8 MASS. EXPERIMENT STATION BULLETIN No. 288 



SUMMARY 



Light and dark-colored lines of Rhode Island Reds were carried through four 

 generations to discover possible relations between intensity of laying and degree 

 of feather pigmentation. 



Age at sexual maturity was slightly greater in the dark line. 



Winter clutch size was smaller in the dark line in all generations. 



The gene for smut appears to be independent of the genes for high winter 

 intensity. 



The data show indirectly that deep plumage color occurs generally in slow- 

 maturing birds and that a developmental period greater than 215 days from 

 hatching to sexual maturity is required for the development of the deep shade 

 of pigment now demanded in exhibition Rhode Island Reds. 



There is evidence that a medium shade of red is often accompanied by high 

 winter intensity. 



Overlapping in shade of color frequently occurred between the darker indi- 

 viduals of the light line and the hghter individuals of the dark line. 



Annual egg production was not significantly different in the two lines in any 

 generation. 



Results of this experiment indicate that a medium shade of red is more typical 

 of a Rhode Island Red flock bred for high fecundity than a very dark or a very 

 light shade. 



REFERENCES 



Hays, F. A., and Ruby Sanborn. 1927. Net correlations of characters con- 

 cerned in fecundity. Mass. Agr. Expt. Sta. Tech. Bui. 12. 



Martin, J. Holmes. 1929. Rate of feather growth in Barred Plymouth Rock 

 chicks. Poultry Sci. 8:167-183. 



Ridgeway, Robert. 1912. Color standards and color nomenclature. Washing 

 ton, D. C. 



American Standard of Perfection. 1930. Amer. Poultry Assoc. 



Publication of this DocuME^^■ Approved by Commission on Administration and Finance 

 3M 10- '32 No. 6703 



