No. Grain should only be fed if a) you are wanting to finish them on grain for beef, or b) they are loosing weight and condition on hay, or if the hay is not adequate nutrition enough for lactating...
It is not usually used for horses. Horses do better with Timothy or red top hay. Feed it to the cows. Thresh the grain out, then bale up what is left. Grind up the grain and give it to the cows, or...