Randomized clinical field trial of a bacterial kidney disease vaccine in Atlantic salmon, Salmo salar L.

Abstract

A randomized, blinded clinical trial was performed to assess the relative effectiveness of five commercial and one experimental vaccine in a population of farmed fish experiencing a bacterial kidney disease (BKD) outbreak that occurred in one study cage that was part of a larger clinical field trial. A total of 6000 uniquely identified Atlantic salmon S1 presmolts were randomly assigned to vaccine groups in the hatchery and transferred to a commercial marine aquaculture site. Repeated sampling events to evaluate growth, inherent physical conditions and health status were carried out over the entire production cycle. During the second summer at sea, the study cage developed an outbreak of BKD that lasted approximately 240 days. The effectiveness of the selected vaccines was evaluated using survival analysis methods. The sole vaccine group offering protection for BKD was found to significantly decrease the hazard of dying (hazard ratio, HR = 0.68, P = 0.018) during the outbreak, compared to the industry standard, vaccine group. Additionally, during the outbreak, fish with a shortened operculum had a significantly decreased hazard (HR = 0.38, P = 0.033) compared to those fish with a normal operculum, while fish with jaw deformities had a significantly increased hazard (HR = 2.55, P = 0.001) compared to fish with normal jaw status.

Skeletal anomaly assessment in diploid and triploid juvenile Atlantic salmon (Salmo salar L.) and the effect of temperature in freshwater

“…Finally, in regards to welfare of fish affected by jaw anomalies, although it is has not been investigated whether SJ may impact fish performance, some studies showed that LJD can slower growth (Bruno ; Burnley et al . ) and affect respiration and swimming ability (Lijalad & Powell ). Furthermore, the presence of evident jaw anomalies decreases the value of fish on the market (Benfey ).…”

“…Nevertheless, Fjelldal et al (2015) demonstrated that triploid Atlantic salmon have a higher P requirement than diploids, especially during the juvenile stage. Finally, in regards to welfare of fish affected by jaw anomalies, although it is has not been investigated whether SJ may impact fish performance, some studies showed that LJD can slower growth (Bruno 1990;Burnley et al 2010) and affect respiration and swimming ability ). Furthermore, the presence of evident jaw anomalies decreases the value of fish on the market (Benfey 2001).…”

Concurrence of lower jaw skeletal anomalies in triploid Atlantic salmon (Salmo salar L.) and the effect on growth in freshwater

“…In particular, Bruno () and Burnley et al . () observed that Atlantic salmon affected by jaw anomalies had a slower growth compared to fish with a normal lower jaw although the assessment was anecdotal. Recently, Taylor et al .…”

“…Lower jaw skeletal anomalies have been linked to reduced growth and impaired respiration (Bruno ; Lijalad & Powell ; Burnley et al . ; Boglione et al . ).…”

Evaluation of external operculum loop tags to individually identify cage‐cultured Atlantic halibut Hippoglossus hippoglossus in commercial research trials

“…The real benefits of individual identification, however, are most realized in aquaculture trials in which fishes are held captive and can be re‐sampled with relative ease throughout the production cycle. This allows the use of robust longitudinal statistical methods to determine the effect of fish level treatments (Burnley et al , 2010).…”