Some of your responses amaze me!

Horses can eat it because they can pass the gas. Cows can't pass the gas so will bloat, suffocate and die. You CAN puncture them on the RIGHT side in front of their hip bone in that hollow area behind their ribs and let the gas out. It works best if you insert a tube of some sort to hold the opening open until the gas quits forming. IF cows are on the grass before it comes up in the spring (won't work in the south where it never dies!) their systems adjust to it and they can graze it all year. Put them in later and watch them die! Hay is not often a problem, but I would avoid it like the plague, because it will bring seeds to your place and you will battle Johnson grass the rest of your life.