Prevalence and Distribution of Animal Trypanosomosis on Buvuma Islands in Lake Victoria,Uganda

Tropical Animal Health and Production -     

畜禽基因图谱研究进展

本文对基因图谱种类、畜禽基因图谱研究的方法、现状和研究进展、基因图谱在畜禽遗传育种中的应用进行了综述,并阐述了畜禽图谱构建的意义.     

畜禽基因图谱研究进展

本文对基因图谱种类、畜禽基因图谱研究的方法、现状和研究进展、基因图谱在畜禽遗传育种中的应用进行了综述，并阐述了畜禽图谱构建的意义。     

(犭霍)(犭加)狓非洲森林中最神秘的动物

20世纪初期,英国探险家亨利·约翰斯顿在非洲东北部的原始森林探险,发现了一种名叫(犭霍)(犭加)狓的奇怪动物.从体形上看,与马十分相似,它腿上的黑白条纹很容易让人误认为是斑马.所以在发现初期,(犭霍)(犭加)狓就一直被认为是属于斑马的一个亚种,后来才最终认定,它属于偶蹄目长颈鹿科,是长颈鹿的唯一近亲.(犭霍)(犭加)狓被发现后的半个世纪里,人们对它的了解寥寥无几,甚至一度被认为已经灭绝.原因是这种动物生性胆小,又始终保持着警戒,甚至每天只睡1个小时,人们一直难以发现和接近.直到1959年8月,人们才再次发现这种动物,并开始对其进行人工饲养、研究和保护.     

Rinderpest Vaccination and the Incidence and Development of Trypanosomosis in Cattle

An investigation was made into whether recent vaccination of cattle with tissue culture rinderpest virus would cause immunosuppression and lead to more frequent or more severe infection with trypanosomes in animals grazing in tsetse-infested areas. Herds of cattle on Galana Ranch in Kenya were divided, with approximately half of each herd being vaccinated with tissue culture rinderpest virus strain Kabete O, while the rest remained unvaccinated. The herds were then exposed to the risk of natural infection with trypanosomes on the ranch. Three experiments were performed during different seasons. Infections with Trypanosoma congolense and Trypanosoma vivax were frequently detected but there was no evidence that vaccinated animals were more likely to acquire trypanosome infections or to show a more severe disease than unvaccinated cattle. It is concluded that tissue culture rinderpest vaccine does not cause immunosuppression and can safely be used in cattle likely to be exposed to tsetse flies and trypanosomosis.     

畜禽数量性状座位(QTL)定位研究进展

综述了畜禽数量性状座位(QTI)定位的原理、基本策略、统计分析方法以及对未来的展望.     

基因图谱的构建及其在动物遗传育种中的应用

本文阐述了遗传图谱、物理图谱的概念，着重介绍了利用人这标记构建遗传图谱和物理图谱的方法，并阐述了基因图谱在家畜育种中的应用。     

Farmers' Perceptions of the Impacts of Tsetse and Trypanosomosis Control on Livestock Production: Evidence from Southern Burkina Faso

Interviews with all the households in the Agropastoral Zone (ZAP) of Yalé, southern Burkina Faso, were conducted in 1994 and again in 1997 to assess the impacts of a tsetse control programme implemented from 1994, using insecticide-impregnated targets and pour-on treatments of all cattle with deltamethrin 1%. In the absence of health and productivity monitoring, data were collected in single-visit surveys in order to generate quantitative estimates of relevant reproductive performance variables for cattle and to assess changes in the inputs used and outputs produced. The results indicate a 25% increase in herd size and an increase in the number of oxen from 0.1 to 1.1 per household; a reduction in mortality from 63.1% to 7.1% and reductions in the rates of abortions and stillbirth of 55.9% and 51.3%, respectively; and an increase in the rate of live births of 57.6% and in the milk yield from 0.2 to 2.2 litres/cow per day in the dry season. These results show the dramatic impacts that trypanosomosis control can have on Zebu cattle exposed to high tsetse challenge. Well-designed surveys can be a cost-effective way to obtain estimates of productivity impacts that can be used to simulate projections of herd growth and meat and milk production in herd models. While there are many confounding factors associated with farmers' perception of a gain in productivity, these estimates form a useful alternative to subjective assessments in modelling the economic benefits of tsetse and trypanosomosis control.     

Hepatitis E virus: Animal reservoirs and zoonotic risk

Hepatitis E virus (HEV) is a small, non-enveloped, single-strand, positive-sense RNA virus of approximately 7.2 kb in size. HEV is classified in the family Hepeviridae consisting of four recognized major genotypes that infect humans and other animals. Genotypes 1 and 2 HEV are restricted to humans and often associated with large outbreaks and epidemics in developing countries with poor sanitation conditions, whereas genotypes 3 and 4 HEV infect humans, pigs and other animal species and are responsible for sporadic cases of hepatitis E in both developing and industrialized countries. The avian HEV associated with Hepatitis-Splenomegaly syndrome in chickens is genetically and antigenically related to mammalian HEV, and likely represents a new genus in the family. There exist three open reading frames in HEV genome: ORF1 encodes non-structural proteins, ORF2 encodes the capsid protein, and the ORF3 encodes a small phosphoprotein. ORF2 and ORF3 are translated from a single bicistronic mRNA, and overlap each other but neither overlaps ORF1. Due to the lack of an efficient cell culture system and a practical animal model for HEV, the mechanisms of HEV replication and pathogenesis are poorly understood. The recent identification and characterization of animal strains of HEV from pigs and chickens and the demonstrated ability of cross-species infection by these animal strains raise potential public health concerns for zoonotic HEV transmission. It has been shown that the genotypes 3 and 4 HEV strains from pigs can infect humans, and vice versa. Accumulating evidence indicated that hepatitis E is a zoonotic disease, and swine and perhaps other animal species are reservoirs for HEV. A vaccine against HEV is not yet available.     

万古霉素在动物性食品中残留的风险评价

近年来万古霉素滥用导致耐甲氧西林葡萄球菌感染的发生率逐年增高。由于其在饲养过程中使用后可对动物有一定的促生长作用,动物性食品存在生产者非法添加的可能性。为了规范生产者行为、防范风险,本文对万古霉素存在风险加以评价并提出建议。     

从动物检疫票证的使用浅析当地畜牧发展趋势

动物检疫证明是一种行政许可证书,其使用情况直接映射出当地畜牧业发展现状,是动物、动物产品溯源的重要途径,是实行动物卫生监督风险评估的基础依据,对保障畜禽产品质量安全及防控重大动物疫病,指导当地畜牧业经济发展具有现实指导意义。本文将我市5年内动物检疫票证使用情况进行统计、分类汇总,从总体及分布两种情况科学分析了我市畜牧业发展现状、趋势及制约因素,并结合实际提出对策及建议,为有效保障我市公共卫生安全及畜牧业经济平稳较快发展提供科学理论依据。     

Impact of Tsetse Control on the Age-specific Prevalence of Trypanosomosis in Village Cattle in Southeast Uganda

The prevalence of trypanosomosis, mean packed cell volume and anti-trypanosomal antibody levels in village cattle of different age groups (<0.5 year, 0.5–2 years, >2–5 years and >5 years) in the areas with tsetse control were compared with those of corresponding age groups in areas without tsetse control in Tororo, southeast Uganda. The prevalence of trypanosomosis in cattle in the age groups of 0.5–2 years, >2–5 years and >5 years in the areas with tsetse control was significantly lower than in cattle in similar age groups in the areas without tsetse control (p<0.5). Trypanosoma vivax was the most predominant Trypanosoma species in the areas with tsetse control, while T. congolense was the most predominant species in the areas without tsetse control. The mean Trypanosoma antibody levels in cattle in the age groups <0.5 year, 0.5–2 years and >2–5 years in the areas with tsetse control were significantly lower than those of the similar age groups in the areas without tsetse control (p<0.5). The mean PCV values for cattle in the age groups 0.5–2 years, >2–5 years and >5 years from the areas with tsetse control were significantly higher than those of the similar age groups in the areas without tsetse control. Tsetse control appeared to have a considerable impact on the prevalence of trypanosomosis, distribution of Trypanosoma species, specific antibody levels and the packed cell volume of cattle in the different age groups.     

让畜牧业远离抗生素困扰

最近,人民网以《"超级细菌"哪里来》、《抗生素是把双刃剑》、《肉里咋吃出抗生素》为题发表《聚焦·直击抗生素滥用》系列报道,引起全国人民对畜牧业滥用抗生素的高度关注。我们畜牧业内人士都知道:饲料厂、养殖企业     

Trypanosomosis and reproduction: I. effect ofTrypanosoma vivax infection on the oestrous cycle and fertility in the ewe

Summary Ten West African Dwarf ewes were inoculated withTrypanosoma vivax and, at varying intervals, treated subcuratively with diminazene aceturate to maintain the infection. Soon after infection all ewes and anoestrus for 40 to 96 days and 5 died by day 110 post infection. Compared to control animals, infected ewes had prolonged low levels of plasma progesterone until recovery or death. However, no gross or histological lesions were detected in the endocrine or reproductive organs. Of the survivors, the 5 that were aparasitaemic subsequently became pregnant and had normal gestations.

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Tripanosomiasis Y Reproduccion: I. Effecto E Infecciones ConTrypanosoma vivax Sobre El Ciclo Estrual Y Reproduccion En La Oveja

Resumen Se inocularon 10ovejas West African Dwarf conTrypanosoma vivax y fueron tratadas periódicamente con dosis subcurativas de aceturato de diminazene, para mantener la infección. Pronto despues de la infección, todas las ovejas presentaron anestro por 40 a 96 dias y 5 murieron 110 dias después de la infección. Comparadas con controles, las ovejas infectadas presentaron niveles bajos de progesterona plasmática, hasta recuperación o muerte. Sin embargo, no se encontraron lesiones macroscópicas ni histológicas en los órganos reproductivos o endocrinos. De las sobrevivientes, las 5 que fueron aparasitémicas quedaron posteriormente preñadas y tuvieron gestaciones normales.

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Trypanosome Et Reproduction. I. Effet De La Trypanosomose AT. Vivax Sur Le Cycle Oestral Et La Fecondite Chez La Brebis

Résumé Dix brebis naines de l'Afrique de l'ouest ont été inoculées avecTrypanosoma vivax et, à intervalles variés, traitées avec e l'acéturate de diminazène à dose non curative pour maintenir l'infection. Peu après celle-ci, toutes les brebis ont présenté un anoestrus de 40 à 96 jours et 5 sont mortes le 110e jour après l'infection. Comparées aux animaux témoins, les brebis infectées ont montré des taux peu élevés et polonges de progestérone du plasma jusqu'à leur guérison ou leur mot. Cependant, aucune lésion importante ou histologique n'a été décelée dans les organes de reproduction ou endocriniens. Parmi les survivantes, les 5 qui n'étaient pas parasitées sont entrées en gestation et l'ont menée normalement à terme.