치어기 대서양 참다랑어(Thunnus thynnus) 사료 내 틸라피아 가수분해물과 아마인유의 이용성에 관한 연구

Abstract

In Chapter 1, study was conducted to evaluate the supplemental effects of tilapia hydrolysate powder (THP) and linseed oil (LO) in diet for Atlantic bluefin tuna. A control diet was formulated to contain 65% of an enzyme-treated fish meal (EFM) and 3% of DHA oil. The THP diet was formulated to replace whole 65% of EFM with THP. The LO diet was formulated to contain 1% linseed oil and 2% DHA oil instead of 3% DHA oil. In the feeding trial, juvenile bluefin tuna (body weight 1.15 g) were randomly stocked into three experimental tanks (70 tons) and fed the diets for 13 days. Weight gain was the highest in the tuna fed LO diet (519%) followed by EFM (444%) and THP (228%) diets. Survival rate and protein digestibility were similar between EFM and LO groups, but lower in the THP group. Thus, this result indicates that LO can be a good candidate for the replacement of approximately 33% DHA oil, however, THP is not suitable to replace EFM in diets for juvenile bluefin tuna. In Chapter 2, study was conducted to evaluate the appropriate content of sardine fish meal and cod liver oil instead of enzyme-treated fish meal and DHA oil in the diet of Atlantic bluefin tuan. A control diet was formulated as EFM diet same as chapter 1. The FM diet was formulated to replace 50% of enzyme treated fishmeal and 100% of DHA oil and linseed oil. There was no significant difference in growth performance, feed utilization, biological assessment of digestive organs and condition factor. As a result of whole-body proximate composition, there was no difference. However, in fatty acid analysis the content of arachidonic acid, EPA, and DHA in the FM group was significantly higher. Thus, it was confirmed that it is possible to use sardine fish meal and cod liver oil in bluefin tuna diet.