Southwick L H, Wilson D J, Sears P M
New York State College of Veterinary Medicine, Quality Milk Promotion Services, Cornell University, Ithaca 14850.
J Am Vet Med Assoc. 1992 Aug 1;201(3):441-4.
A dairy farm located in central New York was visited because of complaints of electrical shock in the farmhouse shower and the milk house sink. As much as 2 volts AC of potential difference was measured between the waterline and the cow platform (cow-contact voltage). Voltage was coming from the primary neutral wire. The farm's electrical service was modified so that the farmstead could be connected or disconnected from the primary neutral wire at 2-week intervals for 12 weeks. When connected to the primary neutral wire, voltage between waterline and floor ranged between 0 and 1.8 volts, producing estimated current flow through cows of 3.6 to 4.9 mA; when disconnected from primary neutral wire, voltage between waterline and floor was less than 0.1 volt. There was no difference in mean milk production, bulk tank milk somatic cell count, or water consumption among periods when cows were exposed or unexposed to voltage. Despite statistical nonsignificance, the values for somatic cell count were lower and water consumption was higher when cows were exposed to voltage than when they were not.
纽约州中部的一家奶牛场因农舍淋浴间和挤奶房水槽出现电击投诉而接受检查。在水管线和牛平台之间测得高达2伏交流电的电位差(牛接触电压)。电压来自初级中性线。对该农场的电气系统进行了改造,以便在12周内每隔两周将农场与初级中性线连接或断开一次。连接到初级中性线时,水管线和地面之间的电压在0至1.8伏之间,估计流经奶牛的电流为3.6至4.9毫安;从初级中性线断开连接时,水管线和地面之间的电压小于0.1伏。奶牛接触或未接触电压期间,平均产奶量、储奶罐牛奶体细胞计数或耗水量没有差异。尽管统计上无显著意义,但奶牛接触电压时的体细胞计数较低,耗水量较高。