| The laying hens are highly susceptible to fatty liver hemorrhage syndrome(FLHS)under the current intensive cage breeding mode in late laying period.The affected hens will suffer from lipid metabolism disorders,leading to the accumulation of lipids in the liver and increasing the metabolic burden on the liver,which will seriously affect the production performance of laying hens.The purpose of this experiment was to investigate the effect of garcinol on FLHS in late laying hens.A total of 180 57-week-old Jingfen No.6 laying hens were randomly selected and divided into 5 groups,including control group(Con),model group(Mod)and garcinol-treated groups.Garcinol-treated groups were supplemented with100mg/kg(T1),300 mg/kg(T2)and 500 mg/kg(T3)garcinol.Each group had 6 replicates and each replicate had 6 hens.The control group was fed the basal diet(metabolizable energy: 11.13 MJ/kg,crude protein: 15.59%)for normal hens,and the treatment group was fed the high energy low protein diet(metabolizable energy: 12.55 MJ/kg,crude protein:13.00%)for hens with fatty liver hemorrhagic syndrome.After 4 weeks of pretesting,the formal trial was started and the trial period was 11 weeks.At the end of the trial,serum and liver of laying hens were collected to determine liver function indexes,antioxidant indexes,lipid metabolism indexes and expression levels of genes related to lipid synthesis.The main findings of the study were as follows:1.Performance indicators showed that the egg production rate and feed intake of the model group decreased significantly and the feed-to-egg ratio increased significantly compared with the control group(P<0.05);the addition of 300 mg/kg and 500 mg/kg of garcinol to the diet significantly increased the egg production rate and decreased the feedto-egg ratio compared with the model group(P<0.05).2.Egg quality indexes showed that compared with the control group,the Haugh unit in the model group was significantly decreased on day 54 and day 81,and the protein height was significantly decreased on day 81(P < 0.05).Compared with model group,300 mg/kg and 500 mg/kg garcinol groups significantly increased the Haugh unit and protein height(P < 0.05).3.Liver histology and liver lipid deposition indexes showed that model group had severe liver damage.There were a large number of hemorrhagic spots and blood spots in the liver of the model group,a large number of fat vacuoles could be seen by HE staining,and a large number of red lipid droplets could be seen by oil red O staining.300 mg/kg and500 mg/kg garcinol groups significantly improved liver tissue damage.Compared with the control group,the liver index,abdominal fat percentage and liver fat percentage in the model group were significantly increased(P < 0.05),and the liver index,abdominal fat percentage and liver fat percentage in 300 mg/kg and 500 mg/kg garcinol groups were significantly decreased compared with the model group(P < 0.05).4.Liver function indexes showed that compared with the control group,the activities of ALT and AST in the model group were significantly increased(P < 0.01);Compared with model group,the activities of two enzymes in 300 mg/kg and 500 mg/kg garcinol groups were significantly decreased(P < 0.01).5.Serum and liver antioxidant indexes showed as follows: compared with the control group,the activities of serum and liver antioxidant enzymes T-SOD,GSH-Px and CAT in model group were extremely significantly decreased and MDA level was extremely significantly increased(P < 0.01);Compared with model group,500 mg/kg garcinol groups could significantly improve the activity of antioxidant enzymes and reduce the level of MDA(P < 0.01).6.Serum and liver lipid metabolism indexes showed that compared with the control group,the contents of TC,TG and L-DLC in serum and liver of model group were extremely significantly increased,while the contents of H-DLC were extremely significantly decreased(P < 0.01).Compared with model group,300 mg/kg and 500 mg/kg garcinol groups could reduce lipid deposition,significantly reduce the contents of TC,TG and L-DLC,and increase the content of H-DLC(P < 0.01).7.The expression results of liver fat synthesis-related genes showed that compared with the control group,m RNA expressions of FAS,ACC,SCD1 and SREBP-1c in liver tissues of model group were significantly increased(P < 0.05).Compared with model group,300 mg/kg and 500 mg/kg garcinol groups could significantly reduce the expression levels of the above genes(P < 0.05),and inhibit liver fat synthesis.In conclusion,the addition of garcinol to the diet had a dose-dependent effect on the production performance,egg quality and antioxidant capacity of FLHS hens;at the same time,the dietary supplementation of garcinol can alleviate the lipid metabolism level of the body and protect the structural and functional integrity of the liver by inhibiting the expression of genes related to liver lipid synthesis. |
PDF Full Text Request