DYNAMIC-RESPONSES OF THE DAIRY-COWS TEAT TO STEP CHANGES IN PRESSURE

Dynamic responses of the teat end, measured as changes in external diameter and milk flow-rate, due to step changes in pressure, uniformly applied to the whole teat, are presented. The experiment involved a front and a rear teat of each of 6 Holstein-Friesian cows. The measured variables were: (1) step change in pressure, (2) milk flow-rate, (3) step change in external teat end diameter, (4) rise times of pressure and teat end diameter changes, (5) fall times of pressure and teat end diameter changes, and (6) delay times between pressure and teat end diameter changes both at start of rise and of fall times. A statistical analysis showed that front teats expanded more than rear teats (P < 0-05). Several other findings of importance to any system of milk removal through the streak canal of the teat are discussed. © 1979, Proprietors of Journal of Dairy Research. All rights reserved.