Recording feed intake of salmon using Xrays

The purpose of this research is to repeatedly record how much feed individual Atlantic salmon eat and match this with how well they grow. Combining this with genetic information, we can determine how to breed for more feed efficient salmon that would require less feed to grow just as well. Salmon feed contains ingredients from wild capture fisheries and is the largest expense of production, it comprises 50% of the production cost. Breeding for more feed efficient salmon would benefit the environmental footprint of Atlantic salmon farming and improve the profitability. The largest difficulty is measuring how much feed individual Atlantic salmon eat. In the 1980s researchers developed a method of using Xray radiography and small radioopague beads in the feed to measure how much salmon eat. Xrays have greatly improved in the last 40 years to the point where smaller fish can be recorded over very short periods of time out of water. Although the time out of water is greatly reduced to seconds, it still causes the fish some distress to be out of the water. A total of 700 Atlantic salmon freshwater stage (average weight 50 gr) coming from 30 families will be used in the experiment. The salmon will be recorded for feed intake (using Xrays) on three occasions over the entire growth period 120 days. The salmon will be fed standard feed which meets all nutritional requirements with the addition of 1% small glass beads.