 It is usual to restrict the twice-daily milking to a maximum of an hour and a half each time.It makes no difference whether one milks 10 or 1000 cows, the milking time should not exceed a total of about three hours each day for any cow as they should be in stalls and laying down as long as possible to increase comfort which will in turn aid in milk production.A cow is physically milked for only about 10 minutes a day depending on her milk letdown time and the number of milkings per day.