Horse manure is in the form of multiple buns, each about the size of racquet or squash balls. Cow manure is much wetter, and comes out as large, wet cow flops. Steers are indeed cattle. They are exactly bull calves neutered early in life. I know, as a youth, for many (too many) years I assisted at the cutting and branding of hundreds of them. Female calves become heifers, and are bred as yearlings to produce calves and become cows. Steers, heifers, cows, and bulls are all cattle. And they poop wet flops. I invite all readers to examine horse manure and cow manure, and smell it. Based on their their own examination, make an informed decision on whether they would allow steers and therefore cow flops on the trail.