if your bottle feeding, I do it untill they are twelve weeks, if they are on the mom she will keep them off but could allow them to eat longer. also at 8 weeks, i back the bottle off to two a day and two weeks later one bottle a day.
I wean at 8-10 weeks on a bottle, or on the dam, depending on how well they are eating hay/grain. I'm usually so sick of bottle feeding by 6 weeks old, that 8 weeks is when I say enough. I may go a little longer if they are on the dam.