The Effect of Handling and Transport of the Concentration of Glucose and Cortisol in Blood Plasma of Common Carp

Abstract

Svobodova Z., P. Kalab, L. Du‰ek, B. Vykusova, J. Kolafiova, D. Janou‰kova: The Effect of Handling and Transport on the Concentration of Glucose and Cortisol in Blood Plasma of Common Carp. Acta Vet. Brno 1999, 68: 265-274. The aim of this contribution was to assess the degree of stress in common carp (Cyprinus carpio, L.) exposed to handling and transport. Cortisol and glucose concentrations in blood plasma were used as stress indicators. In some cases, concentration of ammonia in blood plasma and relative weight of spleen (SSI) were used as well. Within handling, an effect of time pause (0; 2 and 5 min) between catching the fish from water and blood sampling for stress indicators was checked. Another goal was to assess the effect of Menocain anaesthetics on the stress indicators. An open system of a 10-hour transport in a special long-distance live fish transport truck (Transport I a II), and a 2-hour transport in classic transporting tanks (Transport III) were compared. Temperature and oxygen concentration in water was measured during transport. After handling the fish prior to blood sampling (2 and 5 min pause), the cortisol concentration dropped significantly (p < 0.001) and the glucose concentration significantly (p < 0.001) increased compared to values in fish sampled immediately after catching. No effect of anaesthetics on cortisol concentration was proved. On the contrary, the glucose concentration fell (p = 0.012) in the anaesthetized fish. After a 10-hour transport in a special truck (Transport I), a significant (p < 0.001) decrease of the cortisol concentration was found, as well as a significant (p < 0.001) increase in the glucose concentration in blood plasma. In the course of 10hour transport in a special truck (Transport II), the majority of carp was found dead. Suffocation and ammonia autointoxication due to loading the fish with full digestive tract were the most probable causes of the fish mortality. After a 2-hour transport in transporting tanks (Transport III) both the cortisol concentration and relative weight of spleen (SSI) dropped non-significantly while glucose concentration in blood plasma significantly (p < 0.001) increased. Results showed that both handling and transport are important stressors in the common carp. Preventive measures were proposed aimed at alleviating the negative effects of these stressors.