56 MASS. EXPERIMENT STATION BULLETIN 305 



Naturalist 67: 539-548, 1933; "Characteristics of Non-Broody and Intense 

 Broody Lines of Rhode Island Reds," Bulletin 30L 



A Genetic Study of Rhode Island Red Color. (F. A. Hays.) In 1929 a line 

 of highest quality exhibition Rhode Island Reds was obtained. In 1930 a cross 

 was made using an exhibition male on production-bred females from the station 

 flock. In 1931 reciprocal crosses were made together with F^ x Fj and Fj x 

 original parents. In 1932 the Fg generation was produced and F, birds have 

 been backcrossed to grandparental stock. Complete egg records have been 

 kept on all females along with records of plumage color. The data are now being 

 prepared for publication. 



Determination of Genetic Laws Governing Results of Inbreeding. (F. A. 



Hays.) The fifth generation of inbred progeny was hatched in 1933 from the 

 two remaining lines. Progeny have also been produced by crossing the two 

 lines. Special attention is being given to the prepotency of inbred birds compared 

 with the general flock bred for high fecundity. 



Factors Affecting Egg Weight and Shell Character in Domestic Fowl. (F. A. 



Hays.) Three lines produced each year b\' females laying 52-, 57-, and 59-gram 

 eggs, respectively, during December haxe been carried into the sixth generation. 

 The last two generations (1932 and 1933) have come from females having the 

 ability to lay 52-, 57-, and 59-gram eggs in November of the pullet year. Distinc- 

 tive t^pes of shell color and shell texture have appeared together with significant 

 differences in egg weight when the three lines are reproduced >ear after year by 

 mating the three lines of females to full brothers. 



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

 studies on rate of feathering in Rhode Island Red chicks were made in 1931, 

 1932, and 1933. In the spring of 1933, 3200 chicks were classified for feathering 

 on the twelfth da>- and again at eight or nine weeks of age. Some evidence has 

 been secured that autosomal genes may be concerned in rate of feathering in 

 Rhode Island Reds along with a major sex-linked recessive for early feathering. 



DEPARTMENT OF VETERINARY SCIENCE 



J. B. Lentz in Charge 



Poultry Disease Elimination Law. (H. Van Roekel, K. L. Bullis, O. S. Flint, 

 D. M. Yegian, and Miriam K. Clarke.) During the 1932-33 pullorum disease 

 testing season, 301,000 blood samples were tested by the macroscopic tube 

 agglutination method. This number represented 300,714 chickens and 286 

 fowl other than chickens in 338 flocks. Among the samples from chickens, 

 0.47 per cent were positive, the lowest percentage ever attained in this State. 

 All of the flocks in two counties were classified as negative. In nine of the 

 thirteen counties less than 1 per cent of positive tests were recorded. The 

 number of non-reacting flocks was 276, approximately 82 per cent of the total 

 flocks tested. Of these, 145 flocks were 100 per cent tested. These represent 

 145,420 birds, 48 per cent of the total number of birds tested. No reactors were 

 detected among the turkeys, pheasants, ducks, geese, and guinea fowl which were 

 tested on 12 farms. Chickens were tested on 9 of these farms and revealed 

 infection in 5. Necropsies were performed on 70 birds for 40 flock owners. 



