共查询到20条相似文献，搜索用时 546 毫秒
1.
2.
猪繁殖与呼吸障碍综合征的防控措施 《畜牧与饲料科学》2014,35(4):121-121
猪繁殖与呼吸综合征（PRRS）是由猪繁殖与呼吸综合征病毒（PRRSV）引起猪的一种繁殖障碍和呼吸道的传染病.介绍了贵州省铜仁市猪繁殖与呼吸综合征的病原、流行特点和临床症状,分析发病病因,并提出一系列综合性防控技术措施,以期为预防和控制该病提供参考. 相似文献
3.
4.
猪繁殖与呼吸障碍综合征（PRRS）是一种全球性疾病，它给养殖业造成巨大经济损失。据统计在美国每年因该病给养猪业造成的损失多达5．6亿美元。现已证实PRRS是由一种有囊膜的单链正股RNA病毒，即猪繁殖与呼吸障碍综合征病毒（PRRSV）引起的。传统的方法（如疫苗和动物隔离）并不能有效地控制该病，这使人们逐渐把目光聚焦到该病的净化上。了解PRRSV在动物间的传播规律以及阻止该病传播的措施对净化该病起至关重要的作用。本文综述了该病原的一些特点，包括病因学、临床症状、直接和间接传播途径，同时讨论了该病控制、预防和净化措施。 相似文献
5.
6.
朱连德 《动物科学与动物医学》2013,(1):86-89
猪繁殖与呼吸综合征（PRRS,猪蓝耳病）,在全球范围内持续给养猪业造成重大危害。人们一直在探索研究如何更好地控制乃至净化该病的方法,如：自家血清抗感染,自家疫苗免疫,商品疫苗免疫（包括灭活疫苗、弱毒疫苗）, 相似文献
7.
猪繁殖与呼吸综合征是一种引起母猪繁殖障碍和新生仔猪呼吸道症状的病毒性传染病,具有很高的传染性和死亡率,其几乎遍及世界所有养猪国家,给世界养猪业造成严重的经济损失.该病的病原为猪繁殖与呼吸综合征病毒,2006年在中国变异为高致病性猪繁殖与呼吸综合征病毒.疫苗免疫是防控该病的重要措施之一,其疫苗的研究也受到充分的重视.本文就近年来猪繁殖与呼吸综合征的灭活疫苗、弱毒疫苗和基因工程疫苗的研究进展作以综述. 相似文献
8.
猪繁殖与呼吸综合征（PRRS）是由猪繁殖与呼吸综合征病毒（PRRSV）引起的一种以母猪繁殖障碍、哺乳仔猪的高死亡率及呼吸症状为特征的传染病。该病1987年在美国首先发生，随后在世界各主要养猪国家流行。我国自1996年报道该病，现已在十几个省市发生，造成巨大的经济损失。[第一段] 相似文献
9.
猪繁殖-呼吸综合征（PRRS）是1987年首次在美国发现的一种新传染病。在80年代末至90年代初，该病曾席卷北美洲和欧洲，造成大量仔猪死亡与母猪流产及其繁殖率下降，经济损失十分惨重。郭宝清等（1996）首次从国内疑似PRRS感染猪群中分离出猪繁殖一呼吸综合征病毒（PRRS），从而证实了本病在国内的存在。在较长的一段时期内，对导致PRRS的病原缺乏足够的了解，直到1991年，设在荷兰Lelystad的中央兽医研究所首次分离到该病原——Lelystad病毒，即目前通称的猪繁殖一呼吸综合征病毒（PRRS），对该病病原学的研究才有了飞速的发展。今… 相似文献
10.
猪繁殖一呼吸综合征（PRRS）是1987年首次在美国发现的一种新传染病。在80年代末至90年代初，该病曾席卷北美洲和欧洲，造成大量仔猪死亡与母猪流产及其繁殖率下降，经济损失十分惨重。在较长的一段时期内，对导致PRRS的病原缺乏足够的了解，直到1991年，设在荷兰Lelystad的中央兽医研究所首次分离到该病原——Lelystad病毒，即目前通称的猪繁殖一呼吸综合征病毒（PRRSV），对该病病原学的研究才有了飞速的发展。郭宝清等（1996）首次从国内疑似PRRS感染猪群中分离出猪繁殖-呼吸综合征病毒（PRRSV），从而证实了本病在国内的存在… 相似文献
11.
选择中国大陆最早分离的H9N2亚型禽流感病毒(avian influenza virus,AIV)A/Chicken/Guangdong/SS/94(H9N2)(缩写为SS株)和1998年大流行时期分离的H9N2亚型AIVA/Chicken/Shanghai/F/98(H9N2)(缩写为F株)为研究对象,对其在SPF鸡体内的复制能力和传播途径特性比较后发现,F株在4周龄SPF鸡气管中的复制能力高于SS株,F株可以经气溶胶传播途径传播,SS株不能经气溶胶传播途径传播;利用反转录-聚合酶链反应(RT-PCR)方法获取F株和SS株的HA和NA基因的cDNA,序列分析得知,F株和SS株的HA和NA基因的同源性分别是96.6%和98.1%;HA基因的裂解位点氨基酸序列都是PARSSR↓GL,但有5个氨基酸的差异,即166位N(F)→D(SS)、198位A(F)→V(SS)、217位V(F)→I(SS)、335位G(F)→R(SS)、504位L(F)→S(SS);2株病毒的NA基因在63~65位都存在氨基酸缺失,但在NA基因红细胞吸附位点的氨基酸序列不同,分别是IKKDSRSG(F)和IKEDLRSG(SS)。F株和SS株的传播特性差异是否与其表面基因序列有关,有待进一步研究。 相似文献
12.
禽类的起源、演化及我国主要家禽品种类型与分布 总被引：1，自引：1，他引：0
家禽是重要经济价值动物.本文从禽类种群进化学说出发,简介了禽类的起源、演化、动物学分类和家禽的驯化(养)与品种的形成,并对我国主要家禽(鸡、鸭、鹅)地方品种和培育品种(配套系)的分布与类型作了描述,以期为研究我国家禽起源系统,保护与利用我国家禽品种,促进家禽生产可持续发展提供参考. 相似文献
13.
近年以来,由于市场因素的刺激,生猪的存养量大幅上升,再加上由于流通环节较多,流通非常频繁,流通距离越来越远。这对繁荣经济,增加养殖效益起了重要的推动作用,但也同时给疾病的感染和传播创造了有利条件,给猪病的防治带来了困难。有的猪场感染了传染病后,由于治疗不及时不得法,而造成了惨重的经济损失。2008年7月中旬,我街道一养猪户因盲目从外地购进中猪,发生猪病疫情,引起猪只连续死亡,造成一定的经济损失。根据流行病学、临床症状、剖检变化和实验室诊断,诊断该病为猪链球菌病和猪伪狂犬病混合感染,现报告如下。 相似文献
14.
１前言１．１鸡白冠病鸡白冠病是由卡氏住白细胞原虫寄生于鸡的红细胞和单核细胞而引起的鸡的贫血性疾病。吸血昆虫蚋和库蠓叮咬鸡引起传播，是主要的传播媒介，一般在夏末和秋季多发，由于夏季降雨量较大，部分沟渠积水，库蠓和蚋多孳生，因此在多雨水涝的年份发病率明显增高。１９９８年中国从南到北发生洪涝灾害，吸血昆虫的孳生格外严重，出现了一个白冠病多发年，而后两年发病稍轻，并有地区性，今年８月中旬以来白冠病的发病呈抬头趋势，有一定的死亡率，对蛋鸡产蛋率也会引起一定程度的降低，应引起养鸡户的重视。１．２鸡痘鸡痘也是… 相似文献
16.
17.
18.
Pinard CL Weiss ML Brightman AH Fenwick BW Davidson HJ 《American journal of veterinary research》2003,64(1):104-108
OBJECTIVE: To evaluate lactoferrin and lysozyme content in various ocular glands of bison and cattle and in tears of bison. SAMPLE POPULATION: Tissues of ocular glands obtained from 15 bison and 15 cattle and tears collected from 38 bison. PROCEDURE: Immunohistochemical analysis was used to detect lysozyme and lactoferrin in formalin-fixed, paraffin-embedded sections of the ocular glands. Protein gel electrophoresis was used to analyze ocular glands and pooled bison tears by use of a tris-glycine gel and SDS-PAGE. Western blotting was used to detect lactoferrin and lysozyme. RESULTS: Immunohistochemical staining for lactoferrin was evident in the lacrimal gland and gland of the third eyelid in cattle and bison and the deep gland of the third eyelid (Harder's gland) in cattle. Equivocal staining for lactoferrin was seen for the Harder's gland in bison. An 80-kd band (lactoferrin) was detected via electrophoresis and western blots in the lacrimal gland and gland of the third eyelid in cattle and bison, Harder's glands of cattle, and bison tears. An inconsistent band was seen in Harder's glands of bison. Lysozyme was not detected in the lacrimal gland of cattle or bison with the use of immunohistochemical analysis or western blots. Western blots of bison tears did not reveal lysozyme. CONCLUSIONS AND CLINICAL RELEVANCE: Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle. 相似文献
19.
Harvey CE 《Journal of veterinary dentistry》2002,19(4):186-195
Crown width, height and buccal surface areas were measured on heads or skulls of four dogs and four cats, and were compared with similar measurements on models of human dentition. Buccal surface area variability was greater in dogs and cats than in humans, and teeth of cats were smaller. Horizontal (gingival and occlusal halves) and vertical (mesial, middle, and distal thirds) buccal surface area variability was also greater in canine and feline teeth compared with human teeth. This increased variability suggests the need for testing of reliability and repeatability of scoring when using plaque and calculus indices based on horizontal or vertical segmentation. Buccal surface area variability between teeth also prompts questioning the validity of equal weighting of smaller, irregularly-shaped teeth when calculating a mean mouth score. Whether equal or more reliable results would be obtained from scores of whole teeth in comparison with segmentation indices used currently has yet to be determined. 相似文献
20.
Over a period of about 12 years, 30 abnormal Schistosoma mattheei cercariae were found among a total of approximately 2.8 million examined. Initially seven were recovered from about 1.02 million (0.0007%), which were examined individually while being counted with the aid of a stereoscopic microscope. Subsequently, on the strength of relatively high percentages of abnormal individuals recovered when counting cercariae that failed to penetrate into oxen, it appeared that the morphologically abnormal cercariae were unable to swim and would mostly sediment out of a suspension while most of the normal cercariae would remain swimming. This surmise is supported by recovery of 23 morphologically abnormal cercariae (0.001%) from about 1.8 million, by examining the sediment after the cercarial suspension had been left standing undisturbed in glass measuring cylinders. The abnormalities ranged from aberrant tails only (e.g. an underdeveloped tail, or different degrees of schism) or aberrant heads only, to abnormalities of both the heads and tails. A suggested schematic classification of abnormal cercariae is presented. A young, adult hamster was exposed to eight S. mattheei cercariae with complete schism of the shaft of the tail, by pipetting the cercariae onto the shaved abdominal skin of the anaesthetised animal. Two underdeveloped females were subsequently encountered in squash preparations of the liver when the hamster was killed for worm recovery 10 weeks after infection, thus showing that some of the abnormal cercariae were viable. A method is also described for killing and fixing cercariae while retaining some of the shining brilliance of live cercariae, without them becoming shrivelled, granular and semi-opaque, as occurs when cercariae die spontaneously or are killed with heat. This is apparently the first report of abnormal cercariae of S. mattheei. In addition, a method of concentrating abnormal cercariae after emergence from a snail, a schematic classification of abnormal cercariae and a method for killing and fixing cercariae while retaining much of the shiny brilliance of live cercariae are also reported for the first time as far as is known. 相似文献