were due to close linkage with growth rate genes, or to a true pleiotropic 

 effect of the C\,c alleles. 



Social and sexual ])ehavior were studied in Fayoumi fowl in which 

 the alleles for the presence or ahsence of autosomal harring were segre- 

 gating (11, 12). When the two types of hirds were reared intermingled, 

 white females were socially dominant to harred females, hut when 

 reared separately, harred females were dominant to their white counter- 

 parts when intermingled as adults. No consistent differences in mating 

 hehavior were found. The socially dominant group consistently laid 

 more eggs than the suhordinate group. 



Phaeomelanin intensity was studied in feathers of Buff Orpington, 

 New Hampshire and Rhode Island Red chickens (43, 44. 45. 46. 47 I . 

 Phaeomelanin intensity of chick down feathers was correlated with that 

 of post-juvenile feathers (44) . A correlation was also found hetween 

 postjuvenile and adult feathers in females. Correlations were high he- 

 tween postjuvenile and adult feathers in males. Feathers from sex-linked 

 slow feathering (K) females contained more phaeomelanin than those 

 from their rapid feathering (A- ■") sihs. A series of appropriate matings 

 demonstrated that phaeomelanin intensity was a quantitatively inherited 

 trait. No evidence for sex-linkage was found. Tlie })haeomclanin was 

 fractionated into three parts, hrown. purple I and purple II. All tlirec 

 fractions were shown to he genetically controlled. 



Shank Pigmentation 



Yellow shank color ohservations were recorded at the New Hamp- 

 shire Agricultural Experiment Station (39). Scores ranged from 1 

 (lightly pigmented) to 5 (deeply pigmented) on 10 week old hirds. The 

 experimental hirds were progeny of a cross of dominant white meat 

 type males mated to Columhian patterned meat type females. 



Shank color score ranged from 2.1 to 3.7 among males and from 

 1.2 to 3.3 among females. The data suggested the existence of real sire 

 differences for shank color, and sex-linked genes seemed to he involved. 

 Heritahility of this trait estimated from the sire component was 0.53 

 averaged for l)oth sexes while the sire plus dam components averaged 

 0.41. 



In another experiment at the New Hampshire Station shank color 

 scores were taken at 8 weeks of age from two meat type lines (61). 

 Average color scores of males from the 2 lines ranged from 1.6 to 2.4 

 in l)oth 1960 and 1961. In females the scores ranged from 1.4 to 1.9. 

 Heritahility estimates among male progeny were 0.21 from the sire com- 

 ponent and 0.69 from the dam component. Among female progeny the 

 estimates were 0.16 and 0.23, respectively. The genetic correlations be- 

 tween shank pigmentation and body weight at 8 weeks of age were con- 

 sistently negative. 



Thyroid Activity 



Several techniques for measuring the thyroid activity of chickens 

 were studied at the Delaware Agricultural Experiment Station. The ob- 

 jective was to find a reliable index of thyroid activity for a variety of 

 physiological and genetic studies with domestic fowl. A good measure 



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