For years they use to think high protein was the cause of leg deformity's in growing foals. Foals that where breed for fast growth had the biggest problem but it was how they where feed that triggered it. Normaly a foal would grazy all day on grass. Humans made them eat grain, hay and lush pastures that was not part of there normal diet. It was found that it is insulin that caused the leg deformities not protein. When the glycemic index of the feed and the glycemic load was kept low there is no leg deformities. Corn was high glycemic. Oats where low glycemic. They also found if you could slow digestion there was not these insulin spikes. Some things that slow digestion is larger partical size, acid (vinegar), fats, soluable fiber, and protein,
I think the same type of think is happening with geese. This is one reason I will not free feed my geese anything except greens or produce. When they are small I feed small amounts of waterfowl food, seveal times a day. I am hoping this helps reduce my chance of angel wings. I did have angel wings on one breed of ducks I bought years ago from Sandhill Preservation Center. The other breeds I bought and raised with them had normal wings. In that case I think that breed had a predisposion of getting angel wings do to there fast growth.
