I think I've seen more success with people using CRBs and lion meats for this because of the quantity of lioness they're able to breed this way . I tend to use GMO cows for breedings that are already quite high stakes instead to just try to further the worth of the cubs if I get good ones, for example if I breed a 5k statted Celestial lioness with a bunch of special markings to one of the leaderboard boys, I would use it then in hopes of getting something like a 2 or 3k statted Celestial based mane mute or dwarf or something along those lines . Otherwise, I just sell them to fund other things since they usually get up to about 50 GB a piece before the next time they're available .