IMO, roll out whatever hay the cows will clean up in a day. If they clean up every speck, feed a little more the next day. If they leave some and crap on it, back off some.
Quality/composition/age of hay combined with weather and pasture quality/availabilty makes hay consumption infinitely variable.
Obviously cattle will consume less hay if they are fed in a fresh winter pasture with good grazing and it's a dry winter day, the sun is shining, with calm winds and 30 degrees.
Opposite scenario: With grubbed off pasture, fridgid cold, 3 feet of snow on the ground blowing around, -30 air temp with -50 wind chills, and no sun to be seen, those same cows may need 2 or 3 times as much feed just to stay even.
To summarize: Simply be observant, and your cows will tell you how much to feed them. :2cents: