I'm no expert , but I do my research . When you see ground chicken or turkey in store , unless it says " 100 % white meat " ( breast meat ) the fat content can be higher than a lean ground beef .
Keeping a long story short ,
I saved all my chicken trim , white meat plus some fat .
Peeled skin off some thighs and saved it .
Used boneless chicken breast .
I have a pork recipe for Italian sausage , that came out " ok "
Used the recipe with all white meat chicken , some skin , went heavy on the spice , but backed off the salt .
I did not use any powder binders , but did add a good Olive oil .
It was so good , the texture , taste , color ,,, I got lucky I guess .
Many of the UK sausages contain ground up rusk (A rusk is a hard, dry biscuit or a twice-baked bread.) to help improve moisture, soften the texture and to reduce cost. They also add a good bit of water/liquid to the mix. I would prefer something like that to chemical additives.