Yes, that´s the first I´ve read that points to carbs....I´ve read so many different things, probably because people are just hazarding guesses, as there´s not unquestionable cause for it...there seem to be a number of possibilities. Good to get all-round points of view, though.I just wanted to add that I do not think it is protein that causes angel wing, I think it is carbs. Again geese in the wild eat lots of grass and some eat little amphibians and fish - lots of protein.....
Still doesn´t explain the angel-wing here, they all get fed the same, only 3 have it, and they eat grass all day, in between naps and splashes.
And why does it generally affect the left wing?!