Thank you for your response! :) The information about semen is EXTREMELY helpful, thank you. I think I will try the quietex today and see how it works out.
I have taken the "herd" advice into consideration, trying every possible way to settle him. He is penned next to two mares (in foal) that were bred by him earlier in the year. This does seem to help some, as it does give him his little "herd".
However, we have several mares that are bred, but they have foals on their side, and he's been known to react violently toward foals - those mares are penned very far away to prevent an accident. Every time he gets a whiff on the wind, hears a whinney, or sees the swish of a tail he's pacing the fence for two straight hours screaming his head off. Uck, Stallions... hopefully the quietex will give us some peace!
I will post a verdict!