Massachusetts 

 Agricultural Experiment Station 



Bulletin No. 242 April, 1928 



Vigor in Production - Bred Flocks 



By F. A. Hays and Ruby Sauibom 



In pedigree breeding for high fecundity, the question of vigor is of 

 paramount importance, because the mortality rate tends to become higher 

 <^ sgg production increases^ In the Rhode Island Red flock studied, 

 vigor was found to be independent of the fecundity traits, early maturity, 

 high intensity, non-pause and high persistency; but to be reduced by 

 eliminating broodiness. The most feasible practice for improving vigor 

 is to breed only from those families showing the lowest mortality of 

 pullets in the laying houses. 



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AGRICULTURAL EXPERLMENT STATION 

 AMHERST, MASS. 



