Because they just do better. It's a more varied diet, the birds like whole grains, which are good for them. The high protein of Game Bird has animal protein and fats, which cause the hens to do well. It's just a better all around diet for classier birds. Unfortunately, it is costly. Show people do even more, much more, quite frankly. They need/want their birds to look their very, very best.
But, just before breeding season, I switch them to that diet, and absorb the significantly higher cost of doing so. Hope that helps.
