I built some 12 x 16 foot hoop houses with internal divisions so my pigs could give birth in a shelter if the wanted to. The hoops are skidable with a tractor, which is useful since rotating where pigs are introduced to life is a good idea. Pigs are born after only about 4 months gestation and the immune system of a small pig is very naive, which make them susceptible to parasitic worms when they're young. Putting the sows on fresh ground right before farrowing is a best practice. Only two out of seven availed themselves of the offered spaces. The rest decided that out-of-doors natural birthing was more to their taste and delivered their litters out under the stars. All of the mothers were first-timers so I gave them a few days to acclimate to the new role and then stole the piglets away and put them in the hoop. Once the babies were safely stowed inside I gently herded the mommas in too. The seven that gave birth all went within two weeks of each other, though I'm still waiting on one more big pregnant gilt. For some unknown reason she did not breed in the same window as the other seven.
Half the reason I wanted hoops was to safely be able to sequester myself away from the mother while I castrated the boys to turn the boars into barrows. Pigs do not like being lifted up and squeals put sows on edge. I didn't relish the thought of holding a baby pig and running for my life from a justifiably angry sow only to trip and end the day with bite marks or worse. With the hoops I blocked the sows out and then could catch the pigs without causing undue stress and angst to anyone.
A few days after castration I let the sows out of their individual pens and to allow them co-parent as one sounder. The piglets show only moderate affinity for their actual mothers. Whenever a sow lies down and grunts for piglets to nurse a whole mixed pile charges in and hammers the milk bar. And I use the word "hammer" advisedly, piglets don't nurse calmly and slowly - think rugby scrum not yoga class.
Unlike a lot of people I don't think baby pigs are incredibly cute in appearance. I award the cutest baby animal ribbon to lambs. But I do think the personality of young pigs is hard to top. They're super curious and watching them bop about and chew on woodchips or grass or nose about in the dirt is entertaining. When they're all piled together sleeping I think the collective mass of babies is more endearing than the snub nosed individual for some odd reason.
Pig terminology in this post in case you are curious -
Gilt - A young female pig that has never given birth. Gilts can be tiny little newborn or several hundred pounds, pregnant and about ready to pop, or anywhere in between.
Sow - A female pig that has given birth.
Boar - A male pig.
Barrow - A castrated male pig. Castration with pigs is necessary to prevent boar taint, which affects some, but not all male pigs. Feeding a pig all the way to market weight and then losing it to taint imposes an insurmountable financial burden on the producer. Castration also reduces aggression between pigs. Since I keep my pigs to an older age than many commercial farms castrating to prevent secondary sexual development is important to me as well.
Sounder - A herd of pigs.