Indian ginseng, alias ashwagandha, English name with the English name of witharia somnifera (WS), has a unique chemical composition and some functions that are beneficial to human health. In addition, WS is not only used in humans, but also has a significant impact on the growth and health of certain aquatic animals.
A latest study
Recently, a study on the nutritional value of WS on fisheries was published in the Journal of Fish and Shellfish Immunology (Volume 128, September 2022). A team of Mohsen Abdul-Tawab and his colleagues (Egypt) added Indian ginseng leaves to the feed to study the growth performance, digestive enzyme activity, intestinal tissue morphology, antioxidant-related genes of Penaeus vannamei, and the immune response and resistance of Harvey bacteria were studied for The American white shrimp that ate Indian ginseng.
Indian ginseng (witharia somnifera).
Preparation Method: The leaves of Indian ginseng (WSAE) are picked from the Matruh region of Egypt, rinsed 2 times with water, dried in the shade of a tree, and then ground with a machine until a uniform rough texture is reached. Next, soak 250 g of WS leaf powder for 24 hours and then cook in 1000 ml of hot water for 10 minutes. Then get an extract of Indian ginseng leaf.
Study feed: The control feed used in the study (40% crude protein) was added with Indian ginseng leaf extract (WSAE) 0, and the other three groups added 0.5, 1 and 2 g of Indian ginseng leaf extract to the 1 kg control feed, respectively.
How to add: WSAE mix with 100 ml of water and add to 1 kg of feed, after fine grinding, mix with a mixer for 30 min to homogenize and form granules (about 2 mm in diameter). These tablets are dried at < 10% humidity and refrigerated at 4 ° C until used to shrimp. Analysis results of chemical composition of feed: protein 41.5%; 3.3% crude fiber; 12.7% ash; Capacity 16.44KJ/kg feed.
Test method: The average initial weight of Penaeus vannamei is 0.34±0.04 g, taken from a shrimp fry production site of the Galión Project in Egypt. Before the start of the experiment, adapt to the salinity of 23 ‰ for 14 days. During this period, shrimp are fed a control feed (40% CP).
The shrimp were then randomly distributed to 15 plastic tanks (volume 1 m3/tank) with a density of 300 tails per tank, of which 3 tanks per study group. Shrimp are fed at 8:00, 12:30, 16:00 and 20:00 according to experimental feed within 56 days; Every two days, sewage discharge; Water quality is monitored daily by measuring the following parameters: pH (7.8-8.2), salinity (22-23‰), water temperature (28-31°C), total ammonia nitrogen (0.06-0.08 mg/L) and DO (6.5-6.8 mg/L).
The evaluation indicators of shrimp in this study include: growth efficiency; Activity of digestive enzymes; Morphology of intestinal tissue; Genes associated with antioxidants; Immune response and resistance to Harvey bacteria.
2. Results
1. The results show that after 56 days of testing, the growth parameters of the WSAE shrimp fed were higher than those in the control group, and the best results were observed in the 2 g WSAE/kg feed group test. In the WSAE-fed shrimp feed, the intake of shrimp was much higher in the control group, but there was no difference in the FCR (in the range of 1.66-1.68). There was no meaningful difference in the survival rate of shrimp in the experimental group from 95.6% to 96.7%. Compared to the control group, Penaeus vannamei was fed a feed containing WSAE, with excellent intestinal fuzz length, plush width and absorption area, especially in the 2 g/kg feed test (Figure 1). In addition, Penaeus vannamei fed with WSAE consumed more feed and exhibited higher total protein, lipase and a-amylase activity than the control group.
Figure 1: Changes in the length/width (mm) and absorption area (m㎡) of plush in the intestine after 56 days of feeding Indian ginseng (WSWE) extract.
2. Compared with the control batch, when the WSAE level in the feed rises to 2 g/kg of feed (Table 1), the above enzyme activity of eating WSAE shrimp gradually increases. In addition, the mRNA expression levels of cMn-SOD, CAT and GPx in the pancreatic liver tissue of Penaeus vannamei of Penaeus vannamei increased linearly after feeding with WSAE feed, and their maximum expression levels were observed in 2 g WSAE/kg feed.
Table 1: Changes in digestive enzymes (Unit/mg protein) in the intestinal tissues of Penaeus vannamei of Penaeus vannamei after feeding different proportions of Ginseng extract (WSAE) for 56 days.
3. The study also found that after infection with Vibrio Harvey, the survival rate of shrimp individuals fed 0.5 g WSAE/kg feed was significantly increased compared with the shrimp in the control group. The survival rates of Penaeus vannamei significantly improved in the feed WSAE, particularly in the 1 and 2 g/kg groups (61.3% and 66.7%, respectively).
Figure 2: Microscopic sections of intestinal tissue of Penaeus vannamei supplemented with Indian ginseng (WSAE), Penaeus vannamei in the feed. A: 0.5 g/kg feed; B plate: 1 g/kg feed; C: 2 g/kg feed; D: Control feed.
4. The results of this study show that the addition of WSAE to shrimp feed significantly improves growth indicators and feed intake, especially in 2 g WSAE/kg feed. Studies have also shown that significant increases in SOD, CAT and GPx activity, as well as GSH and TAC levels, are associated with a significant decrease in MDA levels in WSAE (2 g/kg feed). In addition, WSAE greatly adjusted mRNA expression of cMN-SOD, CAT, and GPx genes in the feed. These results show that the addition of WSAE to the feed increases the antioxidant capacity of the shrimp and protects the Penaeus vannamei from oxidative stress. Finally, studies have also demonstrated that P. vannamei can effectively control Vibrio harvey infection by eating WSAE-rich feed, which is the result of enhanced interactions between innate immune protection mechanisms.
3. Conclusions of the study
>> add 2 grams of WSAE to 1 kg of feed as a natural antioxidant that can enhance shrimp growth, digestive enzymes, intestinal health, antioxidant capacity and immunity.