LOL! It’s a mess! We have only done this on a RARE occasion when a sow was sick & only for 2 days until we could foster the piglets onto another sow. Have no intention of ever doing it on a full time basis as that is what the sows are for & if piglets are weak/not thriving then it is survival of the fittest. Might sound cruel but it is reality.
There is a pig dry milk formula supposedly available BUT I have never seen it. Someone once told me she saved a litter with plain yogurt (full fat) & so that is what we use in emergencies. If the piglets have not had colostrum their chance of survival will be thin. Piglets need to be fed every 2 hours & they will scream at you to let you know. There is no sleeping through it! It is WORSE than having a new born baby in the house! LOL! We normally start by syringing it in their mouths as a regular teat is too big for them. They often times need a bath/warm wash afterwords as they are certainly not as cooperative as a calf or lamb would be. You want to move them onto a bowl with milk & grain ASAP so that you are not having to get up every 2 hours but that could take a couple weeks.