No one ever said, but I have to assume the spreader is wheel driven, not pto driven???? Many of the hitches suggested - 3pt style - do not work with a pto shaft.
The Agri-Speed hitch pictured near the end is pretty popular for hauling wagons, for example combining 40 acres of corn a day, & your wife is hauling wagons away for you. That would be 60 or 70 times to unhook & hook loads. That assumes you always stop right to hook up the full load - unlikely. Probably 100+ times up/down the tractor or pickup.
Wife never shows up for the second day, even if she can walk.
My wife prefers plowing, and so I hook my own wagons. And we are both too poor to afford the nifty hitch.
Hey all, be careful with those 3pt hitch bars. You can't turn real short when hooked to one with a hitch pin, and going down a hill they can _SLAM_ up when the load pushes (downhill or brakes) & wreck things really bad - including you. With a spreader, if the manure stays piled high & moves back, often's the time the drawbar will lift up on me when the back is full, the front is empty.... Using stablizers or chains means you don't get the range of motion you want, so no one uses them. But, it can come back to bite you when the hitch slams upward.
I would be most comfortable with the chain idea, and hooking up to the tractor drawbar.Or, replace the jack with a real farm jack - the type someone described, with the pegged pipes for the 'swivel'.
The 3pt drawbars have their place, but be careful with big loads & pto powered equipment & hills & the like.....
--->Paul