The short leg gene breeds out quickly.I cross my extra Ayam Cemani roosters with meat birds. I have hatched out 5 of them between 7 and 9 weeks old now. I am expecting them to mature around 16 weeks since its about halfway between the Mothers early age of maturity and the fathers later age of maturity.
I am considering letting a Cemani Rooster breed with a Grey Japanese Bantam Hen. I think that might make a decent little Semi Bantam. Probably keep breeding the offspring back to the Japanese Bantam but I honestly do not like dealing with that short leg creeper gene.
When crossing a black skinned cock over yellow legged hens the result is sex linked offspring. The males won’t have dark skin while the females will have dark skin.I've never tried it myself but was told a black skinned rooster (AC, silkie) crossed to a non black skinned hen will also produce sex linked chicks with the females being black skinned and the males non black skinned.