包膜丁酸钠对脂多糖刺激下断奶羔羊血清炎性细胞因子、肠道通透性及肠道组织形态的影响

本试验旨在研究包膜丁酸钠(CSB)对脂多糖(LPS)刺激下断奶羔羊血清炎性细胞因子、肠道通透性及肠道组织形态的影响。试验选取(42±1)日龄、平均体重为(11.79±0.54)kg的断奶羔羊24只,按体重相近原则随机分为4组:空白组(CON组)、LPS组、CSB2L组、CSB3L组,其中CON和LPS组饲喂基础饲粮,CSB2L和CSB3L组在基础饲粮中分别添加2和3 g/kg CSB,每组6个重复,每个重复1只羊。在试验第28天每组选取3只羔羊进行屠宰,LPS、CSB2L和CSB3L组在屠宰前3 h腹腔注射100μg/kg BW LPS,CON组腹腔注射等量无菌生理盐水。结果表明:1)与CON组相比,饲粮中添加CSB可显著提高断奶羔羊的平均日采食量(ADFI)(P<0.05),CSB3L组的平均日增重(ADG)显著高于CON和LPS组(P<0.05)。2)与CON组相比,LPS组断奶羔羊血清中肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-8(IL-8)含量显著升高(P<0.05)。CSB2L和CSB3L组血清TNF-α和IL-1β含量均低于LPS组(P<0.05),血清TNF-α含量显著高于CON组(P<0.05)。CSB3L组血清IL-8含量显著低于LPS组(P<0.05)。CSB2L和CSB3L组血清白细胞介素-10(IL-10)含量显著高于LPS组(P<0.05)。3)断奶羔羊血清中D-乳酸(DLA)含量和二胺氧化酶(DAO)活性在LPS刺激下显著升高(P<0.05)。CSB2L和CSB3L组可显著降低LPS注射后的血清DLA含量和DAO活性(P<0.05)。4)CON组肠黏膜形态结构完整且绒毛排列整齐。注射LPS后,空肠和回肠绒毛排列紊乱,高矮不一,绒毛肿胀脱落。CSB2L和CSB3L组空肠和回肠绒毛形态较完整且排列整齐,肿胀程度降低,上皮轻度脱落。LPS组盲肠部分肠绒毛上皮脱落,腺体排列紊乱,结肠绒毛略微脱落。CSB2L组盲肠和结肠有轻微水肿,CSB3L组盲肠和结肠绒毛上皮未见明显脱落和水肿。LPS刺激显著降低了空肠和回肠绒毛高度和绒毛高度/隐窝深度(P<0.05)。CSB2L和CSB3L组空肠和回肠绒毛高度降低和绒毛高度/隐窝深度降低均得到缓解。CSB2L和CSB3L组十二指肠绒毛高度显著高于CON和LPS组(P<0.05),CSB3L组回肠绒毛高度和绒毛高度/隐窝深度显著高于CON组(P<0.05)。由此可见,饲粮中添加CSB可以提高断奶羔羊的生长性能并能缓解LPS刺激引起的断奶羔羊应激,抑制血清促炎性细胞因子水平升高和肠道通透性增加,从而在一定程度上改善肠道组织形态,维护肠道健康。

Effects of Coated Sodium Butyrate on Serum Inflammatory Cytokines,Intestinal Permeability and Intestinal Morphology of Weaned Lambs Challenged with Lipopolysaccharide

This experiment was conducted to investigate the effects of coated sodium butyrate(CSB)on serum inflammatory cytokines,intestinal permeability and intestinal morphology in weaned lambs challenged with lipopolysaccharide(LPS).Twenty-four weaned lambs with an average body weight(11.79±0.54)kg were randomly allocated to 4 groups with 6 replicates per group and 1 lamb per replicate according to similar body weight:control group(CON),LPS group,CSB2L group and CSB3L group.CON and LPS groups were fed a basal diet,CSB2L and CSB3L groups were supplemented with 2 and 3 g/kg CSB,respectively.Three lambs in each group were slaughtered on the 28th day.LPS,CSB2L and CSB3L groups were intraperitoneally injected with 100μg/kg BW LPS,and CON group was intraperitoneally injected with the same amount of sterile normal saline 3 h before slaughter on the 28th day.The results showed as follows:1)the addition of CSB to the diet could significantly increase average daily feed intake(ADFI)of weaned lambs(P<0.05).The average daily gain(ADG)in CSB3L group was significantly higher than that in CON group or LPS group(P<0.05).2)Compared with CON group,the contents of tumor necrosis factor-α(TNF-α),interleukin(IL)-1βand IL-8 in serum of weaned lambs were significantly higher in LPS group(P<0.05).The contents of serum TNF-αand IL-1βin CSB2L and CSB3L groups were significantly lower than those in LPS group(P<0.05),and the content of serum TNF-αwas significantly higher than that in CON group(P<0.05).The content of serum IL-8 in CSB3L group was significantly lower than that in LPS group(P<0.05).The content of IL-10 in CSB2L and CSB3L groups was significantly higher than that in LPS group(P<0.05).3)LPS challenge significantly increased the D-lactate(DLA)content and diamine oxidase(DAO)activity in serum of weaned lambs(P<0.05).CSB2L and CSB3L groups can significantly decreased the DLA content and DAO activity after LPS challenge(P<0.05).4)The morphology and structure of intestinal mucosa were intact and the villi were arranged neatly in CON group.After challenge with LPS,the villi of jejunum and ileum were disorderly arranged,with different heights and swollen villi.In CSB2L and CSB3L groups,the villi of jejunum and ileum were relatively complete and neatly arranged,the degree of swelling decreased,and the epithelium was slightly exfoliated.In LPS group,villi epithelial cells were shed,glands were arranged disorderly and colonic villi fell were slightly shed.There was slight edema of cecum and colon in CSB2L group,and there was no obvious exfoliation and edema of cecal and colonic villous epithelium in CSB3L group.The villi height and villi height/crypt depth of the jejunum and ileum were significantly decreased(P<0.05).The decrease of villus height and villus height/crypt depth in jejunum and ileum were relieved in CSB2L and CSB3L groups(P<0.05).The villus height of duodenum in CSB2L and CSB3L groups was significantly higher than that in CON and LPS groups(P<0.05).Compared with CON group,ileum villi height and villi height/crypt depth were significantly increased in CSB3L group(P<0.05).It is concluded that dietary CSB can alleviate the stress of weaned lambs challenged with LPS,inhibit the increase of serum proinflammatory cytokines and intestinal permeability,then improve intestinal morphology and maintain intestinal health to a certain extent.