Gorewit R C, Scott N R
J Dairy Sci. 1986 Apr;69(4):1122-7. doi: 10.3168/jds.S0022-0302(86)80510-0.
Six Holstein cows in late lactation were used to determine effects of 4-mA square wave alternating current on mammary gland blood flow rate, heart rate, and blood pressure. Current to the lumbar-sacral region of the cows' back was applied 10 s prior to udder massage and throughout milking. Heart rate was measured from systolic pulses (beats/min) off strip chart recordings. Blood pressure determinations were made from carotid arterial cannulae. A single rise in blood flow rate occurred during milkings without current. Mammary blood flow increased (30% with respect to rest) without 40 s of milking. Heart rate and blood pressure did not change significantly. An abrupt increase in mammary blood flow rate, heart rate, and blood pressure was seen immediately upon current application prior to milking. Mammary blood flow rate increased 50%, heart rate 25 beats/min, and blood pressure 33 mm Hg. The response latency was approximately 60 s. A second rise in mammary blood flow (31%) was milking induced, occurring within 42 s of milking machine attachment. Milk yield was not influenced by current. Our data suggest that 4-mA of alternating current, applied prior to and throughout milking, causes an immediate elevation in mammary blood flow rate, heart rate, and blood pressure of cows. Cardiovascular responses are short-lived. Current given throughout milking does not influence normal physiological changes in mammary blood flow during milking.
选用6头处于泌乳后期的荷斯坦奶牛，以确定4毫安方波交流电对乳腺血流速率、心率和血压的影响。在挤奶前10秒以及整个挤奶过程中，对奶牛背部的腰骶区域施加电流。通过记录纸记录的收缩期脉搏（次/分钟）来测量心率。通过颈动脉插管测定血压。在无电流的挤奶过程中，血流速率出现单次上升。在没有40秒挤奶的情况下，乳腺血流量增加（相对于休息时增加30%）。心率和血压没有显著变化。在挤奶前施加电流后，立即观察到乳腺血流速率、心率和血压急剧增加。乳腺血流速率增加50%，心率增加25次/分钟，血压增加33毫米汞柱。反应潜伏期约为60秒。第二次乳腺血流量增加（31%）是由挤奶引起的，发生在连接挤奶机后的42秒内。产奶量不受电流影响。我们的数据表明，在挤奶前及挤奶过程中施加4毫安交流电，会使奶牛的乳腺血流速率、心率和血压立即升高。心血管反应是短暂的。在整个挤奶过程中施加电流不会影响挤奶期间乳腺血流的正常生理变化。
