Yes, it's from the colostrum.
I have tried putting shavings down but momma pig wouldn't have it. I took them out because she wouldn't go inside to nurse. I have since changed the old blanket with a clean sleeping bag (house is on the edges of blanket so it's tight so babies can't get stuck in the folds or under it). I also bought a stronger heat bulb, a 250w because they weren't warm enough with the other, now they are fine and no longer huddling. Do you think I should take the little girl inside and feed her formula? It just seems like when I go out there to get her to nurse momma isn't ready and is up and about. I know the milk from her mom is the best option but I just found her outside of the house huddling under a piece of blanket, the boys all know how to get back inside and are fine with their mom but I worry that the little girl will get lost again and get too cold/miss her chance to eat. The longest I have left them alone was 4 hours and that was when I came out to only find 3 babies in the house. What do you suggest I do? My heart says to bring her inside as the safest option but at the same time she needs that nutrition from mom.It's just baby poops, from getting rid of the stuff in their guts when in the womb, at least that's what I've always been told.
In a few days of you helping her getting milk, she should be able to do it on her own. Normal to have a smaller one in first litters and in larger litters.
They soon choose their own nipples and always go to that one.
Do they have any hay to hide in? If you notice them piling together or on mom and shivering, they're too cold.