If you've got 22 1300lb cows that's 28600 lb of cows.  If you use 30,000 lb of cows at 3% of their body weight per day, you will need 900 lb of hay per day. 3% is conservative which is a good thing to be when figuring hay needs. Allows for some waste on bale OD, bad weather etc.

Oct-Apr = 7 mo x 30 = 210 days.   210 days at 900 lb/day = 189,000 lb of hay or 95 tons.

You should allow 95 tons of hay per winter.  Depending on the size and density of the bales you make or buy, the number of bales required will change.  You are safer figuring hay by weight rather than bales unless you know the weight of your bales.  I've weighed 4x4 dry round bales around 750-800 lb and 5x6 dry round bales up to around 1600 lb.  Even in the same size bale, bale weight can vary widely.

Knowing the tons of dry hay you need, you can work out how many acres you need once you come up with a dry hay yield per acre for your area. The local extension office should be able to help you estimate a hay yield for your type of hay and location.

Good luck.