Personally i feel my business is still to young to do this. I want to focus on growing the business to a particular level first where i can be sure it can stand on its own before i think of going into another business.
As long as you're still new in a business, you will lack both the capital, experience and knowledge to run multiple businesses at once. I have been managing my business of poultry and fish farming for 6 years at the moment and I still don't feel the need to run a multiple start ups at once.