2.2. Fish in Material II
A separate immunisation experiment was carried out at Sunndalsara based on 27
month old Atlantic salmon (Material II). These fish were full-sibs to some of the
families in the 1986 year-class of the national breeding program. The families were
chosen to represent 57 full-sib groups within 20 paternal half-sib groups. A total of 1200
fish were included in the experiment. The different full-sib groups were reared separately
for 8 months (post hatch) and then tagged and reared in one common tank. When
the fish were 26 months old (post hatch) the fish were randomly distributed in three 2.5
m3 tanks. The fish were reared in freshwater for one year and further reared in brackish
water with a salinity of 15 ppt. During the freshwater period the fish were vaccinated by
the immersion method against vibriosis with a commercial vaccine.