I've raised geese for 20 years and simply fed them out of a bucket until two years ago. Then, rats invaded the yard, attracted by the goose feed and the birdseed I had started putting out. There were so many you actually could see them running around the yard in the daytime. Big freak-out.
My vet told me if I stopped feeding the yard birds (it was summer, and I slowly weaned them off the seed) and got a covered goose feeder, the rats would run out of motivation to stick around and would take off of their own accord. That is exactly what happened when I followed his advice. No more rats!
The covered goose feeder I now use I found online. I found it at a site called "Grandpa's Feeders." There's a little treadle that the goose steps on, which opens the lid to the feeder. When the goose walks away, the lid closes. I had to have my handyman make a slight alteration in the feeder to accommodate the shape of a goose, because the feeders are made for chickens. But the geese learned to use them quickly, and they work great. They have the side benefit of keeping the feed dry even on rainy days. The slugs like to get into them, though. Ugh. But better slugs than rats.
My feeder cost $250 or something like that. On the website, there's a video that shows how they work. The lady there, if you phone her, can talk about the modification they suggest you make for geese. I think it was just that we made the treadle stick out a little further. You do have to be careful if you have goslings, though. They could get crushed under the treadle if they're little enough. We put the feeder away when there are tiny goslings and go back to the old bucket system. Other than that, the feeder works fine.