Fish vaccination machines in Norway

Photo: Arild Kollevag

20 June 2006

Solveig Nygaard, Fiskehelse og Miljø AS, Veterinary Specialist - Fish

In the early years of the salmon industry in Norway, vaccination by hand was essentially the only method used to vaccinate fish. However, since then, a number of vaccination machines have appeared on the market and today more than half of Norwegian salmon and trout smolts are vaccinated by machine. 

Based on the experience that the Norwegian industry has gleaned in the use of specific methods and vaccination machines, this article is an attempt to evaluate some of the current machines (as well as manual vaccination). Because of the risk of side effects due to injection vaccination, salmon and trout smolts should ideally weigh more than 40 g at vaccination. As all of the machines considered here use fish of this size, product information related to fish size will not be discussed. 

Basic information

There is most experience with manual vaccination of salmon and rainbow trout. Simple syringes that do not use compressed air are the cheapest, but they are labour intensive and put a strain on the hands of the vaccinators. Syringes that use compressed air cost more at around EUR1,300 each, but they place less strain on the vaccinator and allow for a higher vaccination rate.  The machines from Lumic are currently the most widely used machines for vaccination of salmon in Norway. Lumic entered the market with a 2-line vaccination machine in 1992. Following further development and improvement, it was launched as a 4-line machine, the Lumic LV4, and this is currently the best selling machine. Nordic Fish Tech has been producing machines for the fishing industry for a number of years, and its first vaccination machine was introduced at AquaNor in 2003. So far, only a few machines have been sold in Norway. It is sold mainly to fish farmers in the Mediterranean area.  

The EasyVac 8000 (formerly called Thormed 8000) was developed by Rossi International in Denmark in 1994. The technology has been developed from the first vaccination machine, the SpinoVac 7000, which entered the market in 1984. The machine is sold with 1, 2, 3, 4 or 6 vaccination units. Thirty-three machines were sold in Norway in the 1990’s, and it is still available. 

Vaccination rate, labour requirement and functionality        

Manual vaccination
In the case of manual vaccination, the vaccinator usually places the fish in a belly-up position for vaccination. Some vaccinators prefer to have the fish on its side on a table during injection. The author is not aware of any studies where the two techniques have been compared. Professional vaccinators usually use compressed air syringes in order to reduce the strain on the vaccinators and achieve a higher vaccination rate. Experience shows that manual injection vaccination gives very good results as regards the point of injection and vaccine deposition. However, the human factor is key to the result and, in practice, a tired or stressed manual vaccinator will produce a poorer result than that achieved with machine vaccination. Manual vaccination is tiring work with a far greater risk of self-injection than is the case with machine vaccination.  

Conclusion
Manual vaccination can be a quick and reliable vaccination method that does not require the fish group to be well sorted. The result depends more on the vaccinator’s abilities than is the case with machine vaccination. The method is not optimal in terms of working environment, especially as regards physical strain on the hands and the risk of self-injection.

Lumic LV4 
The Lumic LV4 has four vaccination lines which are operated by two people. The anaesthetised fish are lifted out of a line and placed head first into the vaccination chute. The fish slide down a partially enclosed chute into the injection chamber where they are stopped by a cushion. Fish which enter on their back are turned so that their belly points down. The fish are injected intraperitoneally from below at a 45-degree angle. At the start of the chute is a hatch which closes when the fish is being vaccinated. This prevents two fish from coming in at the same time. 

Conclusion
The Lumic LV4 provides a high rate of vaccination and is reliable, provided that the fish are well sorted, that the operator feeds the machine correctly and that the machine is correctly adjusted. If the fish are uneven in size, the point of injection will vary. The machine’s weakness is that it is difficult to accurately adjust the point of injection. The injection depth is the same regardless of whether the fish is large or small, and the vaccination process is hidden from the view of the operator so that any mistakes are not discovered, unless the operator is really on the lookout for them. Development work in the newer machines has made it possible to adjust the point of injection freely, with no fixed intervals, and this function can also be installed in older machines.