BGJD's (Blue Gene Jack Dempsey) are the offspring of a Blue Dempsey and a regular JD. The fry all look like regular JD's but they carry the Blue Gene.
If you breed BGJDxBGJD, you will get 25% EBJD, 50% BGJD and 25% JD.
If you breed BGJDxEBJD, you get 50% EBJD and 50% BGJD.
Basically, you need at least 1 BGJD to be able to breed EBJD's which is why they are sought after.
If you breed BGJDxBGJD, you will get 25% EBJD, 50% BGJD and 25% JD.
If you breed BGJDxEBJD, you get 50% EBJD and 50% BGJD.
Basically, you need at least 1 BGJD to be able to breed EBJD's which is why they are sought after.