Actually tribal people in New Guinea raise pigs by feeding them from lactating human mothers. But pigs are very highly prized there, so I think they look upon the breast feeding with different eyes. Also, Islam, Christianity and Judaism (the Abrahamic faiths) have the same roots. There is the same caution against representing living things in all three religions ("thou shalt have no graven images"). This is mostly ignored in Christianity, but in Islam it is more strictly adhered to. That is why you see alot of Islamic art and architectural decoration have geometric designs.