Cows give priority to resting over feeding, says peter krawczel, graduate student at the Miner Institute in Chazy, N.Y. Research shows that overstocking results in an increasing percentage of cows standing idly waiting for access to free-stalls. “There is a potential for cows to spend more time waiting for a stall to become available than engaging in feeding over the course of a day,” Krawczel says. Bottom-line: Cows need 10 to 14 hours of lying-down time each day.