The sex chromosome composition of rooster is ZZ and hen is ZW. The cock with sex reversal in the stalk is actually a hen, and the sex chromosome is still ZW. After mating with a normal hen, the offspring were ZZ: ZW: WW = 1: 2: 1, but WW could not survive under normal circumstances, and the rest were ZZ: ZW = 65438+.

That is, cock: hen = 1: 2.