A new type of fish diet, non-fish meal extruded pellet for yellowtail, Seriola quinqueradiata

A non-fish meal diet using plant and/or animal protein materials for yellowtail, Seriola quinqueradiata was developed. Three kinds of non-fish meal diets and a control diet containing 50% fish meal were processed. In the non-fish meal diets, the fish meal was replaced with commercially available plant or animal materials and supplemented with taurine and other ingredients for maintaining palatability. These diets were fed to one year old yellowtail (body weight: 753±96 g) in net cages. No significant differences in growth, daily weight gain, daily feed rate, feed conversion ratio and protein efficiency ratio were observed among fish given the diets. Non-fish meal diets were processed in a factory and their biological characteristics were studied such as uptake, stomach evacuation rate, and disease resistance. In addition, the diet palatability of each substitute protein source for fish was examined and ingredients that enhanced palatability of the non-fish meal diets were identified. Non-fish meal diets have the potential to support the growth of one year old yellowtail.