You need to have an import licence, just contact NPITS and they’ll send you the relevant forms. The pigs you get must be certified ift by a vet in N.Ireland or the U.K, 24 hrs before departure. When you purchase them you MUST get from the vendor :
1)Animal Transport Cert
2)Veterinary Service Support Cert
3)Intra Trade Cert
4) Declaration from owner that animals have been on his/her holding for a period in excess of 30 days.
They should have all this ready for you. You should allow £40 on top of your purchase price for the vets cert.from the vendor.