In livestock raising if you want to earn more you need to invest more. It is a number, the more the animal you have the more you would earn. Reason behind this is that once you have the volume you could order feeds, medication etc in large volume. Larger volume means larger discount or rebate. At the same time, you could demand a premium in your products because you could supply in bulk.
So my advice, start small and dream big. Usually, most raiser have day jobs and their livestock is just secondary. They would let their investment roll first and when the time that their investment is earning more than or as much as possible 3times their current salary then they go full time.
Another thing about swine raising, usually your money would earn 20% in a year and that is more than what your money would earn when it is in the bank.
If you want a fast pace turn over then go into buy and sell. But this business is more riskier.