We are ready to purchase more hay. We usually get great alfalfa hay through a friend of ours when they order it for their horse. This next shipment is supposed to be alfalfa and grass mix (a grass that has protein a little lower than Timothy). Here's the ???... My 20 month old heifer is due in Aug. Should I stick to alfalfa and find another source for it or will the grass mix be okay for a bred heifer that is still growing herself? I also give her dairy 14 grain once a day. Thanks.