Practical Diet Includes Low Fish Meal Protein Is Able To Sustain Growth Performance in Gilthead Sea Bream (Sparus aurata, L.;1758) During the Grow-Out Period [Büyütme periyodu boyunca çipuralari{dotless}n (sparus aurata, l.,1758) büyüme performansi{dotless}ni{dotless} saglayacak bali{dotless}k unu orani{dotless}ni{dotless}n belirlenmesine yönelik yem i·çerigi]

Abstract

During 12-week growing trial aimed to evaluate the effects of replacement of fishmeal and fish oil in practical diets for gilthead seabream with a complementary mixture of vegetable proteins (soybean, wheat and corn) and oils (soybean and rapeseed), in terms of growth performance, feed utilization and apparent digestibility of nutrients. Fifteen homogenous groups of 180 sea bream each (mean initial body weight: 190.4±5.4 g) were stocked in 2000-L tanks and fed one of five experimental pelleted diets formulated to be isonitrogenous, isolipidic and isoenergetic. A control diet (Control) was formulated with practical ingredients to contain 49% protein, 20% fat and 24 kJ/g energy. Two other diets were formulated in order to replace 40 and 60% of fish meal by increasing levels of selected plant-protein (PP) ingredients and fish oil (FO) (PP40FO and PP60FO, respectively). Based on these two last diets, two others were formulated in which fish oil was replaced at a 62.5% level by a mixture of soybean and rapeseed oils (Vegetable Oil-VO) (PP40VO and PP60VO). Growth of gilthead seabream, expressed either as weight gain or daily growth index was not significantly affected by the replacement at either 40 or 60% of fishmeal by plant-protein sources. At 40% fishmeal replacement level, the further replacement of 62.5% of fish oil by vegetable oils had no effect on growth performance. However, the replacement of 60% fishmeal and 62.5% replacement of fish oil caused reduction in weight gain slightly, but essentially a significant decrease in feed efficiency (FE). Growth performance of gilthead seabream during grow-out was sustained by a practical diet formulation containing as little as 12% of fish meal protein