运输应激对二花脸和皮特兰猪血浆应激和代谢相关激素水平的影响

比较二花脸和皮特兰猪在2h运输过程中血浆ACTH、皮质醇、胰岛素和T3、T4水平的动态变化模式,以分析内分泌激素变化的品种特征.选用雄性二花脸猪10头,皮特兰猪6头,体重达20kg时安装颈静脉瘘管,1wk后运输试验,运输过程中不同时间点采集血样,放射免疫分析法测定血浆激素水平.上车后两品种猪ACTH水平缓慢上升,60min后达到峰值,下车后15min恢复至基础水平,运输过程中ACTH水平及变化幅度均未表现显著的品种差异;运输前皮质醇水平二花脸显著高于皮特兰猪,上车后两品种皮质醇均迅速上升,出发后15min达到峰值,下车后15min均快速恢复至基础水平,运输过程中皮特兰皮质醇上升的幅度显著高于二花脸猪;两品种胰岛素水平上车后均呈下降趋势,二花脸胰岛素水平总体上显著高于皮特兰猪;T3水平在上车后也表现快速下降,无论是T3水平还是其变化幅度均不表现显著的品种差异;皮特兰猪上车后T4水平稍微下降而二花脸猪显著下降,皮特兰T4水平总体显著高于二花脸猪.运输应激伴随血浆ACTH和皮质醇水平升高,而胰岛素、T3和T4水平下降,皮质醇水平升高的幅度能够反映猪的应激敏感性.图1参25

Effect of Transport Stress on Plasma Concentration of Hormones Related to Stress and Metabolism in Erhualian and Pietrain Pigs

This study was aimed to analyze the breed-specific characteristics of pigs in response to transport stress,through the comparison of the dynamic changes in plasma ACTH,cortisol,insulin,T3 and T4 levels between Erhualian and Pietrain pigs during 2 hours' transportation.Ten male Erhualian and six male Pietrain pigs weighted about 20 kg were fitted surgically with a jugular vein catheter.After one week recovery they were subjected to a 2 h transportation and their blood samples were collected during the transportation for measuring plasma hormone levels by radioimmunoassay.Plasma ACTH levels in the two breeds rose slowly after loading,peaked at 60 min after the start of transportation and then declined tardily to the basal level after unloading for 15 min.Neither ACTH level nor the percentage of ACTH increase exhibited significant difference between the breeds.The cortisol level detected at 15 min prior to the transportation was significantly higher in Erhualian pigs.After loading the cortisol levels of the both breeds rose rapidly,peaked at 15 min after the transportation and maintained high throughout the 2 h journey,then restored to the basal level quickly after unloading for 15 min.The percentage of cortisol increase was significantly higher in Pietrain than that in Erhualian pigs.Insulin levels of the both breeds declined evidently during the transportation and the level of Erhualian was significantly higher than that of Pietrain pigs,whereas no differences were observed in the percentage of insulin decreases between the two breeds.T3 levels of the breeds dropped rapidly after loading,but neither T3 level nor the percentage of T3 decrease differed significantly between the breeds.T4 levels maintained relatively stable and were significantly higher in Pietrain pigs compared with Erhualian.These data suggest that the transportation stress is accompanied by increase in ACTH and cortisol,but decrease in insulin and T3,T4;and the range of cortisol increase reflects the stress sensitivity of pigs.Fig 1,Ref 25