I'd say it depends on what your feeding, and their stage of life.
I often use soybean meal or whole crushed soybenas as a part of our grain mixes, to increase protein, but we raise quail, ducks, and turkeys, so game birds tend to need a bit higher than a chicken.
I often use wheat (umm.. I'm in Kansas and its available from farmers locally) and corn as additional grains. I don't think of them as fillers, they provide nutrition, or I wouldn't buy them or feed them.
Most of my fowl are also allowed free range time, which kind of ofsets protein needs
I often use soybean meal or whole crushed soybenas as a part of our grain mixes, to increase protein, but we raise quail, ducks, and turkeys, so game birds tend to need a bit higher than a chicken.
I often use wheat (umm.. I'm in Kansas and its available from farmers locally) and corn as additional grains. I don't think of them as fillers, they provide nutrition, or I wouldn't buy them or feed them.
Most of my fowl are also allowed free range time, which kind of ofsets protein needs

