ANNUAL REPORT, 1939 91 



2 pullets have died from cannibalism and none from diseases or disorders, 

 and no cockerels have died. In the high mortality line 46 pullets were housed 

 and 47 cockerels were retained, all representing complete families. No losses of 

 pullets or cockerels have occurred to December 1, 1939. 



Genetic Laws Covering the Inheritance of High Fecundity in Domestic Fowl 



(F. A. Hays and Ruby Sanborn.) Major objectives in this project are: (1) 

 developing a line that is genetically pure for sexual maturity at 180 to 215 days, 

 (2) fixing high intensity so that the winter clutch size will exceed 3, (3) eliminating 

 all inherited winter pause, (4) eliminating the broody instinct, and (5) fixing 

 genetically high persistency. In addition to the above characters, studies are also 

 being made on fertility, hatchability, chick feathering, body weight, egg weight, 

 plumage color, comb type, shank feathering, and inherited factors affecting 

 mortality rate. 



Mortality rate in the laying house was higher in the 1938 flock than in the 

 three previous flocks, largely because of the paralysis complex of diseases. Special 

 selective breeding to avoid the paralysis complex was used to produce the flock 

 hatched in 1939. Up to DecembCi' 1, 1939, no paralysis has occurred in this 

 generation. 



Experimental crosses with outside stock are being made to check the genetic 

 behavior of characters being studied. The experimental line started in 1913 is 

 also being maintained. 



During the year. Bulletins 359 and 365 have been published on this project, 

 and Bulletin 307 has been enlarged and revised. 



A Study of Fertility Cycles in Males. (F. A. Hays.) This project began in the 

 late summer of 1939. Material is now being collected for studying the stages of 

 spermatogenesis in males of various ages through the winter season. 



Physiological Relationships Between Molting Behavior and Fecundity 

 Characters. (F. A. Hays.) Biweekly observations on the molting behavior 

 of a group of exhibition and production Rhode Island Red males and females 

 was begun July 27, 1939. These and previous observations will serve as a guide 

 to the first breeding phase to be undertaken in the spring of 1940. 



The Technique of Testing Vitamin D Carriers with Chicks. (A. O. A. C. 



method). (R. T. Parkhurst.) Tests are being made of the vitamin D potency 

 of various cod liver oils, sardine oils, fortified cod liver oils, and fortified sardine 

 oils in cooperation with the Feed Control Service and the Nutrition Laboratory. 

 Future work will include other types of carriers. A real need for authentic in- 

 formation regarding claimed potencies is indicated. 



SEED CONTROL SERVICE 

 Philip H. Smith in Charge 



Seed Inspection. (F. A. McLaughlin and Jessie L. Anderson.) From December 

 1, 1938, to December 1, 1939, the Seed Laboratory received and worked 2663 

 samples of seed, of which 1003 were collected by the State Commissioner of 

 Agriculture and 1661 were sent in by seedsmen, farmers, and various state in- 

 stitutions. An additional lot of 224 samples of flower seeds, for field tests only, 

 was also received from the State Commissioner of Agriculture. 



Classification of these samples with the total number of laboratory tests in- 

 volved is shown in the following summary. It will be noted that the total number 

 of tests required for the 2663 samples was 3763; 857 for purity and 2906 for 

 germination. 



