健康奶牛子宫颈乳酸菌筛选方法的建立及其抑菌活性分析

为筛选用于防制奶牛子宫炎的乳酸菌菌株,本试验选取产后30~50 d的健康奶牛,采集子宫颈口处分泌物,利用MRS选择性培养基进行乳酸菌初步筛选。纯化后的菌株进行革兰氏染色镜检,将具有乳酸球菌或乳酸杆菌典型形态的疑似菌株进行针对性生化鉴定。提取分离菌株的基因组DNA,扩增其16S rDNA全序列并测序,将所得序列与NCBI数据库中的相应序列进行同源性比对分析。采用琼脂扩散法检测分离菌株对致病性金黄色葡萄球菌和大肠杆菌的抑菌活性,并检测分离菌株对山羊上皮细胞的黏附活性。结果显示,经染色镜检、生化鉴定和16S rDNA测序分析,得到13株乳酸菌,其中5株具有较强抑菌活性,6株具有较强黏附上皮细胞的能力,7、12和23号3株兼有良好的抑菌活性和黏附上皮细胞能力。综上,本试验建立了健康奶牛子宫颈中乳酸菌的筛选方法,得到3株具有良好益生特性的乳酸菌,为制备微生态制剂提供了基础材料,对防制奶牛子宫炎具有重要意义。     

复合微生态制剂对肉仔鸡生长性能、肠道菌群和免疫功能的影响

为研究探讨肉仔鸡日粮中添加不同剂量的复合微生态制剂对肉仔鸡生长性能、肠道菌群和免疫功能的影响,以期为复合微生态制剂的临床应用提供参考依据,将150只AA白羽肉仔鸡随机分成5个处理组(对照组、抗生素组、复合微生态制剂Ⅰ组、复合微生态制剂Ⅱ组、复合微生态制剂Ⅲ组),对照组饲喂基础日粮,抗生素组在基础日粮中添加0.05%的肉鸡饲用金霉素,复合微生态制剂Ⅰ、Ⅱ和Ⅲ组分别在基础日粮中添加0.05%、0.1%、0.2%的复合微生态制剂,测定平均日增重、平均日采食量、料重比、大肠杆菌数、沙门氏菌数、双歧杆菌数、乳酸杆菌数、胸腺指数、法氏囊指数、IgG含量、IgA含量、IgM含量等指标。结果显示,与对照组相比,复合微生态制剂Ⅱ组、Ⅲ组可显著增加平均日采食量、平均日增重、乳酸杆菌数、双歧杆菌数、胸腺指数、脾脏指数、法氏囊指数、IgA含量和IgG含量(P<0.05),显著降低料重比、大肠杆菌和沙门菌数(P<0.05)。与抗生素组相比,复合微生态制剂Ⅱ组、Ⅲ组可显著增加乳酸杆菌数、双歧杆菌数、胸腺指数、脾脏指数、法氏囊指数、IgA含量和IgG含量(P<0.05),显著降低料重比、大肠杆菌和沙门菌数(P<0.05)。表明肉仔鸡饲料中添加0.1%、0.2%的复合微生态制剂可显著改善提高肉仔鸡的生长性能、肠道菌群和免疫功能,其在改善肠道菌群和免疫功能方面的作用效果显著优于抗生素。     

添加酸马奶源乳酸杆菌对犊牛肠道菌群和短链脂肪酸含量的影响

选取刚出生的健康荷斯坦犊牛20头,随机分为酸马奶组、正常组、腹泻组和抗生素组,每组5头。除正常组外,其他3组在相同哺乳的基础上均口服100 mL致病性E.coli O1菌悬液(2.5×10¹¹ CFU/mL)建立腹泻模型,抗生素组添加环丙沙星0.5 mg/kg,试验期15 d。结果表明：酸马奶组犊牛肠道微生物丰富度与多样性显著高于其他3组(P<0.05)。酸马奶源乳酸杆菌干预后显著提高了肠道内厚壁菌门、普雷沃氏菌科、毛螺菌科未确定菌属和拟普雷沃菌属的相对丰度,降低了拟杆菌门、变形菌门、梭杆菌门、放线菌门的相对丰度;酸马奶组犊牛粪便中乙酸、丙酸和丁酸含量显著高于其他3组(P<0.05)。由此可见,犊牛日粮中添加酸马奶源乳酸杆菌可显著提高肠道微生物多样性,增加肠道中有益菌的丰度,降低有害菌的丰度,并显著提高其粪便中乙酸、丙酸和丁酸的含量。     

饲料乳酸菌类益生素的作用机制和应用

乳酸菌是一类近几年来研究较多的益生素。大量试验结果表明 ,乳酸菌中的一部分菌种对人和动物的保健和疾病治疗有效果。本文主要介绍了乳酸菌类益生素的作用机理 :提供部分必需氨基酸和维生素 ,产生酸和酶类 ,帮助宿主消化 ;调整消化道微生态平衡 ,通过颉颃作用抑制和排斥有害菌 ,以粘附抗性和竞争排斥限制有害菌体内定植 ,清除肠胃内有害物质 ;调节免疫系统功能     

乳酸菌益生功能及作用机制研究进

综述了近几年公开发表的一些研究结果,就乳酸菌对促进营养物质的吸收、预防和治疗疾病以及增强机体免疫力等益生功能的研究现状作了介绍,探讨了乳酸菌益生功能的作用机制,并对今后研究的发展方向作了简单分析。     

益生素和低聚木糖对断奶仔猪生产性能、消化酶活性、血液指标和肠道微生物的影响

选用(21±2)日龄体质量为(6.83±0.9)kg的PIC断奶仔猪240头,随机分为4个处理,正对照组(positive diet,PD)含有较多的鱼粉和乳清粉;负对照纽(negative diet,ND)舍有较少的鱼粉和乳清粉,较多的豆粕;负对照+0.035%益生素(negative diet+probiotics,ND+P);负对照+0.002%低聚木糖(negative diet+xylo-oligosaccharide,ND+X).饲喂至65日龄屠宰.结果显示,在断奶仔猪日粮中乳清粉和鱼粉从5.50%降低到2.50%,豆粕从22.50%增加到26.50%可导致仔猪消化道酶活性、血糖和血清总蛋白水平、盲肠乳酸杆菌数量降低(P<0.05),血清尿素氮、盲肠大肠杆菌数量、仔猪腹泻指数扣料重比增加(P<0.05).添加益生素和低聚木糖可以提高仔猪消化道蛋白质、脂肪和淀粉消化酶活性(P<0.05),降低料重比(P<0.05);提高血糖,降低血清尿素氮水平(P<0.05),改善蛋白质平衡和能量代谢;提高盲肠乳酸杆菌数量,减少大肠杆菌数量(P<0.05),降低仔猪的腹泻指数(P<0.05).添加益生素和低聚木糖与否,均不影响日增重和采食量(P>0.05).益生素和低聚木糖可以改善断奶仔猪的消化功能、后消化道有益菌群、饲料转化效率,防治仔猪腹泻.     

低聚木糖、益生菌及抗生素对肉鸡肠道菌群和生产性能的影响

选用1日龄健康AA肉雏鸡1200羽,随机分成6个处理,每个处理8个重复,分别饲喂添加抗生素(杆菌肽锌16.7mg·kg-1和硫酸粘杆菌3.3mg·kg-1,对照组)、低聚木糖(0.02%)、合生素(0.005%益生菌+0.005%及0.01%低聚木糖)、抗生素与低聚木糖(对照组抗生素+0.005%及0.01%低聚木糖)6种不同日粮,研究不同处理对肉鸡肠道微生物菌群和生产性能的影响。结果表明:与对照组相比,各试验组肉鸡空肠的乳酸菌数分别提高了19.89%(P<0.05)、9.17%、20.21%(P<0.05)、13.98%(P<0.05)和16.75%(P<0.05),除0.005%低聚木糖+抗生素组,其它各组大肠杆菌数量均较高。各试验组前期(0～21日)、后期(22～42日)和全期(0～42日)的肉鸡体增重分别提高了0.8%～15.1%、2.9%～29.0%和2.2%～24.0%,后期和全期饲料转化率分别改善了2.5%、4.3%、10.4%、16.9%、12.5%和1.0%、3.3%、6.2%、7.1%、6.2%,以添加0.005%低聚木糖+抗生素组的肉鸡增重、饲料转化率与成活率为最佳。     

复合益生菌对生猪健康状况影响的研究进展

益生菌作为一种新型抗生素替代品被广泛应用于畜牧业中。文章从乳酸菌、枯草芽孢杆菌和酵母菌复合益生菌能够促进生猪对营养物质的消化吸收和肠道发育,维持肠道菌群平衡,进而改善生猪肠道健康等方面进行阐述,为其在生猪上的应用提供参考。     

Effect of a potential probiotics Lactococcus garvieae B301 on the growth performance,immune parameters and caecum microflora of broiler chickens

In this study, a novel Lactococcus garvieae B301 was isolated from the intestinal tract of a healthy piglet. L. garvieae B301 was tolerant to acid pH, simulated gastric and small intestinal transit juices, indicating that it was capable of surviving in the gastrointestinal tract. L. garvieae B301 was safe and beneficial to broilers, as broiler chickens supplemented with L. garvieae B301 had lower diarrhoea incidence and mortality than the Control. Moreover, supplementation of broiler diets with L. garvieae B301 resulted in an increase in body weight and the number of caecum lactic acid bacteria and Bifidobacterium spp., and decrease in feed‐to‐gain ratio and the number of caecum coliforms. It also had a positive effect on the thymus index and bursa of Fabricius index and enhanced serum levels of immune globulins. All these results showed that L. garvieae B301 could enhance the growth performance of broiler chickens and improve their health. Thus, L. garvieae B301 could be a promising feed additive for broiler chickens.     

Effect of administration of acid‐ and bile‐tolerant lactobacilli on pigs intestinal microbial population

The effects of the administration of four Lactobacillus strains as probiotics on the constitution of microbial populations in the intestine of pigs were investigated by using a litter of pigs. The experimental group was fed a diet blended with the freeze‐dried powder containing lactobacilli at a concentration of 0.2% (W/W). After 4 weeks of probiotics administration, the total viable count of anaerobes in the feces was not significantly different between the pigs fed a diet supplemented with probiotics and the pigs given the non‐supplemented diet. However, viable counts of eubacteria were significantly higher (P < 0.01) in the feces of pigs fed a diet supplemented with probiotics than in the pigs given the non‐supplemented diet. Conversely, viable counts of clostridia were significantly lower (P < 0.01) in the feces of pigs fed a diet supplemented with probiotics than the pigs given the non‐supplemented diet. The total volatile fatty acid concentrations in the feces of pigs that were given a diet supplemented with probiotics were significantly lower (P < 0.05) than those given the non‐supplemented diet. Further, the molar proportion of n‐butyric acids in the feces of pigs that were given a diet supplemented with probiotics, was significantly lower (P < 0.05) than those given the non‐supplemented diet.     

益生菌调节肠道菌群及免疫调节作用机理

益生菌是指改善宿主微生态平衡而发挥有益作用,达到提高宿主健康水平和健康状态的活菌制剂及其代谢产物。本文以乳酸菌、双歧杆菌和芽孢杆菌等几种常见的食用或饲用益生菌为对象,论述其调节肠道菌群和免疫调节作用的机理。     

Effect of organic acids or probiotics alone or in combination on growth performance,nutrient digestibility,enzyme activities,intestinal morphology and gut microflora in broiler chickens

A feeding trial was conducted to determine the effect of organic acids or probiotics alone or in combination on growth performance, nutrient digestibility, enzyme activity, intestinal morphology and gut microflora in broiler chickens (Ross308). A completely randomized design was used, with 1,440 broiler chicks across four treatments and five replications of 72 chicks each. The chicks in the control treatment were fed on a control diet (CD), whereas for the other treatment groups, the CD was supplemented with 0.2 g/kg organic acids (CDOA), probiotics (CDP) or a combination of organic acids and probiotics (CDOAP). All the chicks were fed ad libitum during the feeding trial throughout 35 days. A total of 20 chicks were randomly allotted to individual metabolic cages to measure the nutrient digestibility (35–42 days) and the digestive enzyme activities (42 days). The intestinal morphology and gut microflora of 80 chicks were examined at the end of experiment. There were no significant (p > .05) differences in the feed intake, body weight gain or feed conversion ratio of the chicks across the four dietary treatments. The crude fibre digestibility was significantly increased in chicks fed on CDOA or CDOAP relative to CD (p < .05). Nutrient utilization, in terms of digestive enzyme activities and excreta thermal property, was unchanged by any supplementation. The chicks fed on the CDOAP had significantly higher duodenal villi height and crypt depth than the chicks fed on CDOA (p < .05). This dietary treatment dramatically improved gut microflora by decreasing the population of Escherichia coli and increasing the Lactobacillus spp.:E. coli ratio. Based on our investigations, supplementation of organic acids and probiotics in chick diets can increase the ability to digest crude fibre and villus height and decrease intestinal E. coli without impairing growth performance.     

乳酸在奶牛体内的代谢途径及其对奶牛健康影响的研究进展

乳酸（lactic acid）是奶牛瘤胃内重要的中间代谢产物,合理的调节乳酸代谢特征、充分利用及发挥乳酸的有益功能对奶牛健康生产具有重要意义。文章介绍了乳酸的合成途径及主要产酸菌、乳酸的代谢途径及主要利用菌、乳酸在奶牛瘤胃内的代谢方式及影响其代谢的因素,详细阐述了乳酸产生菌与利用菌对乳酸代谢调节的影响,同时介绍了植物提取物对乳酸代谢调节作用及乳酸代谢调节对奶牛胃肠道菌群、泌乳性能和乳房炎的影响。为进一步了解乳酸对奶牛健康的作用机制及相关植物活性物质在生产实践中的应用提供理论依据,为解决高精料饲粮引起的奶牛酸中毒的预防与治疗提供新思路。     

Effect of probiotics on blood fatty acid metabolism during the late middle stage of fattening period in Japanese Black cattle

This study was conducted to investigate the effects of probiotics administration on fatty acid metabolism in Japanese Black cattle as per changes in blood fatty acid concentrations and blood biochemical tests. Eighteen clinically healthy Japanese Black female fattening cattle bred on the same fattening farm were randomly classified into the probiotics administration group (n=9) or the control group (n=9). In the probiotics administration group, 50 g of probiotics were started per animal per day at the age of 18 months, and the administration period was 2 months from the start date of the study. Blood was collected twice before starting the probiotics administration and at 2 months after starting the probiotics administration. In the probiotics administration group, palmitic, linoleic, arachidonic and α-linolenic acid tended to be higher at the end of the administration compared with those before probiotics administration. Additionally, as a result of multiple comparison test, monounsaturated fatty acids at Post was significantly higher, and the ω6 / ω3 ratio was significantly lower than in the control group. Vitamin A, E and albumin were significantly higher at the end of the administration than in the control group. In this study that administering probiotics to Japanese Black cattle in the late middle stage of fattening period did not have a significant effect on fatty acid metabolism during feed digestion and absorption, but suggested that may alter some blood fatty acids concentrations.     

复合益生菌对肉鸡肠道微生物区系的影响

【目的】 探究干酪乳杆菌、嗜酸乳杆菌、乳双歧杆菌组成的复合益生菌对黄麻肉鸡生产性能及肠道微生物区系的影响, 为复合益生菌在肉鸡生产中的应用提供理论基础。【方法】 将200只1日龄雄性黄麻肉鸡随机分为2组, 每组5个重复, 每个重复20只。复合菌制剂(干酪乳杆菌∶嗜酸乳杆菌∶乳双歧杆菌=1∶1∶2)按1%比例补充于益生菌组肉鸡的饮用水中, 以正常饮水的肉鸡为对照。在42 d时以重复为单位测定肉鸡的生长性能指标, 并进行肠道菌群高通量测序分析。【结果】 与对照组相比, 益生菌组肉鸡的平均日增重显著增加(P<0.05), 平均日采食量、屠宰率和全净膛率增加, 料重比降低, 但差异不显著(P>0.05);益生菌组肠道菌群的OTU总数及回肠的Sob、Chao、Pd、Shannon、Shannoneven指数均降低, Simpson指数升高, 差异均不显著(P>0.05);厚壁菌门在肉鸡肠道中丰度最高, 具主体地位。较对照组而言, 益生菌组回肠中未见梭菌属, 厚壁菌门和乳球菌属的丰度均显著或极显著增加(P < 0.05; P < 0.01), 放线菌门和葡葡萄球菌属的丰度均显著或极显著降低(P < 0.05; P < 0.01), 盲肠中毛螺菌科的丰度显著增加(P<0.05)。【结论】 复合益生菌可通过增加肉鸡回肠乳杆菌属丰度、降低病原菌丰度来改善肠道菌群的组成、功能和多样性; 同时通过增加盲肠毛螺菌科丰度来提高肠道发酵降解非淀粉多糖的能力, 进而提高饲料利用效率, 促进肉鸡生长。     

马属动物肠道微生物的研究进展

马属动物肠道中的微生物对其消化具有重要的作用,尤其是盲肠中的微生物,它的数量和种类影响机体对营养物质的消化利用,文中主要论述了马属动物肠道微生物在机体的定殖发展的过程以及各种微生物对机体的主要作用,并对粗饲料对肠道菌群的影响进行了综述。     

乳酸菌对猪肠道屏障功能的调节作用及其机制

乳酸菌作为最重要和安全性最高的益生菌来源已被广泛关注,而乳酸菌调控人和动物肠道屏障功能已成为研究的热点,大量的体内外研究表明乳酸菌发挥益生作用的主要机制是通过调节肠道屏障功能实现的.相对于啮齿动物而言,乳酸菌在猪上的应用研究报道很多,对肠黏膜屏障功能的作用研究较少.这些研究尚未触及到乳酸菌作用机制的本质.猪肠道环境的复杂性,使得对乳酸菌调节肠道屏障功能机制的深入认识比较困难.近年来,基因组学、蛋白质组学和代谢组学的发展,为从体内试验的角度解析乳酸菌的确切作用机制提供了新的认识和研究手段.本文综述了乳酸菌对猪肠道屏障功能的调节作用,以期能帮助对乳酸菌的深入认识和科学应用.     

植物粉剂对肉鸡生长性能、肠道菌群数量和肌肉脂肪酸的影响

文章旨在评估植物粉剂(大蒜粉和石莲花粉)对1～42?d肉鸡生长性能、肠道菌群和肌肉脂肪酸组成的影响.试验选择平均初始体重为(48.33±0.47)g的1日龄商品肉仔鸡640只,随机分为4组,每组5个重复,每个重复32只.对照组饲喂基础日粮,药物组肉鸡饲喂基础日粮,但通过饮水补充2?mg/L维吉尼亚霉素水溶剂,大蒜粉组肉...     

In Vitro Metabolism of Fumonisin B1 by Ruminal Microflora

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium moniliforme and F. proliferatum. Little is known of its metabolic fate after oral ingestion in ruminants, but these animals are reported to be tolerant towards FB1. The metabolism of this mycotoxin was evaluated following incubation (1 g/ml) in ruminal fluid for up to 72 h, in the presence or absence of alfalfa as a substrate for microbial growth, using a model rumen (sealed flask, anaerobic conditions, exclusion of light, gentle agitation, 39°C). The decrease in FB1 concentration and the production of short-chain fatty acids were determined. FB1 had no effect on SCFA production. After 72 h incubation, FB1 depletion was 12% and 18% in samples with and without alfalfa, respectively. No hydrolysed metabolites (aminopolyols or aminopentol) were detected. These results indicate that FB1 is poorly metabolized in the rumen and suggest that such metabolism is not the cause of the tolerance to this toxin displayed by ruminants.     

The effects of benzoic acid supplementation on the performance of broiler chickens

To determine the efficiency of benzoic acid, a feeding experiment was carried out with 240 one‐day old ROSS 308 cockerels. Birds were divided into three dietary treatments: I (C) – no additives, II (B1) – 0.1% inclusion of benzoic acid, III (B2) – the inclusion of 0.2% benzoic acid. The performance results were similar in birds fed the control diet and the diet with 0.1% of benzoic acid. The dietary inclusion of benzoic acid at 0.2% depressed the growth of broiler chickens (p < 0.05). The dry matter of the digesta increased in the crop and caeca after benzoic acid supplementation. The pH of the caecal contents decreased following benzoic acid supplementation and was the lowest in the B2 group. No differences were found in the pH of the crop, ileal, gizzard digesta and rectum content. Lactic acid bacteria populations were the lowest in the caeca of the B1 group (p < 0.05). Coliform bacteria decreased in the caeca contents following increased benzoic acid supplementation.