in the end it is up to the slaughterhouse what they accept and what they reject BUT
all pigs once through the scalding tank lose there pigmentation black hairs are more noticeable if left in than white hairs there system is not very good the SVS can condemn the carcase if to hairy and there is a reluctance to singe them in the UK European slaughterlines have singers gas burners
sheep on the other hand are skinned it is maybe kunnies that they don't like they are hairier than others well with the exception of mangalitsas but some of them are cream you could ask if they would skin them