If you eat any animals or fish, take any part you do not eat and give that to the chickens.
You probably do not need to mix it into the feed, just offer it to them when you have it available. So for example, if you butcher one chicken to eat, give the guts to the rest of them.
Maggots and worms...
This is not an exact match, but most of the weight of ingredients could come from your list:
https://www.fertrell.com/livestock-rations
The site sells ingredients for livestock feeds, and they also list recipes.
Those recipes are probably equivalent to the ones used for the chicken food...