Dietary supplementation with tributyrin (TBT), a source of butyric acid, has been shown to improve growth performance and health status when high levels of plant ingredients are included in aquafeeds. Here, we investigated the response of rainbow trout (Oncorhynchus mykiss) to a plant-based diet supplemented with TBT aiming to improve fish performance and welfare. Juvenile rainbow trout (19.0 ± 0.19 g, mean ± S...