What are the mechanisms behind negative effects of vaccination on growth in fish?

The aim is to contribute to economically, ethically and environmentally sustainable fish aquaculture through more effective vaccination methods with decreased side effects, and that promote animal welfare. We will clarify the physiological causes for  negative effects of vaccination on growth in rainbow trout.

Impaired fish growth means a greater cost to the farmers and the environment if feed is underutilized, and is a suboptimal use of resources.

Rainbow trout in Sweden often recieve a vaccine that contains antigens and mineral oil as adjuvant, which stimulates the immune system chronically. With vaccinated fish as a model, we will test the hypothesis that there is an immune function-growth trade off.

In dialogue with farmers, we will perform a series of experiments; we will study growth and feed utilization and underlying physiological mechanisms such as oxygen consumption, nutritent uptake, appetite and growth endocrinology.

The reserach is relevant for SDG2, calling for an increased production of nutritious food,at the same time as other SDGs need to be reached with targets to mitigate declines in wild fish, and responsible production and consumption.

To attain these, food production systems are becoming more and more intensive, and in aquaculture there is a shift towards closed/semiclosed systems and therefore we need to adopt safe, efficient production practices that benefit both the farmers, the environment and safeguard the health and welfare of the animals.