INTENSITY IN RHODE ISLAND REDS 11 



The data indicate in general that the rate of laying as measured by mean clutch 

 size from first egg to March 1 is a satisfactory criterion of rate of laying through- 

 out the year, and are in agreement with those of Lerner and Taylor (1937), who 

 show that winter rate, spring rate, and summer rate are all correlated with each 

 other. 



Summary 



This report includes the fii^st-year records of 1470 predigreed Rhode Island 

 Red females bred for high fecundity and hatched over a six-year period from 

 1937 to 1942. Particular attention is given to the relation of intensity or rate of 

 laying to egg weight and egg production during the first laying year. 



Some of the more important deductions from this study follow: 



1 . Age at first egg showed very little correlation with egg weight during 

 Tvlarch, either in an extremely early maturing group or in a medium early matur- 

 ing group. 



2. There was a small but significant negative correlation between age at 

 first egg and mean winter clutch size. 



3. Winter clutch size (to March 1) showed a small but significant negative 

 correlation with egg weight to January 1, and a moderate negative correlation 

 with March egg weight, but no correlation with annual egg weight. 



4. There was a negative correlation between winter egg production (to 

 March 1) and winter egg weight (to January 1), and a small negative correlation 

 between winter egg production and March egg weight; but winter egg production 

 and annual egg weight were independent of each other. 



5. The use of the correlation ratio showed that annual egg weight was posi- 

 tively correlated with annual egg production. 



6. Winter egg production showed a significant positive correlation with egg 

 production for the remainder of the year. 



7. Winter clutch size was intimately correlated with annual production. 



8. There was some evidence of inheritance of winter clutch size between 

 mothers and daughters. 



9. Winter clutch size was significantly greater in broody than in non-broody 

 individuals. 



10. Winter clutch size was significantly correlated with spring, summer, and 

 fall clutch size. 



11. These data furnished rather substantial evidence that winter clutch size 

 is one of the more reliable measures of intensity and that it is one of the most 

 important characters associated with egg production. 



References 



Atwood, Horace. 1923. Certain correlations in the weight and number of eggs 

 and the weight of fowls. W. Va. Agr. Expt. Sta. Bui. 182. 



Atwood, Horace. 1928. Certain normal characteristics of White Leghorn fe- 

 males. W. Va. Agr. Expt. Sta. Bui. 220. 



Dryden, James. 1921. Egg laying characteristics of the hen. Oreg. Agr. Expt. 

 Sta. Bui. 180. 



