| Deoxynivalenol(DON,vomitoxin)mainly produced by Fusarium graminearum,is a toxic fungal secondary metabolite that frequently contaminates grains such as wheat,corn and other crops with high detection rate often above standard.And DON is the main mycotoxin contaminant in livestock feed or feed raw materials.In recent years,a trend in aquatic feed production forms of cheaper plant protein sources replacing animal protein sources to reduce the production cost.So the mycotoxin pollution and its impact in aquatic feed seriously endanger animal health and public safety of human beings.Growth performance,the serum biochemical profiles,flow cytometry profiles,extensive non-targeted metabolomics of Oreochromis aureus were analyzed after fed with feeds containing DON(0,1,2,3 mg/kg)in a 8-week trial.Results showed that:1.growth performances and hematological parameters.The eco-physiological indexes and blood routine indexes of each group fish were tested.The results showed that fish groups fed with feeds containing DON(1-3 mg/kg)significantly reduced the weight gain rate,specific growth rate,thermal growth coefficient and feed efficiency(p<0.05),which group DON 3 mg/kg showed the most significant effect.Meanwhile leukocytes number significantly changed in fish groups fed with feeds containing DON(1-3 mg/kg)(p<0.05).But there were no significant changes of these groups in the indexes such as the hemoglobin concentration,red blood cell backlog,red blood cell volume,red blood cell hemoglobin content,red blood cell hemoglobin concentration,red blood cell distribution width variation coefficient,Platelet volume and platelet distribution width.2.Changes in immune functionFish immune function of all groups were examined through the serum biochemical analysis technology.Results showed that serum malondialdehyde(MDA)concentration,alanine aminotransferase(ALT),aspartate aminotransferase(AST)And alkaline phosphatase(ALP)activity increased significantly(p<0.05),superoxide dismutase(SOD)activities decreased significantly(p<0.05)in all groups fed with feed containing DON(1-3 mg/kg)while glutathione catalase activities did not change significantly.3.reactive oxygen,esterase and nitric oxide in tilapia blood cellsBased on flow cytometry analysis,tilapia blood cell reactive oxygen species(ROS)and nitric oxide(NO)of test groups significantly increased(p<0.05),and esterase activities were significantly decreased(p<0.05)in all test group fish.4.serum metabolomicsBased on a wide range of targeted metabolomics techniques,tilapia sera metabolomics were tested.A total of 27 differential metabolites were screened,of which 19 differential metabolites were significantly down-regulated and 8 differential metabolites were significantly up-regulated.There were 57 pathways involved in differential metabolites,of which 25 pathways were related to metabolism,14 pathways were related to biological systems,12 pathways were related to human diseases,4 pathways were related to environmental information processing,and 2pathways were related to genetic information processing.It could be concluded that DON in feed could reduce the growth performance of tilapia,causing oxidative stress in tilapia,destroying the body’s immune system,causing peroxidative stress on the body,thereby reducing the body’s immunity and may have certain damage effect.Secondly,DON in the feed had a certain toxic effect on tilapia blood cells,specifically changing the cell activity,triggering oxidative damage to the cells and reducing the body’s immunity.In addition,DON in the feed could also cause disturbance of tilapia energy metabolism,which disrupted the metabolism of ribonucleotides,amino acids and organic acids,lipid synthesis and metabolism,oxidized lipid metabolism,etc.Serum metabolism regulation,which in turn affected the growth and development of fish. |
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