I have been spring strip tilling corn on grazed corn for several years now on very heavy WI clay hillsides and do not find compaction from the cattle grazing to be a problem other than in front of gates, lanes etc.  

We do get the ground freezing fairly deep most winters.  I originally tried to get them off the corn in early March as the frost goes out. However that didn't work well with my cattle program and this past year I left them on the corn until mid April.

It may be the fact that in continuous corn strip tilled, moving back and forth 15" each year, that the cattle are generally walking on last year's rootballs....

What ever the reason in my system compaction from grazing corn does not seem to be a major problem.  

If there was major tillage in the system then maybe hoof compaction might be more of a problem.  I don't understand why but it seems not to be a problem for me.

Jim at Dawn