Piggies are rather opportune little creatures - they know how to make you think they need feeding, even just as they've finished eating! The right balance of food is thought to be around:
- 75-80% hay
- 15-20% fresh fruit and veggies
- 5% dry food
As long as they are eating their hay well and they get at least one handful of fresh veggies a day, their diet is usually fair. Often spreading the feeding of fresh fruit and veg over two meals a day works best. The dried food tends to just "round off" the diet and provide any nutrients that might have been missed in the hay and fresh foods.
Don't overfeed dried food, it can lead to unnecessary weight gain in adult pigs; around a handful per pig each day is plenty, you can top up later in the day if you wish to, but don't fill the bowl to the top and let them pig out on it; their hay is far more important!
So if they keep wheeking at you and pestering you to feed them, just top up their hay. My favourite trick is to give them a different type of hay than they're usually fed, as that really satisfies the little monkies and makes them think they are being given special treats!