Bacterial cold water disease (BCWD), also known as rainbow trout fry syndrome or flavobacteriosis, is a serious contributor to losses in the commercial rearing of rainbow trout in almost every region where it is farmed.

Troutlodge, in collaboration with the USDA, initiated research roughly 10 years ago to help solve this issue. The use of genomic selection technology has produced significant improvements in survival through laboratory challenges and Troutlodge strains can provide enhanced resistance to BCWD.

Troutlodge product selected for BCWD resistance has been commercially available since 2017 and is starting to receive positive feedback from its clients. “When Troutlodge offered the first BCWD-enhanced resistance eggs in 2017, we were probably one of the first customers who tried them. Now, three years later, we have had several batches and can confirm all the previous problems we had from time to time with Flavobacteria have simply disappeared in these batches,” said Alexander Tautenhahn from Forellenzucht Trostadt GmbH & Co.KG

“We are seeing indications that the improved survival in laboratory challenges has translated to improved performance in commercial farms. The benefits of increased resistance extend beyond improved survival but also the prevention of BCWD outbreaks have other sustainability benefits, such as reduced antibiotic treatment use and reduced downgrading at harvest due to deformity caused by the BCWD pathogen. Prevention of outbreak also eliminates associated decreases in appetite and growth, leading to faster time to harvest," Troutlodge said.

The expanded use of genomic selection into other strains will be aided by the development of a custom SNP chip for genotyping Troutlodge's broodstock. Coming late 2022, eggs selected for BCWD resistance will be available in the November strain, in addition to the May.