Adding oil to my horses' diets?

I've heard that adding some oil to a horse's grain helps them to put on weight and improves their skin and coat condition. I would like to try this with my horses. So my question is can I use just regular vegetable or canola oil?

We give all of our horses oil (except one since he had diarrhea). We give our corn oil and it has greatly improved their coats. They are beautify and shiny and very healthy looking. :)

We give ours vegetable oil. I was told by my trainer to make sure it's 100% soybean.

Iv tryed corn oil and my horses don't like it and wont touch their grain if theres oil in it. I use flax seed instead alot less mess. Do know other people who use corn oil with great results.

My horses LOVE the oils in their feed and I believe it helps to shed them from their winter coats.

I use vegetable/corn oil (whichever one I have a coupon for that week ), two cups a day, one cup per meal I love what it does to the coat (soaks through the skin and saturates it... like when you eat a greasy potato chip and your skin feels greasier. It's kind of like that effect, only not as unhealthy), and its a cheap way to put on more weight without more pounds of grain.
However you shouldn't use it if your horse is swelling. Indie got a rope burn on her pasturn, and her leg swelled up a bit so I had to take her off the vegetable oil since it can actually encourage swelling Put her on extra ACV to mix her feed with until the burn is all healed up and the swelling went right back down. Just a cautionary add-in. Otherwise, I love my vegetable and corn oils :)

Oil contains lots of Omega 6's and not really any Omega 3's. Omega 3 is an anti ant-inflammatory and Omega 6 is a inflammatory. So, if you feed oil, I would HIGHLY recommend adding some additional Omega 3's into your horses diet- you can get the supplements at most horse stores.

Other than that, oil is awesome for adding weight. (when I say oil I mean corn/vegetable)

We used vegetable oil in the OTTB we had at our therapeutic barn to keep weight on her over the winter. It didn't seem to help her, but TB's are always hard to keep fat. I had a friend who used corn oil on her rescue ponies and they fattened right up.