I wouldn't fancy having to try and sleep within a mile of any pigs that hadn't been fed for a couple of days

Maybe other people do it differently, but I usually feed them the night before, just not on the morning of the 'deed' it has the added bonus of making sure they'll follow me and the bucket when we get to the abbetior (not a pig board in sight

) We have had some which broke out of their pen on the morning of going to the abbetior and gorged themselves on apples - I was expecting the abbetior to have something to say about it, but luckily it didn't seem to matter.
Everyone will have their own ideas about what's best - if you're in any doubt I'd suggest a quick phonecall to your abbetior to double check with them.
Hope this helps.