Dietary Thiamine (Vitamin B1) Requirement of Pacific White Shrimp (Penaeus vannamei)

Abstract

흰다리새우(Penaeus vannamei)의 juvenile 및 post-larvae 성장 단계에서 사료 내 thiamine (비타민 B1)의 요구량을 평가하였다. 두 실험 모두, 어분을 주 단백질원으로 사용한 대조사료(T0)를 사용하였으며 cellulose를 20, 40, 80, 100 mg/kg씩 thiamine hydrochloride로 대체하여 5가지 실험사료를 제작하였다(T20, T40, T60, T80 및 T100). Chapter 1에서는 juvenile P. vannamei의 성장률, 사료 이용성 및 비특이적 면역력에 미치는 영향을 바탕으로 사료 내 thiamine 요구량을 평가하였다. 총 360마리의 새우 (6.03 ± 0.03g)를 24개의 아크릴 수조 (240L)에 실험구 당 4반복으로 무작위 배치하여 58일 동안 1일 6 회(08:00, 10:00, 12:00, 14:00, 16:00 및 18:00) 사료를 공급하였다. 고성능 액체 크로마토그래피로 분석한 실험사료의 thiamine 농도는 T0, T20, T40, T40, T60, T80 및 T100에서 각각 3.2, 20.8, 38.7, 60.2, 80.7 및 108 mg/kg으로 나타났다. T20 사료를 공급한 새우는 T0와 T100 사료를 공급한 새우에 비해 유의적으로 높은 성장률을 보였다. Feed conversion ratio (FCR)과 protein efficiency ratio (PER)는 모든 실험구 간에 유의적인 차이가 없었다. T20구는 T0구 및 T100구보다 유의적으로 높은 phenoloxidase (PO) 활성도를 보였다. Lysozyme 활성도는 T20, T40, T60, T80구에서 T0구에 비해 유의적으로 향상되었다. Anti-protease 활성도는 사료 내 thiamine 농도에 영향을 받지 않았다. Superoxide dismutase (SOD)와 glutathione peroxidase (GPX) 활성도는 T20구에서 T0에 비해 유의적으로 향상되었다. Penaiedin 3a와 insulin-like growth factor-1 (IGF-1)의 유전자 발현량은 사료 내 thiamine 농도에 영향을 받지 않았다. T20 및 T40 사료를 공급한 새우는 T0 사료를 공급한 새우보다 유의적으로 높은 prophenoloxidase (proPO) 발현량을 보였다. Hemolymph 내 glucose, total cholesterol, triglycerides 및 total protein 수준은 모든 실험구에서 유의적인 차이가 없었다. 장 내 융모 길이는 사료 내 thiamine 농도에 영향을 받지 않았다. Juvenile P. vannamei의 사료 내 최적 thiamine 농도는 weight gain (WG)을 바탕으로 한 piecewise regression 분석 결과, 19.7 mg/kg 일 것으로 판단된다. Chapter 2에서는 post-larvae P. vannamei의 성장률, 사료 이용성, 비특이적 면역력, 소화효소 활성도 및 암모니아 스트레스 내성을 바탕으로 사료 내 thiamine 요구량을 평가하였다. 총 1,200마리의 새우(5 mg)를 24개의 아크릴 수조(10L)에 실험구 당 4반복으로 무작위 배치하여 30일 동안 1일 6회 사료를 공급하였다(08:00, 10:00, 12:00, 14:00, 16:00 및 18:00). 고성능 액체 크로마토그래피로 분석한 실험사료의 thiamine 농도는 T0, T20, T40, T60, T80 및 T100에서 각각 6.1, 28.5, 48.1, 73.3, 85.7 및 106 mg/kg으로 나타났다. 사육실험 후, 실험구 당 60마리(수조 당 15마리)의 새우를 무작위로 포획하여 암모니아 공격실험을 위해 3반복으로 배치하였다. 모든 thiamine 첨가구는 T0구에 비해 성장률과 사료 이용성이 유의적으로 높았다. T40, T60, T80 및 T100구의 final body weight은 T0구에 비해 유의적으로 높았고 WG와 specific growth rate도 유사한 경향을 보였다. Feed conversion ratio는 T40, T60, T80 및 T100구에서 T0구에 비해 유의적으로 향상되었으며 protein efficiency ratio는 모든 thiamine 첨가구에서 T0구에 비해 유의적으로 높았다. 생존율은 모든 실험구 간에 유의적인 차이가 없었다. 새우의 소화 효소(amylase, lipase 및 pepsin) 활성도는 사료 내 thiamine 농도가 높을수록 향상되었으며 T0구에 비해 유의적으로 높았다. 모든 thiamine 첨가구에서 T0구에 비해 유의적으로 높은 IGF-1, insulin-like growth factor binding protein (IGF-BP), proPO 및 crustin 발현량이 나타났다. 암모니아 침지 48시간 후, 새우의 생존율은 T80구에서 T0구에 비해 유의적으로 높았다. Post-larvae P. vannamei의 사료 내 최적 thiamine 농도는 WG를 바탕으로 한 piecewise regression 분석 결과, 72.9 mg/kg일 것으로 판단된다.|Present two studies investigated the dietary thiamine (vitamin B1) requirement of Pacific white shrimp (Penaeus vannamei) at two different stages of their life cycle. For both experiments, a fish meal based basal diet (T0) was formulated and five other test diets were formulated by incorporating thiamine hydrochloride at graded levels of 20, 40 60, 80 and 100 mg/kg of diet, at the expense of cellulose (designated as T0, T20, T40, T60, T80, and T100). Chapter 1 investigated the dietary thiamine (vitamin B1) requirement of juvenile P. vannamei and its effects on growth performance, feed utilization, innate immunity, and intestinal histomorphology. A Total of 360 shrimp (6.03 ± 0.03 g) were randomly assigned into 24 acryl tanks (240 L) to be quadruplicated per treatment, and feeding was done in six equal portions daily for 58 days. High-performance liquid chromatography of the test diets revealed that the thiamine concentration of T0, T20, T40, T60, T80, and T100 experimental diets at 3.32, 20.8, 38.7, 60.2, 80.7, and 108 mg/kg of diet respectively. The T20 diet fed group exhibited significantly higher growth performance compared to shrimp fed T0 and T100 diets. Feed conversion ratio (FCR) and protein efficiency ratio (PER) were not significantly different among experimental groups. A significantly higher phenoloxidase activity was exhibited in T20 dietary group than T0 and T100 groups. Lysozyme activity was significantly enhanced in T20, T40, T60, and T80 groups than in T0 group and antiprotease activity was not significantly affected. Antioxidant parameters: superoxide dismutase activity (SOD) and glutathione peroxidase (GPx) activities were significantly elevated in T20 dietary treatment group. Significantly upregulated proPO gene expression was observed in T20 and T40 dietary treatment groups, although penaiedin 3a and insulin-like growth factor-1 (IGF-1) relative gene expressions were not significantly different. Glucose, total cholesterol, triglyceride, and total protein levels in hemolymph were not significantly different. Intestinal histology observations did not show significant differences in villi heights. A piecewise regression of weight gain percentage (WG%) estimates the optimal dietary thiamine requirement of P. vannamei at 19.7 mg/kg of diet. Chapter 2 investigated the dietary thiamine (vitamin B1) requirement of post larvae P. vannamei and its effects on growth performance, feed utilization, innate immunity, digestive enzyme activity and ammonia stress tolerance. High-performance liquid chromatography of the test diets revealed that the thiamine concentration of T0, T20, T40, T60, T80, and T100 experimental diets at 6.14, 28.5, 48.1, 73.3, 85.7 and 106 mg/kg of diet, respectively. A total of 1200 P. vannamei post larvae (5 mg) were randomly distributed into 24 acryl tanks (50 shrimp/tank, 10 L) with four replicates per treatment. Daily feed requirement was divided into six equal portions and the feeding was done at 08:00, 10:00, 12:00, 14:00, 16:00, and 18:00 h for 30 days. After the feeding trial, 60 shrimp from each dietary treatment were captured, pooled and redistributed into three replicate tanks (10 L) for the ammonia stress challenge test. Thiamine supplemented groups showed a significant improvement in growth performance and feed utilization. Final body weight of T40, T60, T80 and T100 dietary groups were significantly higher compared to the T0 group and both WG% and specific growth rate followed a similar trend. Significant enhancements in FCR were observed in T40, T60, T80 and T100 groups and PER was significantly elevated in thiamine supplemented groups (T60, T80, T100) compared to the thiamine deficient group (T0). Survival percentage was not significantly different among the experimental groups. Thiamine supplementation significantly enhanced the activity of digestive enzymes (amylase, lipase, pepsin) and the significantly lowest activities were observed in T0 group. Compared to the thiamine deficient group, relative gene expression of IGF-1, insulin like growth factor binding protein (IGF-BP) gene expressions were significantly upregulated in thiamine supplemented groups. Antioxidative gene expressions (catalase, SOD, GPx) were significantly upregulated through thiamine supplementation. Similarly innate immune related genes (proPO, crustin) were significantly expressed in thiamine supplemented groups. In the challenge test, after 48 h, a significantly higher survival rate was observed in T80 dietary group while thiamine deficient group manifested the significantly lowest survival. A broken line regression of WG% estimated the dietary thiamine requirement of P. vannamei post larvae at 72.9 mg/kg of diet.