Rob, On a long skinny paddock with water at one end I would put a short cross wire across the width of the paddock and starting at the water end and allow the group only enough area to eat the grass in the first paddock down to 3 or 4" in one day or maybe two. when they get the whole  shortened paddock eaten down to 3 or 4" then put up another cross wire with another days worth further down away from the water  and then take up the old cross wire exposing the new grass at the same time each day.

You will find they will learn to eat everything in the paddock open to them and they will get used to getting more at the same time each day. The group will then be happy to move to the new fresh, non-manured area.

When you limit the area the manure builds up quickly even with a small herd and they will gradually learn to look forward to fresh grass. They will also learn, as Ben has pointed out, a "mob" psychology that tells them if I want the best grass I better get to it before the cow next to me eats it...

The drawback to this no-back-fence system is they are walking through the used areas to get to water. Not as big deal but does trample more grass than you would like. I would use a simple one-wire lane to keep them to one path to the water rather than trampling everything behind them. 

But try the smaller area advanced regularly system first. the cattle need to learn the system. They are naturaly lazy and need to be hungry a bit to learn the system. you will gradually figure out how many paces they need each day at a certain grass level.

As others have said, you need to reduce the area open to them each day. Not a big deal - I use aluminum wire on a Gallagher spool with a gate handle on one end and a few Gallagher pigtail type step-ins for the moved cross wires.

12 pairs on 5 acres is not really going to maximize your pasture carrying capacity. I'm glad to hear the clover is working well for you. It comes on strong when you need it if managed right.

Enticing them to go to the other end of 5 acres is like trying to bribe a spoiled kid with candy - he's not that interested. They need to have just enough to get a bit hungry and look forward to that fresh grass on the other side of the wire they see there...

Good luck.

Jim at Dawn