Hiya
First thing I'd say is, if they were deemed 'meat' pigs by the original breeder it's probably because they weren't good enough to be bred from and the fact that they're both the same age, I'd presume they are brother & sister
You'd probably best to think about sending the boar off asap - this stops any further mating (and potential in-breeding problems in subsequent litters)
Berkies are nice pigs
Alert, cheeky and inquisitive. They do fine outside and being dark haired, don't suffer sunburn the way the white pigs do (we had them through a hard Scottish winter without issues)
They usually go as 'small pork' around 5 or 6 months - typically somewhere around 60-70Kg. I think the Berkshire club website has a bit of feeding/weight info.
The meat was lovely, though ours were fat
(fatter than our Kunekunes) so don't be tempted to overfeed
Berkshire Boy will be along soon no doubt - he'll be able to give you loads more help & advice. We only had 2 gilts, intended for breeding, but we never managed to get them in-pig
by then we'd grown kinda attached to them and kept them on longer than we should have
Good luck and keep us posted !
Karen