> Exactly, and you need rolling resistance for traction.

No, you don’t. Look at e.g. gears: almost no friction, perfect traction.

> Which is why you don't ship hay on trains

No. You don’t ship it on trains because that is uneconomic. You keep your cattle close to your hay producing fields, where they can also graze.

Also, by your reasoning, an empty train would not be able to move?