Breakthrough hailed in rainbow trout disease prevention

Italian biotechnology company Vetagro, in collaboration with Canadian aquaculture CRO Onda, have announced what the businesses say are “compelling” results from a joint research initiative evaluating microencapsulated phytogenics (medicines derived from plants) for their efficacy against Yersinia ruckeri—a major pathogen in rainbow trout farming, which is the cause of enteric redmouth disease in fish.

Two microencapsulated phytogenic feed prototypes demonstrated statistically significant reductions in mortality due to Yersinia ruckeri—by 26.3% and 29.3%, respectively, compared to a control group.

Test feeds showed high acceptance rates among juvenile rainbow trout, confirming both palatability and application feasibility in commercial aquaculture systems.

The results, Vetagro said, reinforce the viability of precision-encapsulated phytogenics as part of a proactive health management strategy for freshwater finfish producers.

The study represents part of a shift toward antibiotic alternatives in aquaculture, showcasing, Vetagro said, the potential of advanced feed additive technologies to mitigate disease and support fish welfare without compromising performance or palatability.

Yersinia ruckeri is a major challenge among producers, causing high mortality rates and reduced growth performance. It is a persistent challenge to rainbow trout producers and makes for complicated disease management due to chronic infections and asymptomatic carriers.

Faced with mounting regulatory pressure and the growing threat of antimicrobial resistance, aquaculture producers worldwide are seeking effective, science-backed alternatives to traditional treatments.

Vetagro’s microencapsulation platform offers a novel solution by protecting sensitive phytogenic compounds until they reach their site of action, thereby preserving their bioactivity and optimizing dosage efficiency.