Genetic studies in poultry

Summary

• 1. F ₁ birds from a cross between a white egg laying and a dark egg laying strain lay eggs of an intermediate tint.

• 2. Segregation occurs in theF ₂ generation, the two parental grades, together with all intermediate ones being found.

• 3. There is evidence for the existence of an inhibitor of pigmentation in one of the whiteegg strains used, and there is some evidence for regarding this inhibitor as being associated with the factor for black plumage.

• 4. Broodiness is a highly complex character. F₁ hens are generally broody. The proportion of broody to non-broody birds in F₂ varies greatly in different crosses.

• 5. The factors for broodiness and for egg-colour are transmitted by the cock as well as by the hen.

• 6. Though there is slight evidence of some association between the brown egg and, the broody habit, the two characters may be dissociated. It is clearly possible to establish a non-broody strain laying brown eggs.