Nosing behavior in piglets

Question
Hello, I am searching for someone who can help me with my micro mini pigs.  I purchased them from an online breeder.  I am having an issue with my pigs (3 micro mini males, all biological brothers, born 11/7/12).  The biggest piglet and the smallest piglet gang up on the middle sized one, and "nose" him all day long.  They push him around their play pen, even throw him right up against the bars of the gate and against the wall, even picking him up in the air sometimes.  Sometimes he just puts up with it, sometimes he cries.  His belly is all red from the constant rubbing.  I have done some research on this and found out that this behavior is most often exhibited in piglets that were weaned too early.  It's just very hard for me as a "mother" to watch one of my babies get bullied and hurt.  I emailed the breeder and she was of little help, only saying that it's normal and that I can separate him.  Well the pigs have their own room in our house, but it doesn't seem practical to separate them.  Then he would be all alone.  I have read that pigs love companionship from other pigs, so I don't know if being alone is worse than being bullied.  I am reaching out to anyone who can help me with this.  We have tried disciplining the two bullies.  I have tried yelling, clapping my hands, saying "NO" and tapping their nose, and putting them in "time out" (the bathroom for 5 minutes).  Is there any advice you can give me?  Have you seen this behavior?  Will it ever stop?  We are animal lovers, and would never put our pigs up for adoption, so we desperately need a solution.  Any advice would be GREATLY appreciated.  Also, do these pigs need to see a vet?  Thank you!

Answer
Yes, they are exhibiting natural behavior. Pigs see the world as a ladder, with each person, pet and pig having his or her own rung. The middle pig is obviously on the lowest rung.

The nosing behavior tends to disappear around 12 weeks of age, sometimes later in piglets weaned early. Putting a little Vasoline or lotion on the middle pigs belly will make it slippery and harder for them to hurt him.

If the middle pig is being seriously hurt, then it will be necessary to separate him. Giving them a bigger area, with a couple of "safe" spaces, might help until this stops on it's own.