文献类型： 外文期刊

作者： Zhao, Fangyue ¹ ; Xu, Pao ¹ ; Xu, Gangchun ¹ ; Huang, Dongyu ¹ ; Zhang, Lu ³ ; Ren, Mingchun ¹ ; Liang, Hualiang ¹ ;

作者机构： 1.Nanjing Agr Univ, Wuxi Fisheries Coll, Wuxi 214081, Peoples R China

2.Chinese Acad Fishery Sci, Freshwater Fisheries Res Ctr, Key Lab Integrated Rice Fish Farming Ecol, Minist Agr & Rural Affairs, Wuxi 214081, Peoples R China

3.Tongwei Co Ltd, Hlth Aquaculture Key Lab Sichuan Prov, Chengdu 610093, Peoples R China

关键词： Largemouth bass ( Micropterus salmoides ); Valine; Growth performance; Intestinal health; Antioxidant

期刊名称：ANIMAL FEED SCIENCE AND TECHNOLOGY （ 影响因子：3.2； 五年影响因子：3.6 ）

ISSN： 0377-8401

年卷期： 2023 年 295 卷

页码：

收录情况： SCI

摘要： This study investigated the effect of dietary valine on growth, whole-body composition, plasma parameters, and intestinal genes expression related to TLR-MyD88-NF-xB signaling pathways of the largemouth bass. An 8-week feeding trial was designed to evaluate the effects of dietary valine levels on the growth performance, intestinal immunity, and antioxidant capacity of largemouth bass. Graded valine levels were used to produce six practical diets: 1.77% (control), 2.02%, 2.26%, 2.49%, 2.71%, and 2.94%. The findings demonstrated that, up to a dietary valine level of 2.26%, the weight gain rate, final body weight, condition factor, and specific growth rate all increased and thereafter declined (P < 0.05). The feed conversion ratio had the opposite trend but with no significant difference (P > 0.05). Dietary valine had no significant effects on HSI (hep-atosomatic index), VSI (visceral adipose index) or the whole-body composition of largemouth bass (P > 0.05). The 2.26% dietary valine level significantly increased intestinal antioxidant factor activity, including the activities of CAT (catalase) and SOD (superoxide dismutase) (P < 0.05). The fish fed 2.94% dietary valine had the highest level of GSH (glutathione) (P > 0.05) and the highest activity of GPx (glutathione peroxidase) (P < 0.05). The 2.71% dietary valine level significantly reduced the MDA (malondialdehyde) content compared with that of the control group (P < 0.05). The 2.26% dietary valine level dramatically reduced the mRNA levels of IL-8 (interleukin-8), TNF-alpha (tumor necrosis factor-alpha), IL-1 beta (interleukin 1 beta), NF-xB p65 (nuclear fac-tor kappa B p65), IL-10(interleukin 10), keap1 (kelch-like ECH-associated protein 1), C3 (caspase 3), MyD88 (myeloid differentiation factor 88), TLR2 (Toll-like receptor 2), CAT, and GPx and increased the mRNA level of SOD in the largemouth bass intestine when compared to levels in the control group (P < 0.05). The Nrf2 (nuclear factor 2-related factor) mRNA level was also increased but was not significantly different (P > 0.05). The mRNA levels of TGF-beta (transforming growth factor beta) did not change significantly (P > 0.05). In conclusion, according to the FCR (feed conversion ratio)-and SGR (specific growth rate)-based quadratic regression analyses, the op-timum requirements for valine are 2.43% (5.01% of dietary protein) and 2.37% (4.95% of dietary protein), and 2.26% dietary valine help to improve the immune and antioxidant capacity of the intestine in largemouth bass.