Supplementing Rotifers to Reduce Stress for White Shrimp

Supplementation of rotifers Ampithoe sp. in the diet helps to reduce stress for farmed\r\nshrimp.

The dense stocking density puts shrimp under serious\r\nenvironmental stress, increasing susceptibility to diseases, directly reducing\r\ncrop efficiency. Ammonia nitrogen (ammonia-N), a cause of stress in shrimp\r\nfarming, is mainly created by decomposing organic waste such as feed residues\r\nand shrimp feces in the water, too much ammonia-N content in the water. Accumulation\r\nin the organism affects growth, reduces survival and causes great economic\r\nlosses to the aquaculture industry. Effective methods to increase\r\nammonia-N tolerance of shrimp will have great implications for aquaculture.

To enhance the stress tolerance of aquatic animal farmers\r\ncan improve by increasing nutrition. Natural foods with high nutrient\r\ncontent and palatability have been used as nutritional supplements to enhance\r\nthe stress tolerance of shrimp.

Ampithoe sp. is\r\nrotifers rich in crude protein (51.2% dry weight), unsaturated fatty acids\r\n(41.9% of total fatty acids) and essential amino acids (22.2% of total amino\r\nacids). This is an excellent organism to reduce the accumulation of\r\nammonia-N and urea-N in the blood and enhance the ammonia-N tolerance of whiteleg\r\nshrimp (Shan et al., 2018). However, the supplement mechanism Ampithoe sp. Helping to\r\nimprove shrimp's stress tolerance is still unclear.

In the current study, the mechanism of increasing ammonia-N\r\ntolerance in vannamei was supplemented with Ampithoe sp. Freezing (FDPA) has been studied from the\r\nperspective of oxidative stress, metabolic network stress causing metabolic\r\ndisorders.

Research on\r\napplication of Ampithoe sp. to\r\nthe diet of white shrimp

In the current study, shrimp were divided into three groups\r\nand fed a supplemental diet containing 33% FDPA for 0 days (S0 group), 21 days\r\n(S21 group) or 42 days (S42 group). Subsequently, three groups of shrimp\r\nwere exposed to ammonia-N (1.61 mg / L) for 96 hours, and changes in oxidative\r\nstress, endothelial network stress (ER) and hepatic lipid metabolism. Pancreas\r\nhas been studied.

Result

After 21 days of exposure to ammonia, S0 group without FDPA\r\nsupplementation had the highest mortality rate of 46.7%, while the S21 group\r\nhad the lowest mortality rate of 30.0% and the feeding group had 42 days of\r\nmortality. 33.3%.

The activity levels of superoxide effutase (SOD) and\r\ncatalase (CAT) in the hepatopancreas of shrimp increased in the FDPA diet\r\ngroups compared to the S0 group. The level of malondialdehyd oxidation\r\n(MDA) and mRNA expression of the binding protein were significantly reduced in\r\nthe S21 and S42 groups compared to the S0 group.

Moreover, lipid synthesis (FAS), acetyl-CoA carboxylase\r\n(ACC) and malonyl-CoA (MCoA) were reduced; Carnitine palmitoyltransferase\r\n(CPT) activity has increased; and decreased free fatty acid (FFA) and triglyceride\r\n(TG) concentrations in the hepatopancreas of shrimp fed the FDPA diet compared\r\nto shrimp fed the control diet.

Ammonia-N stress causes oxidative stress in L. vannamei ,\r\nwhich causes endoplasmic reticulum stress in the hepatopancreas and leads to\r\nincreased lipid synthesis and reduced lipid breakdown. Results from the\r\nstudy indicated that adding 33% of FDPA to whiteleg shrimp feed within 21 days\r\ncould enhance antioxidant capacity and reduce ER stress due to ammonia-N\r\nexposure, thus ensuring metabolism, provide normal energy for the body and\r\nenhance the ammonia-N tolerance of whiteleg shrimp.

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This study provides useful information to enhance the\r\naquatic tolerance of aquatic animals by supplementing nutrition.

Source : tepbac