饲料中添加氯化胆碱对高脂胁迫细鳞鲑生长性能、肝脏抗氧化指标和脂代谢相关基因表达的影响OA

This experiment was conducted to investigate the effects of dietary choline chloride supplementation on the growth performance,hepatic antioxidant indices and expression of lipid metabolism-related genes of lenok(Brachymystax lenok)under high-fat stress.A total of 540 juvenile lenok with an initial body weight of(8.63±0.10)g were randomly divided into 6 groups with 3 replicates per group and 30 fish per replicate.A 2×3 two-factor design was employed,consisting of two dietary lipid levels[200(designated as C)and 230 g/kg(designated as H)]and three choline chloride supplemental levels(0,1 500 and 2 500 mg/kg).A total of six experimental diets were formulated(C-0,C-1500,C-2500,H-0,H-1500 and H-2500)and fed to the six groups of fish,respectively.The feeding trial lasted for 70 days.The results showed that:1)there were significant interactions between dietary lipid level and choline chloride supplemental level on final body weight(FBW),weight gain rate(WGR)and specific growth rate(SGR)of lenok(P＜0.05).All three indices reached their maximum values in the H-2500 group,at 22.90 g,166.76%and 1.39%/d,respectively.2)Sig-nificant interactions were also observed between lipid level and choline chloride supplemental level on hepatic superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)activities,as well as malondialdehyde(MDA)content(P＜0.05).Within both the C and H groups,hepatic SOD,CAT and GSH-Px activities increased with increasing dietary choline chloride supplemental level.In contrast,hepatic MDA content showed different trends,within the H group,it was significantly higher in the H-0 group than in the H-2500 group(P＜0.05).At the same choline chloride supplemental level,hepatic SOD,CAT and GSH-Px ac-tivities in the C group were higher to varying degrees than those in the H group,while hepatic MDA content was lower to varying degrees than that in the H group.3)Liver transcriptome sequencing was performed on the C-2500 and H-2500 groups,yielding 4 578 differentially expressed genes(2 380 up-regulated and 2 198 down-regulated).These genes were mainly enriched in pathways such as cholesterol metabolism,retinol me-tabolism,and oxidative phosphorylation.Compared with the C-2500 group,the expression of carnitine palmi-toyltransferase 1A(CPT1A),lipoprotein lipase(LPL),fatty acid desaturase 2(FADS2),solute carrier fami-ly 27 member 2(SLC27A2)and peroxisome proliferator-activated receptor alpha(PPARα)in the liver of the H-2500 group was significantly up-regulated(P＜0.05),while the expression of long-chain acyl-CoA syn-thetase(ACSL)was significantly down-regulated(P＜0.05).In conclusion,dietary supplementation with an appropriate level of choline chloride in a high-fat diet can improve the growth performance of lenok under high-fat stress,enhance hepatic antioxidant enzyme activities,and regulate the expression of key genes involved in lipid metabolism,thereby reducing hepatic lipid accumulation.Under the conditions of this experiment,the op-timal effect is achieved with the supplementation of 2 500 mg/kg choline chloride to a diet containing 230 g/kg lipid.[Chinese Journal of Animal Nutrition,2026,38(4):2917-2930]