2 month old puppies question?

Like YellowBlackMask said,

Pull the pups out when they are still wanting more.
As they get older let them bay a little longer. Give the command to "break", "back" or "caught hog" or whatever command you use to call the dogs off when taking the pups out of the bay.

The pups will out grow this 20 pounder pretty quick and will probably start catching so you will have to cut back on how many pups are baying and you will have to get a larger pig.

The main reason to want to start with the smaller pig is so that the pups get the confidence early on that they can win and they can stop any hog.

I wouldn't train too often or the pups will burn out. The bay pen is good to teach the young dogs how to bay and stop and keep hog bayed. Once the pups are older and faster you can get in the bay pen and make the hog break so the pups can shut it down. There are other ways but this has worked for me.