We wean at 8 weeks, I either close them in the hut before daylight, and reverse the trailer up to the hut and load them, or feed them onto the trailer later in the day (not always 100% catch rate!)
When I took over a neglected herd some years ago, I had to park the trailer on the feed face and feed them on the trailer for several days (mom included) untill they were confident enough for me to close them in. This also worked for the wild boar untill we set up the fences and barn for moving and sorting them.