[pig-in-paradise]

I have a probably stupid question regarding the portion size of the fruits/veggies we're not supposed to feed daily.

Apples, for example, are a 1-2 times a week food, but how much? If I were to give a quarter of an apple per pig, I'm sure that would be too much. But how much is one portion?

How about grapes? Is one portion just 1 grape, or is it more?

It just doesn't make sense to me to limit the times per week the food can be given if I don't know the portion size.