电刺激对肉牛行为和生理指标的影响

Effects of the electrical stimulation on the behavioral and physiological performances of the beef cattle

为研究电刺激对肉牛行为和生理指标的影响,确定约束肉牛放牧边界的作用电压。以内蒙古鄂尔多斯“草原红”肉牛为研究对象,佩戴电击项圈遥控释电作用于肉牛脖颈下部进行电刺激,分别设计466、1723、2050、2865、4204 V等5个梯度电压,利用无线脑电监测系统对肉牛在不同电刺激前后的体温、心率和脑电波进行监测分析;在试验舍内设计虚拟围栏饲养肉牛,运用摄像系统记录试验过程中肉牛活动行为,基于动物行为观察分析软件对肉牛典型行为(转身、停止、停下慢慢转回去、立即停止向后移动、跳跃)进行统计。结果表明,不同电刺激下,肉牛受到电击前后的体温变化不显著(P>0.05);肉牛受到2865和4204 V电刺激时,心率变化具有显著性差异(P<0.05),与电刺激前相比分别提高了26.3%和35.3%,达到104.32、108.83 bpm;脑电信号的β波在466和1723 V电刺激前后的变化较小,自2865 V开始出现剧烈变化。在试验舍内设计区域虚拟围栏,2865 V电刺激时肉牛触发虚拟边界的次数是93次,出现转身、停止、停下慢慢转回去、立即停止向后移动行为分别占被统计行为总数的33.33%、12.02%、9.29%、31.69%,可有效阻止肉牛继续迈出边界。根据肉牛行为和生理指标的变化,作用电压适宜值在2865 V左右,研究结果为进一步精准确定约束肉牛放牧边界的作用电压适宜范围提供科学依据。

Electrical stimulation has been one of the innovative techniques in grazing management. This study aims to explore the effects of electrical stimulation on the behavioral and physiological performance of the beef cattle. The action voltage was also determined to constrain the grazing boundary of the beef cattle. The ‘Grassland Red’ beef cattle in Ordos were used in the experiments, the electric stimulation was carried out from the lower part of the neck with the beef cattle via wearing the electric shock collar. The beef cattle were allocated to four voltages with 4 66, 1 723, 2 050, 2 865 and 4 204 V at which na?ve beef cattle underwent training as experimental groups. An electrical stimulation was administered when the animal entered the exclusion zone, followed by a shock if the beef cattle continued to proceed. The beef cattle were randomly selected for each experimental group and the control group(no electrical stimulation). A wireless Electroencephalogram(EEG) monitoring system was utilized to monitor the body temperature, heart rate, and brain wave of the beef cattle before and after different electric stimulation. In the experimental arena, three beef cattle were fed in an experimental arena with the virtual fence boundary line, and their body behaviors were recorded by a camera system synchronously. A behavior observation and Analysis Software was selected to analyze the behavior characteristics of the beef cattle(turning round, stopping, stop and slowly turn back, stop moving and back immediately, and skip, flick, blink, shake head). Results showed that there was no significant change in the body temperature of the beef cattle before and after different electric stimulation. Specifically, while the voltage was set to 466, 1 723 and 2 050 V, the heart rate of beef cattle before and after electrical stimuli did not change significantly. Once the beef cattle were subjected to the electrical stimulation at 2 865 and 4 204 V, the heart rate increased significantly by 26.3% and 35.3%, which were reached 104.32 and 108.83 bpm, respectively. By contrast, there were small changes in the β-wave of electroencephalogram(EEG) before and after electrical stimulation at 466 and 1 723 V, respectively,but dramatic changes were found over 2 865 V. The frequency that the beef cattle triggered the virtual boundary with 2 865 V electrical stimulation was 93 times, of which the total behaviors of turning round, stopping, stop and slowly turn back, stop moving and back immediately accounted for 33.33%, 12.02%, 9.29%, and 31.69%, respectively. When 4 204 V was used for electrical stimulation, the performances of all behaviors accounted for 38.60%, 5.12%, 19.07%, and 21.86%. Overall, the electrical stimuli of 2 865 V could effectively prevented the beef cattle to cross the boundary and to enter the exclusion zone.Our research results can provide a strong reference and application potential for beef cattle grazing management in grassland.