Observations on blood plasma postalbumins and hatchability of chickens

In chicken blood plasma two bands have been observed in the region of postalbumins. The genetically determined faster migrating band PasA was present in the blood plasma of all tested males in the plasma of a majority of the females. The slower migrating band (PasB) was only observed in the blood plasma of laying females and never in the blood plasma of males and non-laying females. The genotype of individuals of which the faster migrating band was present was determined as AA and Aa and of those lacking this postalbumin as aa. An excess of females over males was found from mating of male Aa x female Aa and male Aa x female aa. At the same time the percentage of hatched eggs was lowered respectively.