Optimum Dietary Ratio of Raw Fish and Commercial Compound Meal in Moist Pellet for Flounder (Paralichthys olivaceus)

Dietary optimum ratio of frozen raw fish and commercial compound meal (CCM) in moist pellet (MP) were investigated to improve the growth rate, and feed and economical efficiency in the flounder, Paralichthys olivaceus. Experimental fish (average body weight, about 48 g) were divided into 6 groups and each group was fed with raw fish (FRF), and MPs (ratio of raw fish and CCM=9:1, 8:2, 7:3, 6:4 and 5:5) for 10 weeks. The 9:1, 8:2, 7:3, 6:4, 5:5 groups showed no significant difference in weight gain as 203.5~217.3%, while the FRF group showed significantly low growth rate as 183.1%(P<0.05). The feed efficiency gradually increased with the increase in the ratio of CCM and was the highest in the 5:5 group as 89.7%. As a result of analysis of body composition after the experiment, moisture was significantly low in the 7:3 group (P<0.05) and crude protein was significantly low in the 9:1 group (P<0.05). The crude lipid increased as the ratio of raw fish increased, and it was the highest in the raw fish group (8.3%) and the lowest in the 5:5 group (4.6%). There were no significant difference in hepatosomatic index (HSI) and condition factor(CF) among the experimental groups. Visceralsomatic index (VSI) increased with the increase in the ratio of raw fish and was significantly high in the raw fish group as 5.49 (P<0.05). For the unit cost of feed, it was found that raw fish was economical when mackerel, a source of raw feed, was 400 won/kg, while the ratio of 5:5 was economical when it was more than 500 won/kg. Results of this study concluded that sole use of raw feed is not desirable in view of growth, environment and economy, and the 5:5 group showed highest effect under the least use of raw feed.

넙치용 습사료에 있어서 생사료와 분말배합사료의 적정 혼합비

양식현장에서의 효율적인 생사료 사용을 위해 경제적이며, 성장효과가 뛰어난 생사료와 분말배합사료의 적정 혼합비를 구명하고자 넙치(평균체중 48g)를 대상으로 사육실험을 실시하였다. 생사료 단독구(FRF)를 대조구로 설정하였으며, 생사료와 분말배합사료의 배합비율은 9:1, 8:2, 7:3, 6:4 및 5:5로 설정하였다. 10주간 사육실험 결과, 성장률은 9:1, 8:2, 7:3, 6:4 및 5:5 구는 203.5~217.3%로 유의적인 차이가 없었으나, FRF구는 183.1%로 유의적으로 낮은 성장을 나타냈다(P<0.05). 사료효율은 분말배합사료의 비율이 증가함에 따라 점차 증가하여 5:5 구가 89.7%로 가장 높았다. 실험 종료 후 어체 분석 결과, 수분은 7:3구가 유의적으로 낮았으며(P<0.05), 조단백질은 9:1구가 유의적으로 낮았다(P< 0.05). 조지방 함량은 생사료의 비율이 증가할수록 증가하여 FRF구가 8.3%로 가장 높았으며, 5:5구가 4.6%로 가장 낮았다. 간중량지수(HSI)와 비만도(CF)는 실험구간의 유의적인 차이가 없었으며, 내장중량지수(VSI)는 생사료 비율이 증가할수록 높아져 생사료가 5.49로 유의적으로 높은 값을 나타냈다(P<0.05). 사료단가에서는 생사료원인 고등어가 400원/kg 일때는 생사료가 경제적인 것으로 나타났으나 500원/kg 이상일 때는 5:5가 경제적인 것으로 나타났다. 본 연구결과, 생사료의 일방적인 사용은 성장, 환경 및 경제적 측면에서 바람직하지 못하며, 5:5구가 생사료의 최소한의 사용으로 높은 효과를 나타내었다.