黄曲霉毒素中毒的防治

黄曲霉广泛存在于自然界,通常寄生于玉米、小麦、大麦、燕麦、稻米、花生、豆类、棉籽和鱼粉及肉制品上,是粮食、饲料的主要真菌之一.粮食和饲料在收获、加工和贮存时处理不当,很容易被黄曲霉侵染.黄曲霉能迅速大量繁殖,并产生黄曲霉毒素.各种动物都可以发生黄曲霉毒素中毒,以雏鸡、雏鸭、猪较多发.     

猪黄曲霉毒素中毒防治

1．1临床类型临床上可分为急性、亚急性和慢性中毒三种类型,其中以亚急性较为常见。急性病例：中毒多发生于食入被污染的饲料后1～2周左右,猪多在运动中死亡或发病后2d内死亡。     

黄曲霉毒素中毒及其预防

1.黄曲霉毒素中毒的由来黄曲霉毒素是某些霉菌,主要是黄曲霉及寄生曲霉产生的毒素,目前已知有16种不同的结构,其中以黄曲霉毒素 B_1最为常见,毒性也最强。1960年在英国的火鸡中首先发现黄曲霉毒素中毒。当时大约有10万只火鸡发病死亡,由于未知病因,称为“火鸡 x病”。随后的研究,很快就证明是由于饲喂了从巴西输入的     

肉鸡黄曲霉毒素中毒的防治

肉鸡黄曲霉毒素中毒在肉鸡饲养中时有发生，日常饲养中的主要中毒原因是误用霉烂变质带有黄曲霉毒素的饲料及饲料原料而造成的，易变质带黄曲霉毒素的饲料原料主要以豆饼（粕）、花生饼（粕）、棉粕等为主，变质的原因主要是饲料原料受潮而发生霉变生成黄曲霉毒素。一、症状病鸡精神沉郁，闭目无神，羽毛蓬乱，部分病鸡食欲减少，有的鸡中毒后头向侧歪，身体转圈，站立不稳，张口伸颈呼吸，颈部脊椎手摸僵硬，粪便稀薄呈水样，最后衰竭死亡，死鸡全身僵直坚硬。食量越大，越壮的鸡死亡时间越快。二、剖检变化经剖检发现，肝脏边缘钝厚肿大，…     

如何防治猪黄曲霉毒素中毒

<正>黄曲霉毒素主要引起动物干细胞变性、坏死、出血,胆管和干细胞增生。临床上以全身出血、消化机能紊乱、腹水、神经症状等为特征。黄曲霉菌广泛存在于霉变花生、玉米及谷物中,大多数黄曲霉是不产     

奶牛黄曲霉毒素中毒的防治

黄曲霉毒素中毒是一种真菌毒素中毒性疾病,属人畜共患,其造成的危害和影响非常严重.该毒素是剧毒物质,其毒性相当于氰化钾的10倍、砒霜的68倍,其中幼小动物对该毒素最为敏感,目前已发现的黄曲霉毒素有20种,其中B1、B2、G1、G2毒素的毒力最强,尤以B1毒素毒力为甚.黄曲霉毒素可致癌,动物在饲喂含该毒素的饲料后,其产品如奶等含有黄曲霉毒素,会对人体健康产生影响.奶牛长期或大量摄食经黄曲霉、寄生曲霉污染的饲料可导致黄曲霉毒素中毒.其临床特征是消化机能紊乱、神经症状和流产;剖检见肝变性、坏死和纤维化硬变.     

猪黄曲霉毒素中毒及防治

本文分析育肥猪养殖过程中黄曲霉毒素中毒的原因,并针对性地提出解决方法及措施,供同仁参考和借鉴.     

家禽黄曲霉毒素中毒的防治

黄曲霉毒素是黄曲霉的一种代谢产物 ,目前已发现黄曲霉毒素及其衍生物有 2 0种 ,并以毒素Ｂ1、Ｂ2、Ｇ1和Ｇ2的毒力最强。黄曲霉菌最易感染一些植物种子 ,包括花生、玉米、黄豆、棉子等。如果在收获、加工和贮存过程中处理不当 ,脱水不良 ,黄曲霉菌就会大量生长并产生黄曲霉毒素 ,家禽中毒多是由于应用了被感染的种子及由其制作的饲料所致。黄曲霉毒素是一种肝毒物质 ,鸡中毒以肝脏受损 ,全身性出血、腹水、消化机能障碍和神经症状为特征。症状　幼鸡、幼鸭一般为急性中毒。幼鸡多发生于 2～ 6周龄 ,症状有食欲不振 ,羽毛松乱 ,翅下垂 ,饮水…     

肉鸡热应激及防治

我国南方大部分地区夏季气温较高,高密度饲养造成肉鸡的热应激发生普遍,导致生产性能降低,免疫机能下降,发病死亡率升高,给肉鸡饲养业带来很大经济损失。 1 原因分析 肉鸡体表羽毛丰厚,皮肤没有汗腺,生长迅速,新陈代谢旺盛,体温较高。一般认为,肉鸡生长的适宜温度为15.6～21.2℃,在适温范围内,鸡体代谢产热主要靠物理方式经幅射、传导和对流散失,其余经呼吸道途径散发,产热和散热基本保持平衡,鸡的体温不升高,肉鸡表现生长速度快,饲料利用率高,死亡率低。环境温度在适温区以外,肉鸡主要依靠化学方式调节体温,首先表现体温的升高或降低,其次饲料利用率和生产性能下降。环境温度超过28℃时,肉鸡开始出现热应激反应,表现张口呼吸,饮水量显著增加。超过30℃,鸡体温度随着环境温度的升高而上升。超过38℃就有死亡的危险。 2 临床症状 2.1 生理变化 肉鸡精神不振,体温升高,呼吸急促,经常蹲伏在地上或网上,两腿叉开,翅膀下垂,冠及肉髯苍白,采食量明显减少,饮水增加,饲料转化率降低,生长速度变慢,发病率及死亡率上升。 2.2 血液变化 血液变稀,红细胞压积、血红蛋白及其它固形物浓度相应减少,CO2分压下降,pH值升高,表现明显的呼吸性碱中毒。血钾、血钙和血磷浓度显著下降,氢离子和碳酸氢根离子浓度也明显下降。血糖降低,血清总蛋白、球蛋白和白蛋白均显著下降,血脂无明显变化。血清尿酸水平升高,血浆甘油三酯水平显著升高。     

乳酸杆菌对黄曲霉生长抑制的研究

从7株分离自健康奶牛粪样的乳酸杆菌及鸡源乳酸杆菌B30中筛选对黄曲霉生长有明显抑制作用乳酸杆菌,采用混悬涂布法测试这几株乳酸杆菌对黄曲霉孢子萌发的影响.结果显示,鸡源乳酸杆茵B30和牛源乳酸杆菌BN3均能较明显的抑制黄曲霉生长,并且对黄曲霉的孢子萌发有抑制作用.通过生化鉴定和16SrRNA序列分析,鉴定两菌株均为植物乳酸杆菌.     

Disseminated Aspergillus flavus infection in broiler breeder pullets

Increased morbidity and mortality occurred in a 5-wk-old broiler breeder replacement pullet flock. The affected broiler pullet flock was housed on the first floor of a two-story confinement building. Mortality increased to 0.1%/day compared to the flock on the second floor, which had mortality levels of less than 0.01%/day. Clinical signs in the affected chickens included inactivity, decreased response to stimuli, and anorexia. No respiratory or neurologic signs were observed. On necropsy, affected pullets were dehydrated and emaciated and had disseminated variably sized single or multiple heterophilic granulomas that contained intralesional septate and branching fungal hyphae. Lesions were extensive around the base of the heart in the thoracic inlet and in the kidneys. Other affected organs included eyelid, muscle, proventriculus, ventriculus, intestine, liver, spleen, lung, and heart. Aspergillus flavus was cultured from the visceral granulomas. The source of flock exposure to the organism was not determined.     

抑制黄曲霉乳酸菌的筛选与鉴定

黄曲霉是玉米(Zea mays L.)青贮过程的主要污染物之一,本研究旨在从玉米青贮饲料中分离筛选出能够抑制黄曲霉菌生长的乳酸菌,为改善和提高青贮饲料品质提供优良菌种。本试验采用双层平板法,从玉米青贮饲料中筛选抑制黄曲霉的菌株,并对其进行生理生化鉴定及同源性分析,构建系统发育树,明确各菌株的分类地位。结果表明：从青贮发酵不同阶段筛选得到50株乳酸菌,其中有7株乳酸菌对黄曲霉有明显抑制作用(P<0.05),抑菌圈直径均大于3.60 cm,均为革兰氏阳性同型发酵乳酸菌,7株乳酸菌中Q39(49.40%)和Q40(49.60%)抑菌效果最好,抑菌圈直径为4.15 cm和4.17 cm,显著高于其他5株乳酸菌(P<0.05);菌株Q11,Q28,Q40,Q44与22种碳水化合物作用均呈阳性,菌株Q39和Q49与鼠李糖作用呈阴性,与松三糖反应呈弱阳性,菌株Q13相较于其他6株菌株对于碳源的利用情况较弱;经16S rDNA鉴定确定菌株Q39和Q49为植物乳杆菌,Q11,Q13,Q29,Q40,Q44为戊糖乳杆菌。菌株Q39和Q40可作为全株玉米青贮发酵的备选添加菌株。     

Fluorometric evaluation of aflatoxigenic strains of the molds Aspergillus flavus and Aspergillus parasiticus after culture in liquid medium

The production of aflatoxin (AF) by A. flavus and A. parasiticus strains originating either from the Czechoslovak collection or isolated from feed mixtures and from peanut samples was determined following their cultivation in liquid synthetic GV medium. Their aflatoxicogenic effects were estimated from fluorescence of the GV medium after its application onto filter paper or by determining emission intensity of chloroform extracts of the medium in a fluorescence spectrophotometer. In extracts with emission intensity from 0 to 880 at two sensitivity settings of the device, AFB1 concentration was found to be in the range from 0 to 54.5 mg.l-1 when determined by means of the RIA method. Emission intensity was not in a linear relationship with AFB1 level in the medium and was higher than at a corresponding concentration of AFB1 standard solution. The fluorometric method is many times more sensitive than visual assessment of medium fluorescence on filter paper, which, for its part, was more reliable than the estimation of fluorescence following the cultivation of strains with low AF production on solid APA medium. This and other screening methods are surpassed by the employed fluorometric method as far as the sensitivity and saving of time are concerned, especially when medium extract is used for further more precise analysis.     

禽源烟曲霉菌和黄曲霉菌的分离鉴定及几种中药抑菌作用研究

【目的】对保定市临床真菌感染病鸭进行菌株分离鉴定,并筛选分离菌株的体外抑菌药物。【方法】通过形态学观察、PCR扩增、测序及动物回归试验对菌株进行鉴定,并采用微量稀释法测定最小抑菌浓度(MIC)及体外药敏试验统计菌落数量和直径来探究石菖蒲、黄柏、决明子、苦参、辣蓼、白头翁和蒲公英对烟曲霉菌(Aspergillus fumigatus)和黄曲霉菌(Aspergillus flavus)的体外抑菌活性。【结果】成功分离到烟曲霉菌和黄曲霉菌。动物回归试验结果显示,雏鸡出现与病鸭相似的症状,剖检可见肝脏长出灰白色结节,且病变组织出现肉芽肿病变,说明2种病原菌均可使雏鸡感染。烟曲霉菌MIC₈₀结果显示,石菖蒲、黄柏、决明子和苦参MIC₈₀分别为8、16、32和64μg/μL,辣蓼、白头翁和蒲公英均为128μg/μL;黄曲霉菌的MIC₈₀结果显示,石菖蒲、决明子和黄柏MIC₈₀分别为8、16和32μg/μL,苦参和辣蓼均为64μg/μL,白头翁和蒲公英均为128μg/μL。体外药敏试验结果显示,在石菖蒲浓度为16...     

Aspergillus flavus keratomycosis in a cat treated with topical 1% voriconazole solution

An 8-year-old male castrated Domestic Short-haired cat was examined for a 1-week history of blepharospasm and mucoid ocular discharge OS. Examination revealed ulcerative keratitis with stromal loss, stromal infiltrate, corneal edema, perilimbal vascularization and miosis. Cytology of the cornea revealed multiple dichotomously branching, septate fungal hyphae and severe, predominantly neutrophilic inflammation. PCR of the cytology samples confirmed the presence of Aspergillus flavus while fungal and bacterial cultures were negative. Treatment with topical 1% voriconazole solution was successful in resolving the keratomycosis.     

一例雏鸭病毒性肝炎与黄曲霉菌病混合感染的诊治与体会

本文对华北地区某养鸭户发病的樱桃谷肉鸭苗现场调查、临床表现和剖检变化,以及实验室检测结果,最后诊断为肉雏鸭病毒性肝炎和曲霉菌混合感染。通过采取一系列应急措施,有效控制了疫情。     

Cold-induced ascites in broiler chickens and its improvement by temperature-controlled rearing

Pulmonary hypertension syndrome (PHS), also known as ascites, in broiler chickens prevailed in the local area of Ibaraki prefecture, Japan, and was investigated epidemiologically, serologically, and pathologically. PHS developed in chickens older than 35 days of age when rapid increase of body weight started. Approximately 90% of affected birds were males, in which weight increase was greater than in females. Serologic test revealed that PHS broilers had an increase of hematocrit value. Pathologic studies indicated that the heart of affected birds had an obese-induced pressure and cold exposure triggered congestion in the right ventricle/cava and an increase in peritoneal fluid. These changes were consistent with the previous reports of PHS, so we designed the experiment of effects on cold-induced PHS birds in a temperature-controlled house. After the 10 PHS birds at 55 days were reared for 14 days in a temperature-controlled house at 20 +/- 5 C, ascites disappeared in eight birds and hematocrit values decreased to normal range in nine birds. Our finding indicated that temperature-controlled environment may be one solution to reduce mortality in PHS birds.