Grandin T
Department of Animal Science, College of Agriculture, Colorado State University, Fort Collins 80523, USA.
J Am Vet Med Assoc. 2001 Sep 1;219(5):608-11. doi: 10.2460/javma.2001.219.608.
To determine causes and solutions for return-to-sensibility problems after electrical stunning in pigs.
Case studies.
6 federally inspected pork slaughter plants.
100 to 200 pigs were scored in each plant for stunner positioning, squealing when stunner was applied, and signs of insensibility. All pigs were held in a V-shaped restrainer conveyor and stunned with a manually applied head-to-body electrical stunner.
Percentage of pigs that had blinking after stunning ranged from 0.5 to 7. None of the pigs had a righting reflex or kicked in response to stimuli. All signs of possible return to sensibility disappeared before bleeding pigs reached the scalding tub. Spontaneous eye blinking was eliminated by improving bleeding practices to increase blood flow, ergonomically redesigning the stunner operator's work station to make correct placement of the stunner easier, redesigning the head electrode to facilitate correct placement, reducing line speed from 1,200 to 1,080 head/h, correcting problems with poor initial contact of the stunner, and increasing amperage of a stunner that was set too low for sows. In 1 plant, a fatigued operator was the cause of stunner placement mistakes that resulted in signs of returning to sensibility.
Problems with electrical stunning can be easily corrected, but effective stunning requires monitoring of correct electrode placement, amperage, and bleeding procedures. Observation of spontaneous natural eye blinking without touching the eye is recommended for use under field conditions, because it is less prone to misinterpretation than are other methods.
确定猪电击致昏后恢复知觉问题的原因及解决方法。
案例研究。
6家联邦检查的猪肉屠宰厂。
在每家工厂对100至200头猪进行电击器定位、电击时尖叫情况及昏迷迹象评分。所有猪被置于V形限位输送带上，用手动操作的头身电击器致昏。
电击后仍有眨眼的猪的比例为0.5%至7%。没有猪有翻正反射或对刺激有踢动反应。在放血猪到达烫毛池之前，所有可能恢复知觉的迹象都消失了。通过改进放血操作以增加血流量、从人体工程学角度重新设计电击器操作员工作站以使电击器更容易正确放置、重新设计头部电极以利于正确放置、将生产线速度从每小时1200头降至1080头、纠正电击器初始接触不良的问题以及提高对母猪设置过低的电击器的电流强度，消除了自发眨眼现象。在1家工厂，一名疲劳的操作员是电击器放置错误的原因，导致出现恢复知觉的迹象。
电击致昏问题易于纠正，但有效的致昏需要监测电极的正确放置、电流强度和放血程序。建议在现场条件下使用观察自然自发眨眼而不接触眼睛的方法，因为它比其他方法更不易产生误解。
