34 



N. li. Agr. Experiment Station [Bulletin 265 



The average distribution of egg sizes is shown at four different ages 

 in Figure 12. The curve at the lefl illustrates the distribution at 24 

 weeks of age. It will be noted that a greater part of the eggs produced 

 fell below the 20-ounce line and that only a few eggs were over 24 

 ounces. At thirty weeks of age. the entire curve of distribution has 

 moved to the right about 2 1 L > ounces. At forty weeks, the curve is 

 practically the same in shape and range but is to the right of the thirty- 

 week curve by about 2 ounces; and again the fifty-week curve is quite 

 similar except that it is still further to the right. The highest point of 

 the curve of the L'4-week old pullets was 20 ounces; of the 30-week old 

 pullets, 21. and 22 ounces; of the 40-week pullets, 24 ounces; and of the 

 50-week pullets, 26 ounces. 



to 

 o 





z 

 -J 

 o 



i 



12 13 14 15 lb 17 



18 19 20 21 22 23 24 25 26 27 28 29 30 31 



Weight of Eggs - Oz per Doz. 



I'"i< h uk 12 Average egg size distribution of 22 Rhode Island lied pullel 



flocks at four different ages. 



This distribution of eggs by ages has an important bearing on 

 grades. In order to study the effect of size of eggs on gross returns, the 

 distribution for each week was separated into three weight classes: 

 (1) 24 ounces or over, (2) 20 ounces up to 24 ounces, and (3) under 

 20 ounces. This classification is a little stricter than the state grades, 

 but seems the most practical division. 



Distribution of Eggs into Grades by Age of Pullets 



In Red flocks, as shown in Figure b'5, the number of eggs under 20 

 ounces dropped quickly from SO', al 22 weeks of age to about 10$ at 

 30 weeks of age. The proportion of large eggs (over 24 ounces) in- 

 creased from 5% at 22 weeks of age to approximately 80% at 50 weeks 

 of age, after which there was no significant change in weight. At 2!> 

 weeks of age, less than 1.V,' of the eggs were over 24 ounces, an I less 

 than 15$ were under 20 ounces. In other words, at this age the aver- 



