Seasonal high protein diets for arctic salmon

Offentlig prosjektsammendrag

One main challenge of farming in the Arctic regions is the low temperature and consequently lower growth. Therefore, it is important to maximize salmon growth through optimized feeds, which are optimized to the varying seasonal growth conditions. Today, commercial diets for farmed Atlantic salmon contain 30-35% protein and 35-39% lipids. Such energy dense diets have shown to improve feed utilization and growth. However, reducing the dietary protein to lipid ratio may lead to increased deposition of fat in the muscle and visceral cavity. Thus, there is a risk of lowered growth during periods with increased feed intake and high fat accumulation when feeding high-fat diets. In addition, the product and slaughter quality are important criteria for evaluation of the optimum protein/energy ratio. An earlier study at Arctis Salmon Research Centre (RCN 277964 NutriOptimal) showed a higher growth rate of salmon fed with a higher protein diet during winter, however, this higher protein level was confounded with a higher energy level in the feed. Hence, it is needed to study if an increased protein/energy level will increase the salmon growth rate during the arctic winter. Besides, we have observed unexpected low growth rates during the spring period, so it is of interest to see if a prolonged period of feeding high protein/energy ratio can support extra growth during spring in Finnmark. The aim of this project is to test if seasonal increases in dietary protein/energy level can increase fish performance, health and harvest quality in salmon farmed in the Artic environment.