At 500kg, you're no longer managing individual feeding-cycle bags — you're building a proper seasonal reserve. This size suits medium dairy farms that want most of their fodder storage consolidated into a handful of large bags rather than dozens of small ones, cutting down on the labor of packing, sealing, and tracking many individual units.
The trade-off at this scale is exposure time once a bag is opened: a 500kg bag needs to be worked through steadily once unsealed, since a large surface area is now exposed to air. Farms at this capacity typically plan their feeding rotation around opening one bag at a time and working through it fully before starting the next, rather than opening multiple bags simultaneously.