portion size

Hello everyone, I'm new to the forum and have a question about feeding fresh fruit and vegetables. What is the right amount in a day, and can you overfeed a guinea pig? I know it's not possible to overdose on vitamin C and shouldn't feed sugary foods like apples and carrots too regularly, but...

I know you shouldn’t let pigs eat too much grass at first. But how much is too much? For example, yesterday I gave them about a fistful altogether. Is that an ok amount to start them on? They wolfed it down fast but I didn’t want to give them more in case they got the runs...

That is the amount I give the boys twice a day. Is that enough do you think? Other question is I read they should only get 1-2 sprigs of coriander...is 4 sprigs x twice daily too much then? They do love it. About once or twice they have wheeked (loudly) when they've already had their...