Join Date: Dec 2010
Location: southern Arizona
I think it really depends on the horses.
We have mixed two horses after a day without a problem. We have also needed to wait several months with the two horses separated by a corral panel before they would mix. And we have had two horses that mixed fine for several months, but slowly developed a genuine hatred for each other (rearing when fighting, for example), and had to be separated. Even then, they would look for a chance to attack the other horse, so I ended up selling one.
Both of those horses, BTW, got along fine with others. The one I sold was immediately put in a corral with 2 other horses with no trouble at all.
My Arabian mare was originally sold to someone who put her in a pasture with several much larger geldings (1200-1500 lbs). She weighed 900 at the start, and a couple of months later was down below 800 because she would NOT submit. She was then returned, and I bought her a few weeks later.