You can feed some plain starter, non medicated, however it is too rich for a complete diet. There will be several big problems. Get gras or other greens to them, even it you have to use scissors to cut some weeds or buy veggies from the grocery. don't feed at night, they eat too much, not normal,when the parents are caring for the goslings they do not get food at night. I haven't heard about beet greens, carrot greens, cabbage, spinach, chard, etc, probably some of each is a good thing. Greens give the proper vitamins and not excessive proteins. The wings and legs will grow slower and stronger. Have fun.