Though too much Omega 9 is bad, your horse DOES need it. Inflammation is acutally a necessary part of the healing process. So, feeding about 1 cup a day would most likely be safe and effective if you were just looking to improve coat health.
Hmmm.....Interesting. The hay tested great with tons of protein. (My Father has raised fertilized coastal for 30 years). The folks at Texas A&M Equestrian Facilities put me onto the oats/omega supplement. They analyzed the hay for me, so I would hope they would mention that. In Texas, we don't raise as many grasses as people from cooler climates. (Mainly Timothy and Coastal~we ship in some Alfalfa) Mine are fat and sassy, so hopefully it's working.