I did feed my goslings chopped kale collard greens spinich letuce and celery and other herbs all mixed as well as pulled grassey weeds from my yard. The lady at the farmers market saved her rements for me and I would go there every two days or so and shew gave me this mixed so it was great. The weedy grass I would just pull up a clump or tow nightly, the goslings loved it all. I had one little cotton patch that started to develop angle wing at 6 weeks literally overnight. I took her to an avian vet she said my game bird feed at 20% protien was way to high for goslings but was fine for the adult. She told me the unmedicatyed chicken feed at 8 to 14 was better; but since one bird ahd developed the angle wing, said to start feeing the goslings only what they would have if raised in a field or if they were wild geese. So grass, and the veggie mix from the farmers market ONLY for two weeks cured the angle wing (also I did tape it flat) and now they are all beautiful healthy birds. Again they love the grit on the dirt of the roots of the weedy grass I would toss in. I heard the same thing about spinich but I think cause all the green I was tossing them was a mix, there was also parsley, scallions and other herbs mixed in as well and all fresh from the farmers market, Mine LOVE watermellon too.Geese are the coolest farm animals ever and very smart, I appllaud you for taking the time to learn on here about care, nutrition is a very vital part of teh goslings life. Have fun. BY the way the pic here in my thumbnail are my babies, who arent such babies anymore all imprinted on me and all very healthy.