Effects of Stunning by Ice and Clove Oil, and Asphyxia on Stress Responses and Quality Indicators in Common Carp (Cyprinus Carpio)

In this investigation effects of two stunning methods 1) ice asphyxia، 2) direct immersion of fish into bath containing previous water dilution of clove oil that were killed by blow on the head were compared with common fish slaughtering

removing fish from water and exposed to the air (asphyxia). Effects of these two methods on meat quality and stress responses in common carp were evaluated. Results revealed that anaesthetizing and killing procedures significantly affected the meat quality in common carp. Both rigor index and pH varied significantly during the trail post-mortem between the experimental groups. Maximal rigor index (77. 6%) was observed after 3 hours post mortem in the asphyxia group. Rigor index reached maximum at 24 (44. 2%) and 60 h (55. 1%) post mortem for the ice and clove oil group. Fish subjected to clove oil showed a less intense than those in the other group although they had a longer lasting rigor state. Mean muscle pH of fish was 6. 34 for asphyxia، 6. 53 for ice group and 6. 99 for clove oil immediately after death. Fish of the group clove oil had the lowest driploss at 96h postmortem. Stress blood indicators in asphyxia group were significantly higher than other two groups and the control group (unstressed fish). The data presented in the experiment expressed that fish of the group received clove oil had significantly higher quality and less stress response than other groups.