If he is at the desired weight, you could remove the grazing muzzle while he is turned out. However, to limit weight gain, you should limit the amount of time the horse is turned out without the muzzle on. If you notice weight being put back on, you should increase the time spent wearing the muzzle. You will probably want to use the muzzle again in the spring because grazing the lush spring pastures will put weight on in a hurry.
