Effects of solid state fermented plant protein sources as fish meal replacers in whiteleg shrimp Litopaeneus vannamei

Abstract

본 연구는 치하기 흰다리새우 (Litopaeneus vannamei) 사료 내 식물 단백질원과 바실러스 균의 고체 발효공정처리를 통한 어분대체 효과를 평가하기 위하여 수행하였다. 실험 1에서는, 어분대체를 하지 않은 대조구 (Fishmeal, CON), 발효대두박과 바실러스균 (FSMB), 멸균처리한 FSMB (FSMBS), 발효대두박, 콘글루텐밀 및 바실러스균 (FSCB), 멸균처리한 FSCB (FSCBS), 발효 농축콩단백과 바실러스균 (FSPB), 발효대두박과 유산균 (FSML), 농축대두단백 (SPC) 로 7개의 어분대체구를 설계하여 각각 30%의 어분대체를 실시하였다. 증체율 (weight gain)과 일간성장률 (specific growth rate)에 있어서 FSMB 와 FSCB 구가 CON과 FSML 구에 비해 유의적으로 높은 값을 나타냈다 (P<0.05). Lysozyme 활성은 FSCB 구가 CON과 FSML 구에 비해 유의적으로 높은 값을 나타냈다 (P<0.05). 반면에, 공격실험 8일차에서는 FSCB 구가 타 실험구에 비해 유의적으로 높았다(P<0.05). 실험 2에서는, 수질개선 평가를 위해 실험 1에서 사용된 총 4개의 실험사료 (CON, FSMB, FSCB, FSPB) 에 상업용 수질정화제 (AquaStar®) 를 사육수에 첨가 (O) 또는 무첨가 (X) 하여 무첨가구: CON (X), FSMB (X), FSCB (X) 및 FSPB (X) 와 첨가구: CON (O), FSMB (O), FSCB (O) 및 FSPB (O), 총 8개의 실험구로 설계하였다. 총 암모니아질소(TAN) 농도에서 FSCB(O) 과 FSPB(O) 구가 CON (X) 에 비해 유의적으로 낮은 값을 나타내었다. (P<0.05). Bacillus count (BSC) 분석결과 2주와 4주 후, CON(O) 과 CON(X) 구는 타 실험구에 비해 균 수가 유의적으로 낮은 결과를 나타났다 (P<0.05). 따라서, 본 연구결과를 통해 치어기 흰다리새우 사료 내 발효대두박, 콘글루텐밀 및 바실러스균 (FSCB) 실험구는 어분대체재로써 성장 및 면역 상승효과를 나타낼 뿐만 아니라 수질개선에도 효과가 있다고 판단된다.

Two feeding trials were conducted to evaluate effects of different types of solid state fermented plant protein sources with Bacillus spp. as fish meal replacers in juvenile whiteleg shrimp, Litopaeneus vannamei. In the first trial, a control diet with no replacement for fish meal (CON) and seven other diets that replaced 30% of fish meal with fermented soybean meal with Bacillus spp. (FSMB), sterilized FSMB (FSMBS), fermented soybean meal and corn gluten meal with Bacillus spp. (FSCB), sterilized FSCB (FSCBS), fermented soy protein concentrate with Bacillus spp. (FSPB), fermented soybean meal with lactic acid bacteria (FSML), and soy protein concentrate (SPC) were used. Results showed significantly higher weight gain and specific growth rate for shrimp fed the FSMB and FSCB diets comparing to those of shrimp fed the CON and FSML diets (P<0.05). Lysozyme activity of shrimp fed the FSCB diet was higher than those of shrimp fed CON and FSML diets. After eight days of challenge test, shrimp fed the FSCB diet showed higher survival compared to shrimp fed all the other diets (P<0.05). In the second trial, the effects of fermented plant proteins with or without bacterial water treatment was determined on water quality indices of whiteleg shrimp culture. Juvenile whiteleg shrimp were fed by the CON, FSMB, FSCB and FSPB diets. All treatments were divided into two groups, one group with the addition of bacterial water treatment (AquaStar®) and one group without bacterial water treatment (assigned as O and X, respectively). Results for total ammonia nitrogen showed significantly lower values for FSCB(O) and FSPB(O) tanks compared to the CON(X) tanks (P˂0.05). Same trend was observed for NO2-N as CON(X) tanks had significantly higher values. Total Bacillus spp. counts, after 2 and 4 weeks, were significantly lower for both CON(O) and CON(X) tanks compared to all other tanks (P˂0.05). Based on these results, replacement of fish meal with Bacillus-fermented soybean meal and corn gluten meal (FSCB) can improve growth, feed utilization, immune response and disease resistance in whiteleg shrimp while improving the water quality indices when administered with bacterial water treatment.