TIME TO STANDARD EGG WEIGHT 11 



10. The multiple correlation coefficient shows that about 58 per cent of the 

 variation in time to standard egg weight was due to variation in the following 

 seven variables: hatching date, age at first egg, weight at first egg, winter clutch 

 size, winter pause, broodiness and persistency. 



, 11. Probably about 42 percent of the variation in the time interval to standard 

 egg weight was due to unknown hereditary factors. 



12. The birds failing to reach standard egg weight were handicapped by lack 

 of body weight, extremely high intensity, intense broodiness, and lack of persis- 

 tency. 



13. In breeding practice to increase egg size, it seems advisable to select 

 breeding females exclusively from those which attain standard weight egg in 

 less than 75 days after the first pullet egg. 



REFERENCES 



Hays, F. A. 1927. The inheritance of persistency and its relation to fecundity. 



Proc. World's Poultry Congress, pp. 92-95. 

 Hays, F. A. 1930a. Increase in egg weight during the pullet laying year. 



Proc. Poultry Sci. Assoc, pp. 16-19. 

 Hays, F. A. 1930b. Linkage relations between genes for egg size and genes 

 « concerned in high fecundity in the domestic fowl. Proc. Fourth World's 



Poultry Congress, Sec. A, pp. 134-138. 

 Hays, F. A. 1933a. Relation between body weight and age at sexual maturity. 



Poultry Sci. 12:23-25. 

 Hays, F. A. 1933b. Characteristics of non-broody and intense broody lines 



of Rhode Island Reds. Mass. Agr. Expt. Sta. Bui. 301. 

 Wallace, H. A., and G. W. Snedecor. 1931. Correlation and machine calcula- 

 tion, p. 63. Iowa State College, Ames, Iowa. 

 Waters, N. F. 1931. Inheritance of body weight in domestic fowl. R. I. Agr. 



Expt. Sta. Bui. 228. 



Publication of this Document Approved by Commission on Administration and Finance 

 3 M-10-'34. No. 2689. 



