Differential Pressures Across the Bovine Teat Canal During Three Methods of Milk Removal

Abstract Two cows and their 10- and 15-day-old calves were used to compare the differential pressures and the sequence of events during mechanical milking, hand milking, and calf suckling. A pulsator rate of 48 per minute and a milking vacuum of 12.5 in. Hg were used during mechanical milking. The average frequency of hand milking and calf suckling was 67 and 117 cycles per minute, respectively. Average differential pressures across the teat canal were 310 mm Hg for hand milking, 352 mm Hg for mechanical milking, and 535 mm Hg for calf suckling. The udder appeared to be evacuated most rapidly during calf suckling, which was attributed to the rapid suckling cycle and the high differential pressure across the teat canal.