DIETARY SUBSTITUTION EFFECT OF TUNA BY-PRODUCT MEAL (TBM) FOR FISH MEAL ON GROWTH PERFORMANCE AND FEED EFFICIENCY OF JUVENILE OLIVE FLOUNDER Paralichthys olivaceus

Dietary substitution effect of tuna by-product meal (TBM) for fish meal on growth and feed efficiency  of juvenile olive flounder was investigated . Sixty five percent fish meal was  included  in the control (Con) diet.  Ten, 20, 30, 40 and 50% fish meal in the Con diet w ere substituted  with tuna byproduct meal, referred to as  the TBM 10, TBM20, TBM30, TBM40 and TBM50 diets, respectively.  Fish were fed with one of the experimental diets twice a day for 8 weeks. The greatest weight gain and specific growth rate  (SGR) were obtained in fish fed the TBM40 diet, followed by the TBM50, TBM30, TBM20, Con and TBM10 diets in that order.  Weight gain, SGR and feed efficiency (FE) of fish fed the TBM40, TBM50 and TBM30 diets were greater than those of fish fed the Con diet. Fifty percent fish meal could be replaced with TBM in juvenile olive flounder when 65% fish meal was included in diet. The greatest growth performance and FE were obtained in fish fed the TBM40 diet substituting 40% fish meal with TBM.

Dietary substitution effect of tuna by-product meal (TBM) for fish meal on growth and feed efficiency  of juvenile olive flounder was investigated .  Sixty five percent  fish meal was  included in the  control (Con) diet.  Ten, 20, 30, 40 and 50% fish meal w ere substituted  with TBM, referred to as the TBM 10, TBM20, TBM30, TBM40 and TBM50, respectively. Fish were fed with one of the experimental diets for 8 weeks.

After 8-week feeding trial, the greatest weight gain , specific growth rate and feed efficiency (FE) were obtained in fish fed the TBM 40  diet, followed by the TBM50, TBM30, TBM20, Con and TBM10 diets, in that order (Table 1) .  In conclusion, fish meal up to 50% could be substituted with TBM in juvenile olive flounder feed when 65% fish meal was included. The greatest improvement in growth performance and FE were obtained in fish fed the TBM40 diet substituting 40% fish meal with TBM.