ANNUAL REPORT, 1937 89 



3 broody to 1 non-broody. These limited data show typical results from mating 

 individuals that are genetically untested for broody genes. 



The present generation hatched in 1937 was sired by two yearling males with 

 a non-broody heritage, mated to yearling, two-year-old, and three-year-old hens 

 with non-broody records. This generation of 100 daughters will furnish data on 

 the question of deferred broodiness. 



Breeding Poultry for Egg Production. (F. A. Hays and Ruby Sanborn.) 

 Selective breeding has been carried on in an effort to increase the number of 

 eggs laid and at the same time to improve the flock in body weight, in rate of 

 chick feathering, and in plumage color and to eliminate such undesirable charac- 

 ters as small egg size, light egg-shell color, mottled ear lobes and lopped comb. 

 Another major objective has been to reduce variability in annual egg production. 



The last generation of birds shows the general progress that has been made 

 in the experiment. Broodiness stood at the low figure of 4.35 percent of the birds. 

 The mean annual egg production was 234.5. The mean length of winter pause 

 has fallen to 10 days, winter intensity has not changed, persistency has increased 

 from 337 to 351 days — all in comparison with the previous flock. The mortality 

 for a full year in the laying house without culling was 15.95 percent. 



In order to test the mode of inheritance of a number of characters being studied, 

 crosses with outside stocks are constantly being made. The results obtained in 

 this project, however, are measured on the pure strain of Rhode Island Reds that 

 has been carried since 1913. 



Statistical Study of Heredity in Rhode Island Reds. (F. A. Hays and Ruby 

 Sanborn.) Data have been tabulated and prepared on eight years' work on the 

 inheritance of egg size and external shell characters and published as Station 

 Bulletin 344. Data on body weight in relation to egg production characters, 

 factors affecting fertility, and the relation of time interval between clutches and 

 fecundity are in preparation for publication. 



A Genetic Study of Rhode Island Red Color. (F. A. Hays.) Some progress 

 has been made in developing an exhibition line for color alone and another line 

 with exhibition quality combined with the characters essential to high fecundity. 

 Progress is hampered by the necessity of working with small units. 



Rate of Feathering in Rhode Island Reds. (F. A. Hays.) The generation 

 hatched in 1937 showed 37 percent of the males to be early feathered in the rapid 

 feathering line and none to be early feathering in the slow feathered line. The 

 wide family variability in the early feathered line indicates that female breeders 

 should be carefully selected from those families with the highest percentage of 

 early feathered males in order to make rapid progress in fixing early feathering 

 in the flock. No relation between rate of feathering and fecundity characters has 

 been discovered thus far. 



Breeding for Low Mortality. (F. A. Hays.) Two lines are being developed 

 with respect to mortality rate in the laying houses. The sole basis used in selecting 

 is the mortality rate during the first year of laying. The high and low mortality 

 lines have been carried through three complete generations. Mortality rates in the 

 high line were 40.0 percent, 24.2 percent, and 16.7 percent. In the low line the 

 rates through three generations were 39.5 percent, percent, and 10.3 percent. 

 Annual egg production of the survivors was higher in the low line than in the high 

 line for two generations and equal in the two lines in the third generation. Selective 

 breeding appears to have produced a significant difference in the mortality rates 

 of the two lines. 



