Salmon Smolt (Salmo salar L) production and stress reducing measures. The effects of Aqui-S sedation during vaccination, transport and transfer to sea on survivability, appetite, growth, immunological capacity, primary, secondary and tertiary stress responses

A good anaesthesia for vaccination should render the fish inoperable in less then 3 minutes, and the fish should recover from anaesthesia in less than 5 minutes The combination of sedation and anaesthesia with Aqui-S failed to meet these criteria. However the combination of Aqui-S sedation and Finquel anaesthesia gave satisfactory results. During the vaccination experiment three different treatments were tested on Atlantic salmon smolts. Even though the handling and vaccination process gave no negative effects on the vaccine, the stress reducing measures had positive effect on overall stress level, feed conversion, appetite and mortality. Most pronounced was this effect during sedation of Aqui-S followed by Finquel anaesthesia (treatment II). Treatment I gave only minor positive effects on overall stress level, feed conversion, appetite and mortality compared to control, and the prolonged time (60 -90 min) it took this group to reach stage 4 (anaesthesia) will make it hard to implement this into an effective commercial vaccine routine in the Atlantic salmon smolt industry. However higher dosages of Aqui-S in the anaesthesia bath could improve the efficiency and reduce stress levels comparable to treatment II, but this has bee tested. In the on following transport experiment one wished to document the potential effects of Aqui-S? sedation on transport stress and transfer to sea, on survivability, appetite, growth, immunological capacity, primary, secondary and tertiary stress responses. The use of Aqui-S? sedation prior to loading and during transport had a positive effect on the overall stress level with improved survivability, after transfer to sea compared to the non treatment group (control). Most pronounced effect was observed when Aqui-S? sedation was used both during loading and transport. These results are promising and might be useful in the reduction of the excessive loss one experience after transfer to sea in both Norway and Chile. However, this experiment was not done in commercial scale and adapted tests needs to be done during regular smolts transports both in well boats and trucks before one can safely implement this technique.

Til publikasjon: https://hdl.handle.net/11250/4707112 | Publiseringsår: 2005 | Tidsskrift: Nordlandsforskning