Why does my sow eat her baby pigs and what can I do to stop it?

Pigs tend to do that, usually because of malnutrition.
https://en.wikipedia.org/wiki/Savaging

My best guess is to simply take the piglet and try feeding it away from it’s mother, if that is possible.

This article seems to give info about feeding orphan pigs.
http://www.pigpalssanctuary.com/health/baby_pigs.htm

I hope you save and help them. Peace!

Like humans, some animals just have poor mothering instincts. In zoos they try to keep the offspring with the parents, but not infrequently the mothers will reject, spurn, or even try to kill its own progeny and they’re forced to take the newborn away to be hand-reared. The problem with this is the mother’s milk contains a wide array of white blood cells which pass on immunity to many diseases and a hand-reared animal won’t get that benefit, which is why they tend not to do as well.

It’s possible your sow just isn’t a very good mother and you may have no choice but to hand-rear if you want the piglet(s) to survive.

Try this. If it works you have your answer. If it doesn’t you’re not out anything.
http://www.vinegarguys.com/home/benefits-of-acv/acv-for-pigs