So what do you consider to be "cattle hay"?

I see a lot of lower cost hay on CL, including some of mine  

 

1. Exactly what would you expect to be the "downgrade" to hay that makes it "cattle hay".

Higher moisture? Browner appearance? More weeds? Over-Mature stage baling? 

All of the above? haha

 

2. Exactly what is it that beef herd cattle will tolerate that can be in a hay bale that horses (or their finicky owners) wont tolerate? 

 

I'm trying to develop some kind of visual or content difference between what would "downgrade" a bale to cattle hay.

So what do you consider to be "cattle hay"?