Hello,
You'll need a herd number from your respective Agriculture dept. Usually they will inspect your premises to ensure it is suitable to keep pigs.
As for the profit bit - if you're raising them yourself and selling directly to the public then it can be done. Mind you there will be overheads incurred keeping the right side of your local environmental health dept.
If you are close to a bakery and can get stale/unsold bread for free then you'll be half way there. Raising pigs on feed from an agricultural merchant alone would make it tight to make much profit.
Good luck.
Gavin