How old are your sows and how long have you had them? What is their background?
If piggies of any gender get riled up, this carries on and spills over to whoever is close to them. After a fight/failed intro, it always takes quite time for everypig to settle down and reaffirm the existing hierarchy; sometimes a day or even longer, depending on how shaken up the top sow is.
Please be aware that not all piggies of either gender will necessarily get on; sows can be as picky as boars! Very dominant sows will not accept anypig (i.e. another sow or neutered boar) that can threaten or challenge their dominance.
If you can, leave your two girls be or if you are really intent on having a group, think about adding two younger sows that are not able to challenge the existing hierarchy, but have each other to fall back on. A sow quartet constitutes a mini group with dynamics that are a bit different to those of a pair. Trios are the most tricky constellation of all to get right; trying to add a newbie to an existing well bonded couple often fails. Once piggies have made up their minds about somepig, they very rarely change it, so from my own experiences, I wouldn't try again with your new girls and look for other solutions instead.
With small group bonding, it is always advisable to date/meet&greet your piggies at a good rescue to see whether they will gel before you bring them home. With sows, acceptance should ideally happen within 15-30 minutes of first interaction. After that, you move on straight into the dominance phase (the hierarchy sort out).
You may find our information threads at the top of the behaviour section helpful.
With members from all over the world, we are grateful if you added your country, state or (for the UK) your county, as that means that we can tailor our advice and recommendations to your circumstances better right from start. Click on your username on the top bar, then go to personal details/location.
