nant white line, while the importance of extended black is questioned. Fur- 

 ther data is needed to determine the effect of barring on red, particularly 

 when in combination with silver. 



F. L. Cherms, Jr., W. M. Collins 



Growth Rate of Durham X New Hampshire Crosses 



Three years' results of crossing Durhams with New Hampshires indi- 

 cates that the crosses grow much more rapidly than pure Durhams and at 

 about the same rate as the Experiment Station New Hampshires. In the 

 1953 and 1954 New Hampshire 4-H Chicken-of-Tomorrow contests, the 

 growth of Durham crosses compared quite favorably with the growth of 

 several good commercial broiler strains. Crosses of Durhams with the Ex- 

 periment Station New Hampshires usually have greater breast width than 

 the pure New Hampshires. 



Improvement in growth rate within the Durham breed has resulted 

 over the past three years by selecting on a closed flock basis. It is planned 

 to compare the efficiency of the closed flock system with a newer breeding 

 method in selecting for combinability for growth rate and other characters 

 of economic importance. 



W. M. Collins, F. L. Cherms, Jr. 



Breeds and Strains of Chickens Differ in Amount of Yellow 

 Pigment Present in the Shanks during the Growing Period 



It has been known for some time that relatively minor changes in the 

 content of a poultry ration may influence the degree of shank pigmentation 

 in chickens, and such modifications frequently result in changes in the effic- 

 iency of the ration. Certain diseases, such as coccidiosis, often effect changes 

 in the color of the shanks to the extent that chickens with pale shanks are 

 often discriminated against by the buyer of live poultry. 



Breed, strain, and sex differences in shank pigmentation were observed 

 in a study involving chickens entered in three trials of the 1953 New Hamp- 

 shire Broiler Test. The study showed that the shanks of New Hampshires 

 were more deeply pigmented than the shanks of White Plymouth Rocks and 

 that certain strains within each breed differed significantly in shank color. 

 It was also observed that the shank color of males was significantly darker 

 than the shank color of females. 



In each breed studied, the within-strain variation in shank color ap- 

 peared to be sufficiently large to enable the interested breeder to successfully 

 select for improvement in this character. 



W. M. Collins, S. C. Thayer 



Selection of Poultry for Better Feed Utilization Efficiency 



For the past two years the feed consumption for maintenance of indi- 

 vidual adult males has been measured over a short feeding period. Feed 

 consumption of individual females similar in weight and producing at about 

 the same rate has been measured during a period of comparable length. Se- 

 lected males and females have been mated, and growth and feed consump- 

 tion data taken on the offspring, so as to develop two lines of chickens, each 

 differing in feed utilization efficiency for growth. 



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