Popis: |
Groups of Atlantic salmon parr were kept at five different water temperatures; 2, 4, 6, 8 or 10° C. After acclimatisation, they were vaccinated either by injection or immersion against cold water vibriosis, caused by Vibrio salmonicida. Five weeks after vaccination, the water temperatures were raised to 10° C for all groups. During challenge tests 2, 4 and 6 months after vaccination, fish vaccinated at low temperatures (2, 4 or 6° C) showed better protection against infection than fish vaccinated at higher temperatures (8 or 10° C). However, the mean levels of antibodies against V. salmonicida were not higher in the low temperature group, indicating that other mechanisms also play a role in protective immunity. |