I feed my hens a few ounces of fishmeal several times a week. I have a cup feeder that they can eat free choice. There is never any left at the end of the day that I give it to them. I have never had a fishy tasting egg. You can supposedly feed 5-10% fishmeal without a fishy taste. Fish meal really helps with extra protein. I suppose bone & meat mill does he same.
I know this is an old post but I thought I would add my two cents. I had a calcium deficiency problem awhile back with soft shells in some of my chickens. I give them oyster shells, free choice, but they don't touch them. I add them to their feed and some get eaten. I crust egg shells up and give them in dishes of other treats. Some get eaten. The best way I've found to get extra calcium into the girls is to feed bone meal (I buy it at the natural food store). I sprinkle it on mealworms, in oatmeal, mixed with bowls of grains and treats they might get. I do this several times each week. Their eggs are now strong and the chickens are all doing great. I don't know about the garden grade bone meal but the human grade costs me $12.99 for a good size jar and last me about 2 months.
Renderers collect animal mortalities, animal and food by-products and waste materials from animal production facilities, slaughter houses, packing plants, supermarkets, butcher shops and restaurants. Renderers use a cooking process to remove moisture and kill harmful bacteria. This allows animal and food waste products to be turned into useful commercial goods, including tallow, protein meals, such as meat and bone meal, and yellow grease for use in animal feeds, fertilizers and industrial applications. Many renderers also service the restaurant industry by removing used cooking oil and reprocessing it into an animal feed ingredient.
All the animal protein "meals" mentioned are good sources of both Vitamins A, B12, and D, as well as Omega 3 Fatty acids, other fats, calcium, and protein. .
Since chickens are just little feathered versions of a T-Rex dinosaur they will do very well thank you eating animal protein.
It never ceases to amaze me that people want their hens to free-range so that they have access to bugs but then they freak out at the thoughts of them eating a mouse, snake, small bird, or USDA inspected raw beef.
BTW don't forget to add blood meal and milk products to your list. All of them will do a chickens' body good.