배합사료와 생사료의 급이가 미성어기 넙치(Paralichthys olivaceus)의 소화생리에 미치는 영향

Abstract

The olive flounder is considered an important aquaculture species due to its rapid growth capacity. In Korea, juvenile olive flounder were usually fed to raw-based feed or moist pellet (MP), However feeding management described various opinion in published work and the lack of a standardized feeding scheme. In addition, most of the studies differ to contradicting results due to the growth. This study aimed to analyze the effects of the moist pellet (MP) and extruded pellet (EP) diet on the growth performance, level and expression of the growth factors (GH/IGF axis), digestive physiological characteristics of the sub-adult olive flounder reared on an actual aquaculture field farm. MP was a raw fish-based diet composed of mackerel and cutlass fish and EP diet was a commerical feed (Suhyup Feed, Korea). Results showed that the growth performance was statisticallly better when given EP diet and feed conversion ratio and condition factor was similarily EP and MP diet. Plasma level of growth hormone and insulin-like growth factor 1 was comparably similar between diets, however, the hepatic IGF-1 gene expression is higher in extruded pellet-fed fish. The intestinal villi and goblet cells count were significantly longer and more numerous in EP-fed on the olive flounder. When comparing the extruded pellet and raw-based pellet, the activity of trypsin, chymotrypsin, and lipase were no difference in the experimental group as the growth stage increased. Based on the current results EP has the it is concluded that the growth performance significant higher than extruded pellet for moist pellet, and it is feasible to substitute the feed with a raw-based feed for Sub-adult fish in actual farm conditions based on long-term field application.