AUTHOR=Tang Hao , Luo Sheng , Chen Jifeng , Zhou Qianjin , Yang Guanjun , Lu Jianfei , Chen Jiong 

TITLE=Effects of dietary Silphium perfoliatum L. on the growth performance, immunity, intestinal health, and resistance against Nocardia seriolae of largemouth bass (Micropterus salmoides)

JOURNAL=Frontiers in Marine Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1432379

DOI=10.3389/fmars.2024.1432379

ISSN=2296-7745

ABSTRACT=<p>The present study was conducted to evaluate the effect of dietary <italic>Silphium perfoliatum</italic> L. on growth performance, immunity, intestinal health, and resistance against <italic>Nocardia seriolae</italic> of largemouth bass. Four dietary concentrations of <italic>S. perfoliatum</italic> L. were prepared: 0% (SPL0), 1% (SPL1), 2.5% (SPL2.5), and 5% (SPL5). After 60 d feeding, a challenge test was conducted by injecting <italic>N. seriolae</italic> intraperitoneally. The results showed that supplementing the diets with <italic>S. perfoliatum</italic> L. could promote the weight gain rate, specific growth rate, and feed intake. Meantime, <italic>S. perfoliatum</italic> L. could also enhance the activity of immune-related enzymes and improve the expression of immune-related genes in the liver. Compared to the control group, <italic>S. perfoliatum</italic> L. improved intestinal morphology and reduced the abundance of harmful bacteria in intestinal microbiota. Importantly, supplementing the diets with <italic>S. perfoliatum</italic> L. protected largemouth bass from <italic>N. seriolae</italic> infection, resulting in a relative percent survival (RPS) of 24% (SPL1), 31.99% (SPL2.5), and 43.99% (SPL5). In conclusion, the present study showed that <italic>S. perfoliatum</italic> L. could boost growth performance, enhance immunity, promote intestinal health, and improve the ability of largemouth bass against <italic>N. seriolae</italic> infection.</p>