Browsing by Author "Manabu Ishikawa"

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    Can canola meal and soybean meal be used as major dietary protein sources for kuruma shrimp, Marsupenaeus japonicus?
    (Aquaculture, 2015-10-31) Mahbuba Bulbul; Md. Abdul Kader; Md. Asaduzzaman; Mohd. Azmi Ambak; Ahmed Jalal Khan Chowdhury; Md. Sakhawat Hossain; Manabu Ishikawa; Shunsuke Koshio
    A feeding trial was conducted to utilize canola meal and soybean meal as major dietary protein sources for kuruma shrimp, Marsupenaeus japonicus. Four isocaloric diets (19 kJ g−1) were formulated by reducing 0 (FM40), 70 (FM12), 85 (FM6) and 100% (FM0) of dietary fishmeal with a combination (4:6) of canola meal and soybean meal (blend). Based on a series of previous studies, all the plant protein diets (FM12, FM6 and FM0) were supplemented with 1.00% lysine, 0.50% methionine, 0.04% phytase and varying levels of fish soluble to improve the nutritional quality of the diets. Fifteen shrimp with an initial average weight of 1.74 g were randomly stocked in 12, 54 l rectangular tanks in triplicate per dietary treatments. The shrimpwere given the respective test diets daily by hand at 8–10% of bodyweight for 60 days. Final bodyweight (g) and specific growth rate (% day−1) were not significantly (P N 0.05) affected by reducing fishmeal with plant protein blend. Feed intake was also not varied among the dietary treatments. On the other hand, feed conversion ratio was significantly (P b 0.05) increased in the FM0 group, while no difference was found among the rests. Protein efficiency ratio had an opposite trend and the FM0 group demonstrated significantly lowest value. Similarly, protein gain (g kg weight gain−1) and protein retention (%) were significantly decreased in the FM0 group. Dietary treatments had no negative effects (P N 0.05) on the whole body composition. Significant effect was also not found on the protease activity (unit mg−1 protein) in the digestive tract of shrimp fed the FM40, FM12 and FM6 diets, while the value was significantly decreased in shrimp fed the FM0 diet. The values for the total hemocyte count (cellsml−1) and viable cells (%)were lowest in the FM0 group, however these parameterswere not significantly varied among the dietary treatments. Upon considering the results obtained in the present experimental condition, it has been concluded that canolameal and soybean meal could be effectively utilized as major protein sources by kuruma shrimp. The dietary fishmeal could be reduced to only 6% (85% replacement) with a blend of canola meal and soybean meal, and supplementation of methionine, lysine, phytase and fish soluble without compromising growth, feed utilization, body composition and health of juvenile kuruma shrimp. Statement of relevance: The research findings will help to develop plant protein based diets for crustaceans
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    Efficacy of nucleotide related products on growth, blood chemistry, oxidative stress and growth factor gene expression of juvenile red sea bream, Pagrus major
    (Aquaculture, 2016) Md. Sakhawat Hossain; Shunsuke Koshio; Manabu Ishikawa; Saichiro Yokoyama; Nadia Mahjabin Sony; Mahmoud A.O. Dawood; Md. Abdul Kader; Mahbuba Bulbul; Takeshi Fujieda
    A feeding trial was conducted to determine the efficacy of nucleotide related products on growth, blood chemistry, oxidative stress and growth factor gene expression of juvenile red sea bream. Five experimental diets were formulated to contain 49% protein, 11% lipid and the diet without nucleotide related product supplementation was the control (D1). Nucleotide related products like; nucleoside by-products (NBPs) and inosine were supplemented at 1, 3 and 0.03, 0.1% consecutively with basal ingredients of D1 and named as D2, D3 & D4 and D5 respectively. Experimental diets were fed to triplicate groups of fish for 60 days. Fish fed diet D5 showed significantly the highest final bodyweight and %weight gain followed by the diet groups D2 and D4. Fish fed control group showed the lowest growth performance and were not differed significantly with diet group D3. Feed conversion ratio and protein efficiency ratio were also significantly higher in diet group D5, whereas the other supplemented group showed intermediate value. A wide variation in some of the blood parameters was observed. In case of oxidative stress parameters, fish fed inosine supplemented diets showed the best conditions because they performed better under oxidative stress conditions as well as had the highest tolerance against oxidation.AmongNBP supplemented groups, diet group D2 also showed acceptable conditions of oxidative stress tolerance. Stress resistance against lowsalinity exposure (LT50) also increasedwith dietary supplementation and it was significantly the highest in fish fed diet group D5. Total serum protein, serum lysozyme activity and total peroxidase content tended to be higher (P N 0.05) in NBP and inosine supplemented diet groups. In numerically higher hepatic IGF-1, mRNA expression was found in diet groups D2 and D4. However, IGF-1 and IGF-2 mRNA expressions were not significantly altered by dietary supplementations in the present study. Considering overall performance of the present study, we concluded that inosine and low concentration of NBP (1%) could be effectively used as dietary supplements for better growth and health performance of Pagrus major. Statement of relevance: In this study industrial by-products, nucleoside by-products and relatively lowcost nucleoside, inosine has been evaluated as potential functional nutrients for marine fish such as red sea bream. Utilization of these functional supplements will help to reduce nucleotide administration cost in fish feed as well as to develop low fishmeal based functional aquafeed in the near future.