I've been told to wait 2-4 weeks before feeding new hay, but desperate times call for desperate measures and when you are out of hay, sometimes you go against all you've been told. We have a small patch of grass here that we can't get the baler in, but we can swathe it; so Shayne's swathes it, I let it dry in the windrow, then pick it up with a pitchfork and toss it into the pick-up and then make a pile of fresh hay by the mini pen. I've done this for several years with no problems feeding it right out of the field. They love it. It only makes a couple weeks worth of hay, but it gets me from one hay season to the next (or from the end of round bale availability to the new squares being available).