Do horses eat straw

Actually, if there is nothing more interesting to eat, cows and horses will certainly EAT straw. Straw is often used as bedding in horse stall, and many horses eat it. However, straw has about as much nutrition as foam packing peanuts and horses and cows cannot live on such a deficient diet. It's a bit like asking if children eat dirt. Of course they do, but they couldn't live on it. Hay is the proper fodder for farm animals.

No, farm animals like horses and cows eat hay, which has nutritional value, but do not eat straw.