My mare gets a tbs of corn oil with her 1lb of E-Tech feed morning and evening. It's sort of a reflexive thing- all the horses where I board get the oil added. The barn owned my mare before I bought her a few months ago, so I've just sort of stuck with what she was being fed.
I started thinking more about the oil thing today though. I can't come up with any reason she needs the oil; she's definitely not trying to gain weight and she's not a hard keeper. In fact, the vet thinks she really still needs improvement in her overall conditioning (i.e., decreasing her belly). He wanted her to stay on the grain since we were having some problems with hay quality (those have since been addressed), but now that I think about it, I never discussed the oil with him.
It's such a small amount, I can't imagine it's really affecting her overall condition one way or the other, but I'm inclined to just cut it out. Thoughts on that?