suggests that weight at first egg is 

 of no very great importance in selecting for high winter record, yet there is a 

 tendency for smaller birds to lay more winter eggs than larger birds. 



By tabulating only the first eight hatches the effect of hatching date on 

 weight is somewhat reduced. Records on 529 pullets from the first eight 

 hatches are available for study. The constants calculated on this group are 

 as follows: 



Number of birds 



Mean weight at first egg 



Weight at first egg standai-d deviation . 



Mean winter production ..... 



Winter production standard deviation 



Coefficient of correlation ...... 



With this group of pullets light weight at first egg is associated with high 

 fecundity in about one case out of three. Hatching date thus appears to 

 affect the degree of correlation. 



Weight Increase versus Winter Production. 



Does the rate of daily gain of pullets between the age of 150 days and the 

 time they lay their first egg show any relationship to the number of winter 

 eggs they will lay.^ Can rate of gain in the fall be considered an index to 

 future winter production? Records are available for study on 788 pullets 

 from which the rate of daily gain has been tabulated against number of winter 

 eggs. The following constants appear: 



Number of birds .... 



Mean daily gain .... 



Daily gain standard deviation 

 Mean winter production . 

 Winter production standard deviation 

 Coefficient of correlation . 



.027 lb. 

 ±.00846 

 44.59 

 ±23.03 



+ .2899 ±.0220 



This study shows the mean daily gain to be .027 pound with a standard 

 deviation of .00846 or a range of variation in gain of about 31 per cent. The 

 length of time over which this gain was measured varies directly with the age 

 at first egg. Very early maturing pullets would begin laying in a comparatively 

 few days after their 150-day weight was taken, while late maturing pullets 

 would not begin laying until more than two months after their 150-day weight 

 was secured. The average daily gain over a two-months' period is scarcely 

 comparable with the average daily gain over a two-weeks' period. Yet from 

 the standpoint of age the two are absolutely comparable in that age bears such 

 a vital relationship to winter fecundity. 



The coefficient calculated for this group is positive and amounts to .2899 

 ± .0220. This factor shows that in about one case out of three heavy daily gains 

 between 150 days old and time of first egg are associated with high winter 

 record. Heavy gainers tend to be heavy winter layers to a certain extent. 

 In a previous section we find that the weight at 150 days is fully as reliable 

 a guide to future winter fecundity as is rate of gain from 150 days to time of 

 first egg. 



If we eliminate the genetically late maturing birds we should expect either a 

 higher or lower degree of correlation between weight increase and winter pro- 

 duction than was found for the entire flock depending on whether or not the 



