Heat-labile enterotoxin antibodies in calves.

The presence of antibodies to Escherichia coli heat-labile enterotoxin (LT) was measured in serum samples collected from 91 calves. Of these animals, 87 per cent had detectable levels of anti-LT in a seroneutralisation test performed in the Y1 adrenal cell time.     

Effects of High Environmental Temperature on Serum Oxidative Stress Factors and Jejunal Mucosal Mechanical Barrier Function in Tongcheng Pigs

The study was aimed to investigate the effects of high temperature on serum oxidative stress indexes and jejunal mucosal mechanical barrier function in Tongcheng pigs.Thirty 100-day-old female Tongcheng pigs with similar genetic backgrounds and average initial body weight of 45 kg±5 kg were randomly divided into six groups.All pigs were firstly raised under (28±1) ℃ with ad libitum feeding for 7 d.Then the control group was still raised under (28±1) ℃,the high temperature groups were treated with heat preservation lamps,and the temperature was rapidly raised to (38±1) ℃.Pigs were slaughtered and samples were collected at 2,4,6,8,and 10 days,respectively.Serum oxidative stress indexes and the expression levels of mechanical barrier and inflammatory factor-related mRNA in jejunum mucosa were detected.HE sections and immunohistochemical staining were performed on jejunum tissues.The results showed that ①Compared with the control group,the content of serum MDA and GSH-Px activity decreased significantly on the 2nd day of high temperature (P<0.05),and then stabilized.There was no significant change in serum SOD in high temperature groups (P>0.05).Serum T-AOC increased significantly on the 2nd and 8th day of heat treatment (P<0.05).②Compared with the control group,the expression of tight junction proteins ZO-1,OCLN,CLDN5 and CLDN7 mRNA decreased significantly (P<0.05),while the expression of cytoskeleton proteins IQGAP1,IQGAP2 and IQGAP3 mRNA decreased significantly (P<0.05),and the expression of Rac1 mRNA decreased significantly (P<0.05),the expression of Rac2 and Rac3 mRNA did not change significantly (P>0.05) in the heat stress group (2 days).Compared with the control group,the expression of HSP70 in jejunal mucosa increased,mucosal structure was damaged and inflammation occurred in heat stress group.In conclusion,Tongcheng pigs had good antioxidant stress regulation ability under high temperature environment,but high temperature would weaken jejunal barrier function.     

环境高温对通城猪血清氧化应激因子及空肠黏膜机械屏障功能的影响

试验旨在研究高温环境对通城猪血清氧化应激指标及空肠黏膜机械屏障功能的影响。选取遗传背景相似、100日龄、体重（45±5）kg的通城猪30头（母猪），随机分为6组，每组5头，分别为对照组和高温2、4、6、8、10 d处理组。试验猪自由采食、自由饮水，（28±1）℃下适应性饲养7 d。从第8天开始，对照组仍于（28±1）℃饲养，高温组猪舍悬挂保温灯，迅速升温至（38±1）℃，饲养至相应天数屠宰采集样品，测定血清氧化应激指标和空肠黏膜机械屏障和炎性因子相关mRNA表达水平，并对空肠组织进行HE切片和免疫组化染色观察。结果表明：①与对照组相比，在高温第2天，血清丙二醛（MDA）含量和谷胱甘肽过氧化物酶（GSH-Px）活性显著降低（P<0.05），随后趋于稳定；高温各组血清总超氧化物歧化酶（SOD）活性无显著变化（P>0.05）；血清T-AOC在高温第2、8天显著升高（P<0.05）；②与对照组相比，高温组（2 d）空肠紧密连接蛋白ZO-1、OCLN、CLDN5和CLDN7 mRNA表达量显著降低（P<0.05）；细胞骨架蛋白IQGAP1无显著变化（P>0.05）；IQGAP2和IQGAP3 mRNA表达量显著降低（P<0.05）；Rac1 mRNA表达量显著降低（P<0.05），Rac2和Rac3 mRNA表达量无显著变化（P>0.05）。与对照组相比，高温组（2 d）空肠黏膜HSP70表达量增高，黏膜结构破损并有炎症产生。综上，通城猪在高温环境下具有较好的抗氧化应激调节能力，但高温环境会使其空肠屏障功能减弱。     

早期断奶仔猪饲粮丙氨酰谷氨酰胺适宜添加量的研究

本文旨在研究丙氨酰谷氨酰胺(Ala-Gln)对早期断奶仔猪生长性能、血液生化指标和小肠黏膜酶活性的影响,探讨Ala-Gln在早期断奶仔猪饲粮中的适宜添加量.选用48头(公母各占1/2)纯种云南撒坝仔猪为试验对象,35日龄断奶,按单因素完全随机化设计分为4组,每组3个重复,每个重复4头猪.各组分别饲喂在基础饲粮上添加0(对照组)、0.15％、0.30％、0.45％ Ala-Gln的试验饲粮,试验期为35 ～ 60日龄.结果表明:1)0.30％组显著提高了全期仔猪平均日增重和平均日采食量(P＜0.05),随着Ala-Gln添加水平的提高,全期仔猪平均日增重和平均日采食量以二次曲线方式提高(P=0.004和P=0.006);2)0.30％组极显著提高了49日龄仔猪血清总蛋白、葡萄糖含量及谷丙转氨酶活性(P＜0.01),显著提高了血清碱性磷酸酶活性(P＜0.05),极显著降低了血清尿素氮含量(P＜0.01),显著降低了乳酸脱氢酶活性(P＜0.05).各组血清白蛋白、肌酐含量及肌酸激酶活性均差异不显著(P＞0.05).3)试验组仔猪空肠黏膜钠泵(Na+ -K+ -ATPase)和总二糖酶活性均显著或极显著高于对照组(P ＜0.05,P＜0.01).结果提示,添加适量的Ala-Gln对早期断奶仔猪具有一定的促生长效应,在本试验条件下,依据二次曲线拟合结果,推荐Ala-Gln适宜添加量为0.27％.     

马齿苋水提物对热应激小鼠空肠结构及吸收功能的影响

旨在探讨马齿苋水提物（aqueous extract of Portulaca oleracea L.）对热应激小鼠空肠结构及吸收功能的影响。将40只昆明种小鼠随机分为4组（n=10）：空白对照组（C）、热应激组（HS）、马齿苋水提物组（AEP）、维生素C组（Vc），HS、AEP和Vc组每天于（40±1）℃环境下处理0.5 h，连续热应激6 d后将小鼠转置于室温下给药治疗。给药7 d后眶窦采血，并采集小鼠空肠；测定小鼠血清中D-木糖、葡萄糖含量；HE染色观察空肠组织病理学变化；qRT-PCR法检测空肠黏膜ZO-1、SGLT1及GLUT2 mRNA的相对转录水平。结果显示，与C组比较，HS组小鼠空肠黏膜绒毛高度极显著降低（P<0.01）；血清中D-木糖的含量极显著降低（P<0.01）；空肠黏膜中ZO-1、SGLT1和GLUT2 mRNA的相对转录水平均极显著降低（P<0.01）；与HS组相比，AEP组小鼠空肠绒毛高度极显著提高（P<0.01）；血清中D-木糖及葡萄糖的含量均显著升高（P<0.01或P<0.05）；空肠黏膜中ZO-1、SGLT1和GLUT2 mRNA的相对转录水平均显著升高（P<0.05或P<0.01）。高温处理可导致小鼠空肠黏膜脱落及吸收功能下降，而在给予马齿苋水提物治疗后可通过提高空肠ZO-1 mRNA表达量修复空肠黏膜结构，通过促进空肠黏膜SGLT1和GLUT2 mRNA的转录量改善吸收功能。马齿苋水提物能在一定程度上修复热应激导致小鼠空肠黏膜结构损伤，改善热应激小鼠肠道的吸收能力。     

Oral administration recombinant porcine epidermal growth factor enhances the jejunal digestive enzyme genes expression and activity of early-weaned piglets

This study attempted to determine ingested porcine epidermal growth factor (pEGF) on the gastrointestinal tract development of early-weaned piglets. Thirty-two piglets (14-day weaned) were randomly allotted to supplemented with 0 (control), 0.5, 1.0, or 1.5 mg pEGF/kg diet. Each treatment consisted of four replicates with two pigs per pen for a 14 days experimental period. Piglets were sacrificed and gastrointestinal tract samples were collected to measure mucosa morphology, mRNA expression and activities of digestive enzymes in the gastrointestinal tract of piglets at the end of the experiment. Diets supplemented with pEGF failed to influence growth performance but tended to increase jejunal mucosa weight (p < 0.09) and protein content (p < 0.07). Piglets supplemental pEGF induced incrementally the gastric pepsin activity (p < 0.05) and stimulated jejunal alkaline phosphatase (ALP) and lactase activities accompanied with the increase of jejunal ALP and maltase mRNA expression. No effect of pEGF on the activities of all enzymes in ileum except the stimulation of ileal aminopeptide N mRNA expression. These results reveal that dietary pEGF supplementation might enhance gene expression and activities of digestive enzymes in the stomach and jejunum of piglets.     

Effects of beta-glucanase and xylanase supplementation on gastrointestinal digestive enzyme activities of weaned piglets fed a barley-based diet

The effects of supplementing a barley-based diet for weaned piglets withexogenous beta-glucanase and xylanase on gastrointestinal digestiveenzyme activities were investigated. Thirty-six cross-bred weaned pigletswere randomly assigned to two groups with three pens based on sexand mass. Each group was fed on the diet based on barley with or withoutadded beta-glucanase and xylanase (0.15%) for a 4-week period. Theresults showed that enzyme supplementation improved growth performanceof piglets significantly (p < 0.05), but had no effect (p = 0.091)on average daily feed intake. The results also showed that supplementationof beta-glucanase and xylanase had no effect on pepsin activity in gastriccontents but slightly decreased (p = 0.092) the pepsin activity ingastric mucosa. Meanwhile, no effect of enzyme supplementation ontrypsin activity in duodenal contents was observed. However, the activitiesof amylase and lipase in duodenal contents were significantly(p < 0.05) decreased, whereas the activities of maltase, sucrase andgamma-glutamyl transpeptidase (gamma-GT) in jejunal and ileal mucosa wereenhanced significantly (p < 0.05). The improvement of disaccharidaseand gamma-GT activity may be attributed to the positive impacts of exogenousenzymes on digestion and absorption of the nutrients. In conclusion,the current results indicated that supplementation with enzymes in barley-based diets could improve the growth performance of piglets,decrease the activities of amylase and lipase in duodenal contents andincrease the activities of disaccharidase and gamma-GT in jejunal and ilealmucosa.     

超早期断奶应激对仔猪消化酶活性的影响初报

试验选用两窝１４ 日龄杜×（ 大×长） 三元杂交商品猪,每窝１０ 头,每窝仔猪按体重平均分为断奶处理组和哺乳对照组,每组两个重复（ 栏） ,每栏５ 头猪。分别于断奶后第０（１４ 日龄） 、２ 、４ 、６ 、９ 天从每栏内随机抽取一头猪,屠宰后取胰腺和空肠内容物样品,测定胰蛋白酶、淀粉酶及脂肪酶活性。试验结果表明,断奶应激不同程度地降低了仔猪胰腺和空肠内容物中胰蛋白酶、淀粉酶和脂肪酶活性。随着断奶后时间的推移和采食量的增加,断奶仔猪空肠内容物中胰蛋白酶、脂肪酶以及胰腺中淀粉酶活性得以恢复并呈上升趋势。     

Effects of small intestinal ischemia and reperfusion on expression of tumor necrosis factor-alpha and interleukin-6 messenger RNAs in the jejunum, liver, and lungs of dogs

OBJECTIVE: To determine the effects of intestinal ischemia and reperfusion on the expression of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 mRNAs in the jejunum, liver, and lungs of dogs. ANIMALS: 8 healthy adult Beagles. PROCEDURES: In each dog, the cranial mesenteric artery was occluded for 0 (control group; n=4) or 60 (I-R group; 4) minutes, followed by reperfusion for 480 minutes; serum TNF-alpha and IL-6 activities and expression levels of TNF-alpha and IL-6 mRNAs in jejunal, hepatic, and lung tissues were measured before and at the end of the ischemic period and at intervals during reperfusion. For each variable, values were compared between the control and I-R groups at each time point. RESULTS: Compared with the control group, serum IL-6 activity increased significantly after 180 minutes of reperfusion in the I-R group; also, jejunal TNF-alpha mRNA expression increased significantly after 60 (peak) and 180 minutes of reperfusion. In the I-R group, expressions of IL-6 mRNA in the liver and TNF-alpha and IL-6 mRNAs in the lungs increased significantly at 480 minutes of reperfusion, compared with the control group. Serum TNF-alpha activity, expression of IL-6 mRNA in the jejunum, and expression of TNF-alpha mRNA in the liver in the control and I-R groups did not differ. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the liver, lungs, and jejunum contributed to the production of TNF-alpha and IL-6 after intestinal ischemia and reperfusion in dogs, suggesting that intestinal ischemia and reperfusion induce a systemic proinflammatory cytokine response in dogs.     

Effect of orally administered epidermal growth factor on the jejunal mucosa of weaned pigs

The effect of ingested epidermal growth factor (EGF) on the small intestinal mucosa of conventionally weaned pigs was determined. At 21 days of age, 39 pigs were randomly distributed into suckling and weaned treatment groups that were administered 124 micrograms of EGF, 372 micrograms of EGF, or the dosing compound daily. Fecal water content was determined daily. On postweaning days 0, 3, 6, and 9, representative pigs from each group were euthanatized, and jejunal mucosa samples were collected for determination of villus-to-crypt ratio, total protein content, disaccharidase activities, and microbiological populations. At postweaning day 3, the 372-micrograms dose of EGF significantly (P less than or equal to 0.05) increased jejunal lactase and sucrase activities in the weaned pigs. Increased lactase activity was not greater than that of the suckling pig controls, whereas sucrase activity was significantly (P less than or equal to 0.05) higher than that of the suckling pig controls. Significant changes were not observed in villus-to-crypt ratio, mucosal protein content, or disaccharidase activities on other collection days.     

Serum gamma-glutamyl transpeptidase activity in healthy cats and cats with induced hepatic disease

Activities of serum gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) were determined in healthy cats and in cats before and after treatment: common bile duct ligation, carbon tetrachloride administration, sham surgery, or anesthesia only. Significant (P less than 0.01) increases in serum GGT, ALP, and ALT occurred in cats with ligated bile ducts. Significant (P less than 0.01) increases in serum ALT occurred in carbon tetrachloride-treated cats. Increases of serum GGT, ALP, or ALT were not observed in cats subjected to sham surgery or anesthesia only compared with these cats' baseline values and values in healthy cats. Tissue GGT activity was measured in liver, renal cortex, jejunal mucosa, and bile ducts. There was a 1.5-fold increase in GGT activity in livers of cats with ligated bile ducts, compared with that in livers of healthy cats.     

空肠弯曲菌肠毒素间接ELISA检测法的建立

通过对ＣＥ３３种检测方法的比较研究,证实间接ＥＬＩＳＡ是检测ＣＥ最为敏感,简便,快速的方法,在２４ｈ内即可得到结果。ＣＨＯ法也较敏感,但要求较高。大鼠肠袢试验虽然操作繁杂,却是传统的肠毒素检测法,结果更具说服力。     

Use of chemical treatments to reduce antinutritional effects of tannins in salseed meal: Effect on performance and digestive enzymes of broilers

This study investigated the effects of chemical treatments of salseed (Shorea robusta) meal (SSM), on intake, growth performance, feed efficiency, and activities of digestive enzymes in broilers. Five experimental iso-nitrogenous and iso-caloric diets, one without SSM (control) and four SSM based, were formulated. The four SSM diets differed in the treatment given to the SSM. The USSM diet contained untreated SSM and the three other diets were contained SSM incubated with (820 ml/ kg of SSM DM) distilled water (pH 5.3), 0.67 M acetic acid (pH 2.4), or 0.67 M sodium hydrogen carbonate (pH 8.2) for 12 h at 37 °C. Inclusion of untreated SSM in the diets markedly depressed the feed intake, growth rate and, feed efficiency in broilers. Treatment of SSM with chemicals partly alleviated these negative effects on the performance of broilers. Growth rate of broilers was significantly higher on alkali and water treated SSM diets than on USSM diet. The broilers on alkali treated SSM diet consumed more feed than those on water or acid-treated SSM diets. Alkali and water treatments of SSM significantly improved the feed efficiency in broilers fed SSM diets however; the effect due to acid treatment was negligible. Inclusion of untreated SSM in diets caused the pancreatic hypertrophy and subsequent depression in the activity of chymotrypsin and α-amylase in pancreatic tissue. Treatment of SSM with alkali and water substantially increased the activity of chymotrypsin in the pancreas. The activities of trypsin, chymotrypsin and α-amylase in the jejunum were depressed with USSM diet. This depression in broilers was partly alleviated with alkali and water treatments to SSM. The activities of dipeptidase, sucrase, and maltase in the jejunal and duodenal mucosa were also depressed with USSM diet. Activity of dipeptidase in the duodenal and jejunal mucosa of the broilers fed treated SSM was improved with alkali treatment. It can be concluded that inclusion of SSM in the diets of broilers markedly depressed the activities of pancreatic and intestinal enzymes, feed consumption, and growth rate. Treatment of SSM with water or alkali improved the digestive enzymatic activity, intake, growth, and subsequently feed efficiency in broilers.     

小麦饲料中添加木聚糖酶对高原型藏羊胃肠道发育的影响

旨在分析小麦粉中添加木聚糖酶(xylanase, Xyl)对藏羊羔羊胃肠道发育的影响。选择同质性良好的2～3月龄高原型藏羊公羔60只,随机分为两组,每组30只,各组内设置5个重复。对照组(Control group)饲喂不含木聚糖酶的日粮,试验组(Test group)饲喂含0.2%木聚糖酶的日粮,试验分为预饲期10 d和正试期90 d。饲养试验结束时,两组各随机选取5只羔羊进行屠宰,采集消化道组织置于多聚甲醛固定,并收集血液、瘤胃和空肠内容物。结果显示：1)与对照组相比,试验组瘤胃的角质层厚度、颗粒层厚度,瓣胃的乳头长度、乳头宽度、角质层厚度、颗粒层厚度,皱胃的黏膜厚度以及十二指肠的肌层厚度,空肠的绒毛高度、黏膜厚度,回肠的肌层厚度显著提高(P<0.05);2)对照组瘤胃和血清的LPS含量显著高于试验组(P<0.05);3)相较于对照组,试验组瘤胃的糜蛋白酶、胰蛋白酶、脂肪酶活性以及空肠的糜蛋白酶、α-淀粉酶活性显著提高(P<0.05);4)试验组瘤胃的总抗氧化能力水平、谷胱甘肽过氧化物酶及过氧化氢酶活性以及空肠的总抗氧化能力水平、谷胱甘肽过氧化物酶、超氧化物歧化酶...     

运输应激对山羊血清和空肠中HSP27、HSP70和HSP90含量的影响

为探讨运输应激对山羊血清和空肠中HSP27、HSP70和HSP90 3种热休克蛋白含量的影响,试验选取12只赣西山羊,随机分为对照组、运输应激2 h组和运输应激6 h组,应用双抗体夹心ELISA法测定山羊血清和空肠中3种热休克蛋白浓度。结果表明:与对照组相比,运输2 h山羊血清中HSP70和HSP90极显著升高(P<0.01),空肠中HSP70和HSP90显著升高(P<0.05),血清和空肠中HSP27有升高趋势(P>0.05);与对照组相比,运输6 h后血清中HSP70和HSP90分别极显著和显著升高(P<0.05和P<0.01),血清中HSP27含量以及空肠中3种蛋白含量均无显著变化(P>0.05);与运输2 h相比,运输6 h后3种蛋白含量都极显著降低(P<0.01)。结果显示,山羊对运输应激在细胞水平的适应性调节与血清中HSP70和HSP90蛋白水平升高有密切联系,运输2 h山羊通过上调HSP70和HSP90对应激导致的空肠损伤发挥细胞保护作用。     

Change of Ferritin-binding Activity in the Serum of Foal after Birth

In mammal circulation, various ferritin-binding proteins (FBPs) are thought to be involved in the clearance of circulating ferritin after complex formation with it. However, horse FBPs are known to cause inhibitory effects on ferritin immunoassay due to the concealment of the ferritin molecule to anti-ferritin antibodies used in the ferritin immunoassay. These inhibitory effects are eliminated by heat treatment of horse serum at 75°C for 15 min. The inhibitory effects on ferritin immunoassay in the sera of ten foal sera (5 females and 5 males) from 1 to 18 months were detected during all periods, and ferritin concentrations of the foal sera increased 20–100% as compared with those of untreated sera by same heat treatment. Ferritin concentrations of heat-treated foal sera increased after birth, reaching to ferritin levels of adult horse at 9 months of age. Thereafter, although serum ferritin concentrations fell down at 12 months of age, these concentrations increased to adult levels at 15 months of age again. The ratio of ferritin concentration of heat-treated serum to that of the untreated serum was regarded as an apparent ferritin-binding activity. Ferritin-binding activities in the sera of foals showed peak at 2 and 4 months of age in females and males, respectively. These results suggested that horse FBPs were heat unstable, and FBPs may play an important role in iron metabolism at early developmental stage.     

丁酸梭菌和枯草芽孢杆菌对肉鹅生长性能、消化酶活性、抗氧化功能和肠道形态的影响

本试验旨在研究饲粮中添加丁酸梭菌和枯草芽孢杆菌对1~70日龄扬州鹅生长性能、消化酶活性、抗氧化功能和肠道形态的影响。选择1日龄健康、体重相近的扬州鹅公鹅288只,随机分为4组,每组6个重复,每个重复12只鹅。A组(对照组)饲喂基础饲粮,B组在基础饲粮中添加250 mg/kg丁酸梭菌(有效活菌数为3.0×10^6 CFU/g),C组在基础饲粮中添加250 mg/kg枯草芽孢杆菌(有效活菌数为2.0×10^7 CFU/g),D组在基础饲粮中添加250 mg/kg丁酸梭菌+250 mg/kg枯草芽孢杆菌。试验期10周。结果表明:1)B、C和D组总增重显著高于对照组(P<0.05),C、D组总采食量显著高于对照组(P<0.05)。2)B、C和D组空肠脂肪酶活性显著高于对照组(P<0.05)。3)C、D组血清和回肠总抗氧化能力显著高于对照组(P<0.05)。D组空肠谷胱甘肽含量显著高于对照组(P<0.05),C、D组空肠总超氧化物歧化酶活性显著高于对照组(P<0.05)。D组回肠谷胱甘肽过氧化物酶活性显著高于对照组(P<0.05)。4)C组空肠绒毛高度/隐窝深度(V/C)显著高于对照组(P<0.05)。B、C和D组回肠绒毛高度显著高于对照组(P<0.05),C、D组回肠V/C显著高于对照组(P<0.05)。由此可见,饲粮中添加丁酸梭菌和枯草芽孢杆菌及二者混合制剂可提高肉鹅总增重、空肠脂肪酶活性及抗氧化功能,添加枯草芽孢杆菌可更好地改善肠道形态。     

Enterotoxigenic Escherichia coli (ETEC) and Klebsiella pneumoniae isolated from dogs with diarrhoea

Faecal samples from 148 dogs with diarrhoea and from 15 healthy dogs were cultured for bacterial pathogens with enterotoxigenic properties. The aim of the study was to define the toxin profile (production of heat-labile [LT] and heat-stable [ST] toxins) and possible surface fimbrial antigens. Enterotoxigenic bacteria were isolated from 6 (4.1%) dogs with diarrhoea, four of these were Escherichia coli and two were Klebsiella pneumoniae. The E. coli strains and K. pneumoniae strains were producing both LT and ST toxins. The LT toxin from these strains was not neutralized by human anti-LT serum or anti-choleragen and did not cause coagglutination with Staphylococcus aureus coated with anti-human-LT. This suggests that the LT toxin produced by these canine isolates is non-identical to LT toxin from human strains.

Three of the ETEC strains were haemagglutinating and showed surface hydrophobic properties. Electron microscopy showed that canine ETEC isolates possessed fimbriae of two different types: thick (5–5.5 nm) and thin (2–3 nm).     

Local intestinal immune response to Escherichia Coli heat-labile (LT) enterotoxin: LT antitoxin levels in healthy, diseased and antigen-fed pigs

With purified LT toxin and IgA, specific anti-LT enterotoxin activity was demonstrated in small intestinal contents of 27 pigs. After 60 days of age, rise in intestinal LT antitoxin titer was observed. Feeding LT containing E. coli antigen increased LT antibody levels in the intestinal secretions, but decreased antibody titers in sera. In post-weaning E. coli diarrhea LT antibody levels in intestinal secretions and sera decreased significantly. This phenomenon can be related to the occurrence of the frequently observed post-weaning E. coli diarrhea.     

凝结芽孢杆菌BC-HYI改善脂多糖损伤蛋雏鸡肠道作用的研究

本试验旨在探究凝结芽孢杆菌BC-HYI调节脂多糖(LPS)损伤蛋雏鸡肠道作用。选取1日龄京红蛋雏鸡180只,随机分为5组,每组6个重复,每个重复6只,重复之间体重接近。空白对照组(CON组)和模型组(LPS组)饲喂基础饲粮,连续灌服生理盐水;3个益生菌组饲喂基础饲粮,同时分别连续灌服低、中、高剂量的凝结芽孢杆菌BC-HYI (浓度分别为106、107、108CFU/mL),连续灌服28 d,28 d后灌服LPS,灌服浓度为2 mg/kg,灌服剂量为200μL/只,试验周期为6 h,分别记为LOW+LPS、MID+LPS、HIGH+LPS组。6 h后采血,剖检、收集蛋雏鸡十二指肠、空肠、回肠肠道组织及空肠黏膜。结果表明：与空白对照组相比,LPS灌服后,蛋雏鸡十二指肠、空肠、回肠的绒隐比以及空肠黏膜黏液蛋白2(MUC2)、闭合蛋白(Occludin)和闭锁小带蛋白-1(ZO-1)mRNA相对表达量显著降低(P<0.05),血清二胺氧化酶(DAO)活性及D-乳酸(D-Lac)、肿瘤坏死因子-α(TNF-α)含量,空肠黏膜分泌型免疫球蛋白A(SIgA)和白细胞介素-10(IL-10)的含...