My pigs are five miles away and I visit them twice a day. Mornings they have pellets, bread and whatever else I have, also, overgrown courgettes, windfall apples and pears etc. are strewn around their little field to give them something to forage for during the day. Their water is topped up then and also in the evening when they have more pellets.
They have a large plastic box filled with water that they queue up to sit in on hot days also a wallow that gets filled with water in the mornings. they also get a Jaffa Cake each in the evening, don't tell DEFRA!!)