二花脸仔猪在运输过程中的行为特征和血浆皮质醇水平的变化

本试验采用实时跟踪摄像和颈静脉血管瘘连续采样,观察二花脸断奶仔猪在2h运输过程中的行为表现,并测定血浆皮质醇水平的动态变化。结果表明:运输前期(出发后15min)仔猪的探究行为和异常行为发生次数较多且持续时间较长,运输中期(出发后60~75min)此类行为显著减少(P<0.05),而到运输后期(最后15min)几乎观察不到此类行为;仔猪的躺卧行为在运输前期和中期发生次数较少,持续时间较短,而在运输后期仔猪大部分时间都处于躺卧状态(P<0.05);运输至中期仔猪大部分时间处于站立状态,而到运输后期站立行为显著减少(P<0.05);仔猪蹲坐行为发生的次数和持续时间在运输的前中后无显著差异(P>0.05)。仔猪上车后皮质醇水平迅速上升(P<0.05),出发15min升至峰值,且保持该高水平直到2h运输结束,下车后15min皮质醇水平迅速下降至上车前15min的基础水平。

Behavioral Characteristics and Changes of Plasma Cortisol Levels of Erhualian Piglets during Transport

Weanling Erhualian piglets equipped with chronic catheters in jugular vein were subjected to 2 h of transport.Behavioral exhibition of the piglets was recorded with a video camera throughout the transport and dynamic changes of plasma cortisol levels were measured with RIA.The results showed that during the first 15min of transport,the cumulative time of the exploring and fit behavior were significantly longer(P<0.05) than that observed during the middle and the last 15 min of transport.Piglets expressed hardly any fit behavior but spent the majority of their time lying during the last 15 min of transport.Piglets were seen standing most of the time during the first hour of transport.However,sitting behavior did not show significant difference across the 2 h transport in either the cumulative time or the frequency.Plasma cortisol levels rose rapidly after loading,peaked at 15 min after transport and maintained high throughout the 2 h journey,then restored to the basal level 15 min after unloading.