Hi Cobra, I have six of mine going off tomorrow and they were of poor stock also they are 9months now, some boar some gilts GOS they are not massive though I always slaughter at 9months as there is no fat or taint and it keeps the killing costs down and the butchering, I put one of my SB gilts in once and the killing costs was a lot because she was so big, I also give them cows milk 3 times a week or more if you can, also Cider vinegar makes the meat takes superb.
Thats very reassuring and I'm glad yo mentioned it because I know how many people are concerned of taint. Don't get me wrong it happens, but its not just age its also sexually active resulting in higher hormone levels, and yet mine were fine. I had considered milk at one point, but we don't produce our own sadly and it illegal for me to bring it in and feed it, did you find The first time you did it the pigs turned pale almost white?
Years ago I fed milk to a pig and the bugger literally turned white
but wow did she grow and lovely result.