I'm not a dairyman, but I've sold lots of hay to dairies.

Here in Nevada, we don't use RFV for hay sales. We use the California TDN method, plus crude protein. In California, TDN is simply an inversion of ADF. If the ADF is < 27.0, and your CP > 22%, then you have "supreme" hay and that's the top of the hay market.

The California dairy nutritionists seem to have determined that the ADF and CP are the only two things they care about in hay quality. They don't care about the NDF measurement (part of what goes into RFV). What the California dairymen care about first and foremost is getting the ADF down, as long as the CP is 20% or higher. High fiber limits how much feed you can put through a cow.

Next thing they want is CP > 20% (always) and 22% or higher (best of the best). But CP optimization comes second to low ADF's.

Now, on my hay tests, the lab puts in RFV's. I've sold a plenty of top-of-the-market hay with RFV's in exactly the range you're talking about, and it was graded "supreme" by the California dairy market - ie, top-dollar hay.

Part of the problem is in the RFV computation, which includes both ADF and NDF, as well as a measure of digestible matter. 

This is where I could go off on one of my [in]famous rants on forage sampling, laboratory tests, the forage quality standards, dairymen, etc. But I'll spare you all of that. Let me just inject that my buddy who moved here from Wisconsin, Dairyfarmer John, (of the antique tractors on the other page) told me that in his experience as a dairyman, he spent less time (day to day) looking at forage reports and more time looking at cow poo to determine whether he had the right stuff in the feed. He likes to talk about the consistency, how it falls, what the cow plop looks like, how it sounded hitting the parlor floor... you could say that knows cow poo.

That's straight from a born-n-bred dairy guy, so I have to defer to his expertise on the, uh, subject matter.