BACTERIAL KIDNEY DISEASE (BKD) is caused by Renibacterium salmoninarum (RS). RS is an intra-cellular bacterium that causes lethargy, ascites, anemia and bulging eyes resulting in reduced growth and performance in affected groups.
Affected fish can be treated with antibiotics, and vaccination is partially effective. Biosecurity and screening of broodstock is used to prevent vertical transmission. Horizontal transmission from infected wild fish is difficult to prevent, especially in cold-water production areas of Chile where BKD represents greater problems.
Benchmark Genetics has started trials to measure susceptibility to BKD in Chile to identify families with better resistance. The company also uses GS to identify individuals with high resistance to the disease for use in the nucleus and commercial ova production. Commercial ova with improved BKD resistance will be available from early 2021.
BENCHMARK GENETICS has carried out studies in the Chilean breeding population which show that BKD resistance has a polygenic structure (Figure 1).
When observing the remarkable mortality difference between the most resistant and most susceptible families, that resistance improvement can be achieved by selecting the best performing individuals with the use of GS (Figure 2).
