The reason that southern grasses aren't as potent as western grasses is the moisture content. A cow can only hold so many pounds of grass.

When it's high in moisture the cow simply cannot hold as much. She must let the moisture pass through her digestive system before she can load up again.

But I've never heard of a cow that's grazing 24 hours per day on grass and not be able to sustain herself.  That's a new one on me.  :???: