From a conversation email of a knowledgeable man, Najib Khan Surattee with a Non-Muslim, why pig is created if it is prohibited to eat and unclean?
From the book Noah’s Ark and the Universal Deluge:
‘Pig did not exist before the deluge, but Allah created the pig in the Ark because the Ark was filled with filth and human excrements that pervaded and unbearable stink. The people of the Ark could no longer bore the bad smell, so they complained to Prophet Noah (May peace be upon him). Therefore, Noah passed his hand on the back of the elephant and lo! The pig came out from the anus of the elephant. The pig complied with the Instructions of Allah, it consumed all the filth and the human excrements within the Ark and the stink disappeared.’
This is why we are forbidden to eat the meat of the pig as it is unclean for us. 4 verses in the Quran and Bible mentioned about prohibition of eating pork and touching them. May Allah increase our knowledge more. Aamin!