| Summary: | 碩士 === 國立屏東科技大學 === 熱帶農業暨國際合作系 === 106 === The study investigates the oral administration of the hot water plant extract of Scutellaria radix mixed with diet to stimulate immunity and increase disease resistance in Macrobrachium rosenbergii. The herbal roots (S. radix) crude extract is rich in bioactive compounds, the aglycones (baicalein, wogonin and oroxylin A) and glycosides (baicalin, wogonoside and oroxyloside). The S. radix was ground into powder, autoclaved with 1000 mL of distilled water at 5 g, 10 g and 20 g per kilogram of feed to make 0.5%, 1% and 2% of the crude extract, respectively. A total of 800 mL of the crude extract mixed with the feed ingredients using a mixer machine; processed into a spaghetti form to make pellets and air dried at room temperature. Feed drying process included blowing feed under room temperature using an electric fan. Approximately 420 prawns, 30 prawns per 300 L tank acclimatized at 28 °C under water and circulation system. Feeding the self-formulated diet (control diet) lasted for a week and later fed the diet enriched with S. radix for 14 days. The effect of the herbal extract on immune response was analyzed at different time points (D0, D1, D2, D4, D7, and 14D, respectively). For the susceptibility test, five treatments of 30 prawns per
treatment kept in triplicates, 10 shrimps per 40 L of aerated water in 60 L rectangular tanks and continuously fed supplemented diet of the S. radix. The shrimps then challenged with Lactococcus garvieae on the day 24 of the feeding experiment. Furthermore, the shrimps continuously fed the treatment diet and observed for survival rate and data analysed for 6 h, 48 h, 72 h and 144 h of the experimental period. Observed immunity involved the cellular, enzyme, activities and expression of immune related genes. The study indicated the up and down regulation on the immune related genes. Also observed were the anti-pathogen properties of the S. radix. The data analysed by statistical package, Statistics Package for Social Science (SPSS), version 22 and presented as the mean ± SD, p < 0.05 and * p < 0.05, **p < 0.01, ***p< 0.001. Diet enriched with S. radix significantly improved immunity and decrease mortality rate against L. garvieae. Feeding the S. radix concentrated diet increased cellular activity at 0.5% and 2%. The diet concentration also increased the effects of reactive oxygen species activity at D2, D7, and D14, respectively. Likewise, the supplemented diet improved enzyme activities such as transglutaminase activity and was realized at 2% of feed concentration. Correspondingly, feed concentration of 0.5 % and 1% significantly increased the phenoloxidase activity. Moreover, feeding the herbal extract supplemented diet decreased mortality rate against L. garvieae. Finally, an up and down regulation of immune related genes was observed; 0.5% feed concentration up regulated significantly at D 1 and D 14. This study is important for the development and implementation of sustainable diseases management strategies using herbal extracts in aquaculture. In addition, the study is important of advancement of food and nutrition security, health using herbal medicine to control diseases.
Keywords: Lactococcus garvieae, Scutellaria radix, Macrobrachium rosenbergii, supplemented diet, immunity
|
|---|
