Effect of dietary pigment on growth performance and disease resistance in black tiger shrimp post larva (Penaeus monodon, Fabricius)

Effects of dietary pigment on survival and disease (white spot syndrome virus: WSSV) resistance in black tiger shrimp post larva (Penaeus monodon, Fabricius) (PL15) for a 30-day period were studied. The results showed that not only was mean survival of black tiger shrimp (PL15) fed with supplementation of Lucarotene or Betatene at 125 mg/kg diet significantly higher (P<0.05) but also the body color was increased. There were no effects of dietary pigment on mean weight, percent weight gain and WSSV resistance. However, mean WSSV resistance of black tiger shrimp (PL15) fed diet containing Lucantin pink 50 mg/kg diet, Spirulina 30 g/kg diet or Betatene 125 mg/kg diet was higher than that of control

Effects of Thai medicinal plants on pathogenic bacterial, growth performance, health condition and disease resistance in black tiger shrimp (Penaeus monodon Fabricius)

Chemical analysis of turmeric (Curcuma longa) extracts using TLC/densitometry, showed an extract contain 21.57%w/w of three important curcuminoids: curcumin, desmethoxycurcumin and bisdesmethoxycurcumin. GC and MS were used to analyze volatile oils. Aromatic turmerone, α-turmerone and zingiberene were also obtained. Qualitative and quantitative analyses alcoholic extract of Andrographis paniculata using TLC, revealed that the extracts contain three important compounds in total lactone of 30.49% w/w. There are andrographolide,14-deoxy-11-12-didehydroandrographolide and neoandrographolide. TLC-chromatogram of Clinacanthus nutans extract after reacted with anisaldehyde/sulfuric acid showed a 9 key compounds, while preliminary neutralization test of the compounds revealed that there were active compounds against HSV-1 virus. In vitro efficacy test revealed that Curcuma longa and Andrographis paniculata extracts at 250 and 1,500 mg/L could eradicate 15 isolates of Vibrio spp. which were isolated from infected shrimps. Effects of medicinal plant extracts incorporated into the diet on shrimp immune responses were investigated. Shrimp fed diet containing Clinacanthus nutans extract at 20 mg/kg of diet had good growth, FCR and immune responses. The shrimp that were fed diet containing Curcuma longa extracts at 25 mg/kg of diet for 7-14 days showed high resistance to Vibrio harveyi. Likewise, the shrimp fed Andrographis paniculata extract at 25 mg/ kg of diet for 14 days had a higher resistance to WSSV. Incorporating the medicinal extracts at higher levels resulted in reduction in diet palatability which consequently had an effect on a decrease in growth, immune responses and resistance to bacterial and WSSV infection

Efficacy of insect larval meal to replace fish meal in juvenile barramundi, Lates calcarifer reared in freshwater

The present experiment was conducted to evaluate the efficacy of dietary protein from black soldier fly, Hermetia illucens, larval meal (BSFL) to replace fish meal (FM) protein in juvenile barramundi, Lates calcarifer. Larvae of black soldier fly were fed with the underutilised crop, sesbania, Sesbania grandiflora. Five isonitrogenous (44% crude protein) and isocaloric (16.0 kJ available energy/g) experimental diets were formulated to replace FM using processed BSFL meal at 0 (control), 25% (BSFL25), 50% (BSFL50), 75% (BSFL75) and 100% (BSFL100). Data for proximate and amino acid analysis suggested BSFL meal as an inferior protein ingredient than FM, but parallel to soybean meal. At the end of 8 weeks of fish feeding trial, there were no significant differences in the average weight gain (WG) and specific growth rate among the group of fish-fed control, BSFL25 and BSFL50 diets (P < 0.05). Although numerical differences were recorded in the fish whole-body proximate composition, crude protein and moisture content were not much affected by the different dietary treatments. Essential amino acids including arginine, histidine, lysine and methionine were found to be higher in the whole body of fish-fed BSFL100 diet. Broken line regression analysis of average WG showed an optimum FM replacement level of 28.4% with BSFL meal. Therefore, the present experiment clearly demonstrates that the maximal dietary inclusion level of BSFL meal as FM protein replacer for the optimum growth of juvenile barramundi reared in freshwater could be greater than 28.4% but less than 50%, without any adverse effects on the fish whole-body proximate and amino acid composition

Investigation of highly unsaturated fatty acid metabolism in the Asian sea bass, Lates calcarifer

Lates calcarifer, commonly known as the Asian sea bass or barramundi, is an interesting species that has great aquaculture potential in Asia including Malaysia and also Australia. We have investigated essential fatty acid metabolism in this species, focusing on the endogenous highly unsaturated fatty acid (HUFA) synthesis pathway using both biochemical and molecular biological approaches. Fatty acyl desaturase (Fad) and elongase (Elovl) cDNAs were cloned and functional characterization identified them as ∆6 Fad and Elovl5 elongase enzymes, respectively. The ∆6 Fad was equally active towards 18:3n-3 and 18:2n-6, and Elovl5 exhibited elongation activity for C18-20 and C20-22 elongation and a trace of C22-24 activity. The tissue profile of gene expression for ∆6 fad and elovl5 genes, showed brain to have the highest expression of both genes compared to all other tissues. The results of tissue fatty acid analysis showed that the brain contained more docosahexaenoic acid (DHA, 22:6n-3) than flesh, liver and intestine. The HUFA synthesis activity in isolated hepatocytes and enterocytes using [1-14C]18:3n-3 as substrate was very low with the only desaturated product detected being 18:4n-3. These findings indicate that L. calcarifer display an essential fatty acid pattern similar to other marine fish in that they appear unable to synthesize HUFA from C18 substrates. High expression of ∆6 fad and elovl5 genes in brain may indicate a role for these enzymes in maintaining high DHA levels in neural tissues through conversion of 20:5n-3

Effects of carotenoid sources on growth performance, blood parameters, disease resistance and stress tolerance in black tiger shrimp (Penaeus monodon Fabricius)

Two feeding trial were conducted to determine the effects of various sources of carotenoid on growth performance, disease resistance, blood parameters, stress tolerance and pigmentation in juvenile black tiger shrimp (Penaeus monodon). Trial I was performed in small shrimp (1 g average body weight). The shrimp were fed with control diet without carotenoid (diet 1) while diets 2 to 6 contained 50 mg/kg astaxanthin (Lucanthin Pink®), 125 mg/kg β-carotene (Lucarotin®), 200 mg/kg β-carotene (Lucarotin®), 125 mg/kg Betatene® extracted from Dunaliella and 3% dried Spirulina respectively. There was an improvement in color in all groups of shrimp fed caroteniod supplemented diets, but no significant differences in weight gain or survival among the shrimps fed each test diet (p>0.05). Resistance to white spot syndrome virus (WSSV) infection and stress tolerance (salinity stress), were not significantly different among treatments. Trial II was performed in juvenile shrimp (10 g average body weight) fed test diets containing 100 ppm astaxanthin (Lucanthin pink®), 125 mg/kg β-carotene (Lucarotin®), 250 mg/kg β-carotene (Lucarotin®), 250 mg/kg Betatene® and 3% dried Spirulina compared with those fed control diet without carotenoid. At the end of 6 weeks feeding period, shrimp fed control diet as well as astaxanthin and dried Spirulina supplemented diets had higher levels of total hemocyte counts than those of all β-carotene supplemented diets feeding group. However, phenoloxidase activity and clearance of pathogenic vibrio from the hemolymphwere not significantly different among the treatments (p>0.05). Astaxanthin levels were highest in the shrimp fed all carotenoid-supplemented diets. In conclusion, a natural carotenoid i.e. dried Spirulina and carotenoid extracted from Dunaliella which have a lower production cost than analytical carotenoid showed beneficial effects on shrimp feed supplement