If you are talking about the universal tractor hydraulic fluid.. then use.. I use it in my tractors.
I use it in the yanmar, and my NH 1920, and my ford NAA. No problems.. no leaks.. etc.
If you look on the side label, it will give you what specs and manufacturere oils it is considered a replacement for.. for instance.. it specifically states that it meets or exceeds oems specs / is a replacement for the ford/NH m2c134d hy-tran oil, and also the jd303 spec.. etc. Tons of manufactureres are listed. Just take the kubota oil spec/part number with you and see if the oil meets those specs/mentions it as a replacement.
I've not used their regular plain 'hydraulic fluid' like for jacks, etc. As my power steering systems also specify the tractor fluid.. etc.
Soundguy