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产蛋量是衡量蛋鸡和种鸡养殖经济效益的重要指标。然而近年来,鸡产蛋下降征候群已成为导致鸡产蛋量下降的重要疾病,因而倍受养殖业主的关注。鸡产蛋下降征候群是以引起鸡群产蛋量减 相似文献
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造成蛋鸡产蛋性能低下及产蛋量下降的因素较多,有疾病、营养、环境因素、应激及体重均匀度等。其中以传染性疾病的危害性最大,如鸡新城疫、传染性支气管炎、禽流感、减蛋综合征和传染性鼻炎等。因为传染病的发生必定要造成产蛋的减少,还可造成鸡只 相似文献
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<正>在自然状态下,引起鸡产蛋下降的因素很多,有疾病、光照、温度、空气、水质、体重均匀度及环境应激等。该病可使鸡产蛋率下降10%～30%,甚至达到40%,蛋的破损率达38%～40%,无壳蛋、软壳蛋达15%。病初产蛋异常,接着整群鸡的产蛋量突然下降,远远低于正常水平。发病2～3周时产蛋量降至最低点,最多时可下降50%左右,即使治愈,也难以完 相似文献
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蛋鸡产蛋下降综合症是由禽腺病毒引起的能使蛋鸡产量下降的病毒性传染病。病鸡没有明显的临床症状,而以产蛋量下降、蛋壳异常、蛋体畸形及蛋质低劣为特征。本病可使鸡群产蛋量下降20％～30％左右,在产蛋高峰期,产蛋量可骤然下降30％～40％甚至更多。 相似文献
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均匀度是指种鸡群中鸡生长发育的整齐度,它是种鸡育雏期、育成期一个很重要的技术指标,一般而言,均匀度低于75％,会造成种鸡不能适时开产、产蛋高峰迟、产蛋高峰持续周期短、整个鸡群产蛋量下降,良好的均匀度是提高种鸡生产性能的前提和保证。 相似文献
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鸡产蛋下降综合征又称减蛋综合征,是由产蛋下降综合征病毒引起的一种传染病,被列为国家二类动物疫病。其以蛋鸡产蛋量下降、产畸形蛋、褪色蛋和劣质蛋为主要特征,该病严重危害我国养鸡业的发展。现总结了鸡产蛋下降综合征的临床症状和病理变化,并结合目前蛋鸡生产实际提出了该病的预防措施。 相似文献
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1蛋鸡减蛋综合症又叫产蛋下降综合症,是由病毒引起的一种能使产蛋率下降的传染病。病初产蛋异常,出现软壳蛋、畸形蛋或蛋壳的颜色变浅。接着整群鸡的产蛋量突然下降,远远低于正常水平。 相似文献
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Beran GW 《Preventive veterinary medicine》2008,86(3-4):198-207
When early people made their appearance, zoonotic infectious diseases were already waiting, but epidemic diseases did not appear in human history until people began to live in large numbers under conditions of close contact, mainly during the last 10,000 years. Disease has decimated urban populations, conquered armies, and disrupted society. The focus here is on (1) the plague of Athens and the Black Death; (2) smallpox, influenza, and rabies; (3) avian influenza prion diseases, and foot & mouth disease; and (4) emerging and re-emerging diseases. All have veterinary public health associations. In Athens, Greece, in 430 BC, when the Spartans ravaged the countryside, hordes crowded into Athens so that orderly movements, space in which to live, and adequate supplies of food became impossible. Crowding of any population fosters disease transmission; chaos and disorder enhance it all the more. Out of northern Egypt came a terrible plague from across the Mediterranean Sea. The identity of the plague of Athens remains unsure, but the well-considered conclusion is Rift Valley Fever, a mosquito borne, viral zoonosis. The Black Death, also called the Plague, raged in Asia for centuries. In 1347, the Black Death was brought by a ship out of Asia to Sicily. The scenes of devastation were repeated throughout Europe, with 90% or more of the people dying in city after city. Influenza, too, has been a cause of periodic human epidemics, but the great pandemic of influenza occurred in the last months of World War I. In the years of highest occurrence, more than half the world's population became clinically infected. If veterinary public health had been born earlier, it could have led to elucidating the epidemiology of influenza and the plagues of Athens, Europe, and Asia. In turn, smallpox had also caused continual tragedy. In 1796, Edward Jenner began to harvest pustules of cowpox from children or infected cows and inject them into susceptible children. In 1980, the World Health Organization declared that smallpox had been eliminated from the world. Rabies, though, still strikes terror. A number of animal diseases, broadly termed emerging and re-emerging diseases, need surveillance because they have the potential to impact human health. From late in 2003 to 2007, the highly pathogenic H5N1 influenza virus in poultry infected at least 121 people and caused 62 deaths in four countries. The prion diseases, too, all have very high numbers in concentrated contacts. To control these diseases, veterinary public health is essential, with diagnosis, epidemiological surveillance, clinical manifestations, and prevention as primary measures. 相似文献
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Dekker A Dercksen D Snoep J van Wuyjckhuise L 《Tijdschrift voor diergeneeskunde》2007,132(18):695-701
On 26th of july 2007 a new case of bluetongue was notified in the Netherlands and on 2nd of august 2007 foot-and-mouth disease was diagnosed in Surrey, England, which raised the threat of having both infections simultaniously in one area. Bluetongue and foot-and-mouth disease have a different pathogenesis, but symptoms may resemble each other at a later stage of infection. The pathogenesis and possible clinical symptoms of both infections are discussed and illustrated with pictures. 相似文献
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在动物的异常行为中以刻板行为最为常见,而咽气癖又是马最常见的口部刻板行为之一。作者就咽气癖在生理方面和心智方面对马体产生的影响、行为基础、诱因的研究进展及常见的防治措施进行综述。 相似文献
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