Further clarification of winter energy and protein requirements at the optimum feeding frequency for yellowtail

This is another report from a series of studies aimed at determining the en ergy and protein requirements based on the optimum feeding frequency of yel lowtail during the winter season. Experiments were conducted at Mie and Oit a Prefectures, Japan, employing extruded pellets of known digestible energy (DE) and digestible protein (DP) values. Four groups of fish were fed at f requencies of five, three, two, and one time(s) per week. The most efficien t feed performance was obtained for the feeding frequenecy of three times p er week. The DE and DP requirements calculated based on the feeding rate at this frequency were 38.7 kcaI and 2.8g/kgBW per day (14.3-17.3 degreesC) i n Mie and 30.4 kcal and 2.2 g/kgBW per day (13.8-17.5 degreesC) in Oita, re spectively. The present results and the observations on the changes of the contents in digestive tracts tallied with our previous work, confirming tha t the optimum feeding frequency was three times per week.