How old are the goslings. One thing I've learned in my now almost 3 month journey into geese is to really watch the protein on young goslings. My oldest started to get droopy wings at around 5 weeks, but they corrected themselves. I've been taping up the youngest one's wings for about 6-7 days now, both wings are extremely droopy without support. One is responding nicely, the other one not so much, because it seems to keep slipping out of the sling.
I started them out very briefly, 3-4 days, on gamebird starter, then switched to a Purina all purpose non-medicated starter that was 20%. It said "geese" right on the label. Too much protein, so fighting angel wing now. Next time, I'll go with something lower, perhaps even making my own blend if I have to. I've read several posts on this forum that recommend staying at around 16% protein.
So, if yours are under about 6 weeks, watch the protein and try to give them as much pasture time to graze as possible.
Basically, you should be able to find a duck/goose grower pellet for older goslings, and a maintainer pellet feed for adults. Supplement with as much grazing and green matter as possible, and you can apparently feed grass hay in the winters. I actually bought a bale of hay today to see if they'll like it.