This research investigated effects of dietary β-sitosterol addition at different levels on serum lipid levels, immune function, oxidative status, and intestinal morphology in broilers. One-day-old broiler chicks were allocated to 5 groups of 6 replicates. Chickens in the 5 groups were fed a basal diet supplemented with 0 (control group), 40, 60, 80, and 100 mg/kg of β-sitosterol for 42 D, respectively. β-Sitosterol linearly decreased (P < 0.05) concentrations of serum total cholesterol, jejunal tumor necrosis factor α (TNF-α), and ileal interleukin 1β (IL-1β) and mRNA relative expressions levels of jejunal TLR4 and ileal MyD88, whereas it linearly increased (P < 0.05) contents of jejunal immunoglobulin G (IgG), ileal secreted IgA and glutathione, jejunal catalase activity and Nrf2 mRNA relative expression level, villus height (VH), and VH-to-crypt depth (CD) ratio (VH:CD) in the jejunum and ileum. Linear and quadratic increases (P < 0.05) in absolute and relative spleen weight were observed by dietary β-sitosterol, whereas malondialdehyde (MDA) concentration in the jejunum and ileum followed the opposite trend (P < 0.05). Compared with the control group, dietary β-sitosterol at higher than or equal to 60 mg/kg level decreased (P < 0.05) contents of serum total cholesterol, ileal MDA, and jejunal TLR4 mRNA relative expression level, whereas it increased (P < 0.05) absolute spleen weight and ileal glutathione content. Higher than or equal to 80 mg/kg level of β-sitosterol enhanced (P < 0.05) jejunal IgG concentration, VH, catalase activity, and Nrf2 relative expression level and ileal secreted IgA content, but reduced (P < 0.05) ileal IL-1β content and MyD88 mRNA relative expression level. β-Sitosterol addition at 60 and 80 mg/kg levels increased (P < 0.05) relative spleen weight, whereas it decreased (P < 0.05) jejunal MDA accumulation. Moreover, 100 mg/kg level of β-sitosterol reduced (P < 0.05) jejunal TNF-α level, but it increased (P < 0.05) VH in the jejunum and VH:CD in the jejunum and ileum. Accordingly, dietary β-sitosterol supplementation could regulate serum cholesterol level, promote immune function, and improve intestinal oxidative status and morphology in broilers.

中文翻译：

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日粮β-谷甾醇调节肉鸡的血脂水平，改善其免疫功能，抗氧化状态和肠道形态。

这项研究调查了饮食中添加不同水平的β-谷甾醇对肉鸡血清脂质水平，免疫功能，氧化状态和肠道形态的影响。将一天大的肉鸡小鸡分为5组，每组6个重复。5组鸡分别饲喂基础饮食，其中补充0（对照组），40、60、80和100 mg / kg的β-谷甾醇，持续42D。β-谷固醇线性降低（P <0.05）血清总胆固醇，空肠肿瘤坏死因子α（TNF-α）和回肠白细胞介素1β（IL-1β）的浓度以及空肠TLR4和回肠MyD88的mRNA相对表达水平，而空肠免疫球蛋白G（IgG），回肠分泌的IgA和谷胱甘肽，空肠过氧化氢酶活性和Nrf2 mRNA相对表达水平，绒毛高度（VH），空肠和回肠的VH与隐窝深度（CD）之比（VH：CD）。饮食中的β-谷甾醇可观察到绝对和相对脾脏重量的线性和二次增加（P <0.05），而空肠和回肠中丙二醛（MDA）的浓度呈相反趋势（P <0.05）。与对照组相比，饮食中高于或等于60 mg / kg的β-谷甾醇降低了血清总胆固醇，回肠MDA和空肠TLR4 mRNA相对表达水平的含量（P <0.05），而升高了（P <0.05）。 0.05）绝对脾脏重量和回肠谷胱甘肽含量。高于或等于80 mg / kg的β-谷固醇水平可提高（P <0.05）空肠IgG浓度，VH，过氧化氢酶活性以及Nrf2相对表达水平和回肠分泌的IgA含量，但会降低（P <0。05）回肠IL-1β含量和MyD88 mRNA相对表达水平。以60和80 mg / kg的水平添加β-谷固醇相对脾脏重量增加（P <0.05），而空肠MDA积累减少（P <0.05）。此外，β-谷甾醇水平100 mg / kg降低了空肠TNF-α水平（P <0.05），但空肠VH和空肠和回肠VH：CD升高（P <0.05）。因此，饮食中添加β-谷甾醇可以调节肉鸡的血清胆固醇水平，促进其免疫功能，并改善肠道的氧化状态和形态。但它增加了（P <0.05）空肠中的VH和空肠和回肠中的VH：CD。因此，饮食中添加β-谷甾醇可以调节肉鸡的血清胆固醇水平，促进其免疫功能，并改善肠道的氧化状态和形态。但它增加了（P <0.05）空肠中的VH和空肠和回肠中的VH：CD。因此，饮食中添加β-谷甾醇可以调节肉鸡的血清胆固醇水平，促进其免疫功能，并改善肠道的氧化状态和形态。