Breeding poultry is no different than that of any other animal whether it is a dog, cat, cattle, horses etc. For me the most important advice I can give is bypass all the less than desirable online information that simply makes you feel better about your own flock because others feel the same way & look at your flock without bias. Once you overcome this, key on information from experts who are critical of the breed. For me it is the Ayam Cemani Breeders Association’s “Standard of Perfection”. Only then will you notice improvements in your breeding stock.
https://ayamcemani.us/standard-of-perfection/
How? I think a previous member summed it up…by beginning with a good foundation. Something that always makes me chuckle is that famous Cemani Roo on the web from GFF. You know the one…all dressed up in jewels? Look close the next time you view that photo. That Roo is full of mulberry in his wattles, for that matter probably in his comb as well.
I dealt with those same issues for 3 years, almost 4. Thinking I could continue to purchase from the same breeder thinking one day a couple of good ones would magically appear. Don’t full yourself it isn’t going to happen. The fact of the matter is it only gets worse. Why…in-breeding.
Make sure you get plenty of photos from a prospective breeder, close-up photos of the face, underneath the wings, feet, & inside the mouth (grey inside the mouth ok). Look for any signs of off colors; mulberry & pink or off colors in the feathers. If for some reason the breeder hesitates to send specific photos, move on to the next, etc.
Another important factor is recognizing once you’ve established your breeding stock you mustn’t led up. You are still going to need to be critical of the offspring. Continue to monitor for the same less desirable traits mentioned above because although they will occur in much less frequency, they will happen. Cull those from your flock immediately. Just as important; do not forget to mix up your breeding stock over time or you'll be right back where you started.
I am in no way saying this is the correct way to go about it although it is what has worked for me. Good luck & don’t expect success to happen overnight…it takes time.