The effects of supplementing ESP-FM (Erythrobactor sp.), freshwater Chlorella (Chlorella sp.), and baker’s yeast (Saccharomyces cerevisiae) on the nutritional value and mass production of Moina macrocopa, which is used as a live feed for fish fry production, was investigated. Consequently, the effects of feeding the enriched M. macrocopa to the nutritional composition of larval rockfish (Sebastes schlegel) and carp (Cyprinus carpio) was also investigated. Maximum density of M. macrocopa was reached within 15-21 days after inoculation (0.5 to 22 individual/mL), at various temperatures, and either decreased or remained almost constantly thereafter. Protein content and amino acids composition of M. macrocopa were found to be influenced by their respective diets while lipid and ash contents did not considerably change. M. macrocopa fed with baker’s yeast were low in n-3 HUFA content, and those fed on the freshwater chlorella were high in the 18:2n-6 and 18:3n-3 HUFA content, and in cultures treated with ESP-FM were high content in n-3 HUFA. The utilization of M. macrocopa as a substitute fish feed for carp and rockfish showed the enrichment nutritional content.

The aim of this study was to determine the effects of different soy protein concentrate (0, 15, 30, and 45%), defatted soy flour (0, 10, 20, and 30%), and wheat flour (10, 20, and 30%) contents replacing fish meal on physiochemical properties of extruded aquatic feed by using a twin screw extruder. The moisture content, barrel temperature, die diameter, and screw speed were adjusted to 45%, 137oC, 4 mm, and 250 rpm, respectively. With the higher amount of soy protein concentrate replacing fish meal, the expansion ratio, swelling ratio, and water stability increased significantly while specific length and water holding capacity decreased significantly. With the increasing defatted soy flour content, expansion ratio increased significantly, but specific length, water holding capacity and water stability decreased significantly. With increase in the wheat flour content, the specific length significantly decreased while the water stability significantly increased. In conclusion, aquatic feed quality was optimized in this study and could be used in the future.

The aim of the study was to determine physiochemical properties of extruded fish feed at different barrel temperature (120, 130, and 140°C) and moisture content (35, 40, and 45%). As barrel temperature and moisture content increased, expansion ratio, water holding capacity, and water stability increased, while bulk density, hardness, and swelling ratio decreased. Soaking time had significant (P<0.05) effect on water stability. Best water stability was observed on all samples soaked for 1 h. Protein digestibility was not significantly different among the samples while protein digestibility of extruded fish feed significant higher than raw materials.

근해의 어족자원 고갈 및 수질오염은 수산양식 산업에 큰 영향을 미친다. 이러한 문제점을 해결하기 위하여 근해에서 외해로 양식장이 이동하고 있다. 외해 양식장은 근해보다 해상환경에 강인하게 개발되어야 하며, 안정적인 양식장 운영을 위해 원격 자동먹이 공급장치가 필요하다. 본 논문은 해상의 양식장에 적합한 원격 먹이공급시스템에 관하여 기술하고자 한다. 어류는 수온 및 어체 중량에 따라 먹이를 먹는 양이 변화한다. 해상 양식장의 경우 육상에 비하여 온도 변화가 크게 일어난다. 본 논문은 수온 및 어체 중량에 따라 먹이량을 계산하고 자동으로 먹이를 공급하는 시스템을 연구하였다. 모형을 활용한 먹이 공급 장치의 성능을 실험하였다.

근해의 수질오염은 수산양식 산업에 큰 영향을 미친다. 이러한 문제점을 해결하기 위하여 근해에서 외해로 양식장이 이동하고 있다. 외해 양식장의 구축을 위해서는 자동먹이 공급장치 및 원격 관리 시스템이 필요하다. 본 논문은 해상의 양식장에서의 자동 먹이 공급 시스템에 관하여 설명하고자 한다. 어류는 수온 및 어체 중량에 따라 먹이를 먹는 양이 변화하며, 해상 양식장의 경우 육상에 비하여 온도 변화가 크게 일어난다. 본 논문은 수온 및 어체 중량에 따라 먹이량을 계산하고 자동으로 먹이를 공급하는 시스템을 연구하였으며 모형 실험을 통하여 먹이 공급 장치의 성능을 검증하였다.