Pigs perhaps? Right sort of size, currently being looked at for organ transplant. It really I think if we get to the point where we could use a pig we are more

Pigs perhaps? Right sort of size, currently being looked at for organ transplant. It really I think if we get to the point where we could use a pig we are more likely to be able to build a womb from stem cells and grow a baby in that. I imagine that the latter would be an easier sell to the public, however the former would create quite a furore with 2 of the 3 Abrahamic religions.