Depends on who installs it. If you do, you get to add the fluid. It won't be a huge amount - just whatever it takes to fill the hoses. If your dealer does, they should top up your tractor. You might want to double check that...
Not a ton of fluid, but more than just the hoses. You also have to fill the cylinders with fluid. Probably in the range of 3 gal extra, probably less. At the price of the hoe, the extra $ for the fluid has to be included!