Corn oil is best for horse.It is good for many diseases.it prevents the horse from many diseases.It is good to use corn oil.
Everyone else seemed to answer everything well. I'll just add that I had my girls on garlic powder last winter and it really helped with flies. This summer, I'm trying Apple Cider Vinegar. I've been giving it for a month and don't see much helpfulness, so when I'm done with this jug, I'll probably go back to garlic. =]