I can imagine that the roughage/energy-fat ratio would be limiting as well. If you are feeding a great deal of oil (which by nature is high in energy) you would be struggling to providewhat is needed in other area's of the diet.
I know that I am limited in feeding by the availiable energy in the pasture or even Hay that is provided.
If fed anough roughage in the diet necessary, I would be peeling the horses of the stable roof......as I like feeding oil
I have a horse here at the moment that is needing the extra provided by the oil - but my other priority is keeping her roughage VERY high - as is important with a horse in very poor condiditon, and it also appears to be the absolute undeniable crux of her condition.
Also - due to her current condition , I am reluctant to over feed high energy feed as the condition of her digestive system is in question, and keeping her in a balanced mental state is of utmost importance to enhance the uptake and digestability of what is provided to her
...so that balance is between the perfect energy provision for her......and the cons that come in the same drum as the oil.
I hope that made some sense