Growth and Whole-body Lipid Content of Juvenile Red Sea Bream Reared under Different Conditions of Exercise Training and Dietary Lipid

Abstract

Two experiments were conducted to determine the effect of continuous exercise training, dietary lipid, and starvation on the growth and efficiency of feed utilization of red sea bream Pagrus major. In the first experiment, fish (2.5g) were maintained in water velocities of 0, 1.5, and 3 body lengths per second (BL/s) under satiation feeding. In the second experiment, fish (17.5g) were maintained at 0, 1, and 2 BL/s under a restricted feeding regime. The fish in both experiments were feddiets containing two levels of lipid, and after the feeding period, the fish were fasted for seven days under exercise conditions. In the first experiment, higher swimming speed negatively affected the final body weight and specific growth rate, but not feed efficiency or nitrogen retention. In the second experiment, the non-exercised fish exhibited higher feed efficiency and nitrogen retention, as well as growth rate, than did the exercised fish. The whole-body lipid content was reduced by fasting and by increased exercise, but was positively related to dietary lipid level. Swimming activity level exerted a greater effecton whole-body lipid level than either dietary lipid level or starvation.