480 



JOHN W. GOWEN 



system, had an average egg production of 62.7 eggs, or, the homozygous pro- 

 duction was 10.9 eggs less than the inbred. The differences of the different 

 inbred-homozygous comparisons range from —22.0 to +10.6 eggs. In nine- 

 teen comparisons the inbred races produce more than the homozygous. In 

 five instances the homozygous races yield more than the inbred. Of the nine- 

 teen trials in which the homozygous races had less production than the in- 



TABLE 29.2 



Vx\RIANCE ANALYSIS FOR PROGENY OF IN- 

 BRED (BROTHER BY SISTER) AND OUT- 

 CROSS (LEADING TO HOMOZYGOSIS) MAT- 

 ING SYSTEMS 



breds, there are four differences which are highly significant and three differ- 

 ences that are in the significant range when account is taken of chance varia- 

 tions. In no instance was the homozygous egg yield significantly larger than 

 that of the inbreds. The data were consistent in showing the homozygous 

 poorer in egg production than the inbred, even though the particular homo- 

 zygous is only a sample of the germ plasm of the highly inbred strain. 



The average difference between the homozygous and inbred progeny is 

 — 8.38. Considering each observation as equivalent, the probability that the 

 homozygous are on the whole poorer producers than the inbreds is well be- 

 yond the 1 per cent range by the test. 



