饲料中过高或过低的脂肪水平对大口黑鲈生长性能和肠道健康的影响OA

This study aimed to investigate the effects of dietary excessively high or low fat levels on growth performance and intestinal health of largemouth bass(Micropterus salmoides).A total of 270 largemouth bass with an average initial body weight of(2.68±0.01)g were selected and randomly divided into 3 groups with 3 replicates per group and 30 fish per replicate.The dietary fat levels of the control group,low-fat group and high-fat group were 10%,4%and 18%,respectively.The experiment lasted for 8 weeks.The results showed that compared with the control group,dietary excessively high or low fat levels affected the growth perform-ance of largemouth bass,which showed the weight gain rate and specific growth rate were significantly de-creased(P＜0.05),and the feed conversion ratio was significantly increased(P＜0.05);weakened the intesti-nal antioxidant capacity,which showed the intestinal malondialdehyde content was significantly increased(P＜0.05),and the intestinal superoxide dismutase and catalase activities were significantly decreased(P＜0.05);induced the intestinal inflammation,which showed the gene relative expression levels of interleukin-1β(IL-1β),interleukin-8(IL-8)and transforming growth factor-β(TGF-β)in intestine were significantly up-regula-ted(P＜0.05);aggravated the intestinal apoptosis,which showed the gene relative expression levels of cystei-nyl aspartate proteinase 3(Caspase3)and cysteinyl aspartate proteinase 9(Caspase9)in intestine were signifi-cantly up-regulated(P＜0.05);reduced the intestinal microbiota α diversity and changed its composition,which showed the relative abundances of Firmicutes and Mycoplasma in intestine were significantly increased(P＜0.05),and the relative abundances of Cyanobacteria and Actinobacteriota in intestine were significantly decreased(P＜0.05).In conclusion,dietary excessively high or low fat levels have negative effects on the growth performance and intestinal health of largemouth bass.[Chinese Journal of Animal Nutrition,2026,38(3):2113-2127]