Horse Treadmills refrigeration, milking parlor and machine/wood shop

Hello
I’m interested in learning more specifics about practical horse treadmill application. I have read of them for awhile and saw the live demonstrations at the last horse progress days.

I read that a few people are powering their milking machines and cooling there bulk tank with one. Does the horse have to be walking while the milking is taking place to create vacuum or can the vacuum be stored for later use? I also heard that a horse has to use the treadmill for 1-2 hours every other day to keep a freezer cold. Is this accurate and approx how much would a horse have to walk to keep a 50-100 gallon bulk tank cold?

I have seen tools run off of the treadmill as well, mostly pneumatic. In my area pneumatic shop tools are pricey and uncommon (besides pneumatic hand tools). I am assuming older belt driven tools could be used as well? Is there a way to convert these to run pneumatically too (a drive pulley that runs pneumatically?) or do you just wheel them around the shop to a common drive pulley). I’m assuming the only way to run electric tools that aren’t belt driven is with a battery bank. I’m trying to determine what would be efficient, practical, and reasonably affordable.