[Tricky Trev]

we Have 2 OSBs 1 in pig how long can you keep them together for going to try to get other in pig in a couple off  weeks when she comes in season again .

[Beewyched]

I would recommend seperating out at 2 weeks before her "due date". 
If you're worried about them being lonely, could you put them in adjoining paddocks, so they could still see each other but have their own space?
 

[oaklandspigs]

Yes no problem in leaving them together until just before she farrows, we seperate at ten days.
 
In fact if you have more than one ark it is highly likley that when she farrows she'll pick one and the other pig will use the other.  Whilst initially they will stay seperate, there is a slight risk that when they re-unite two large sows sleeping together will squash a piglet, which is why you should generally seperate, and of course if you only have one ark in the area it may be the mum that sleeps/farrows outside which is highly undesirable.
 
 
 
 

[Gary]

All of my sows except for just one like to farrow in peace and quiet and being lonely is never a problem, as for the one she has to be as near to our large white boar as possible dont know why but she has even broke out to be near him!!

[Tricky Trev]

thank you all for info iam saving a paddock with plenty off grass on it so will just split it into 2  couple  of weeks before regards trevor