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1.
Nicolas Rose Alain Abhervé-Guéguen Gérald Le Diguerher Eric Eveno Jean-Pierre Jolly Philippe Blanchard Aurélie Oger André Jestin François Madec 《Livestock Production Science》2005,95(3):177-186
The aim of this study was to determine the potential risk factors for PMWS at the individual pig level and assess the effect of the Pietrain paternal genetic background of the animals in a cohort study. The survey was set up in four PMWS-affected farms with 2 repetitions (batches) per farm. A representative sample of 60 pigs per batch, stratified according to the paternal genetic background (Pietrain: yes vs. no), was randomly selected after farrowing. The representative cohort was divided into 8 batches and the pigs were individually monitored from birth to slaughter. Survival analysis was used to determine the factors related to the time to PMWS. The litter-cluster effect was taken into account using the marginal Cox model (robust estimation of the covariance matrix) and the gamma shared frailty model which were compared.No protective effect of the Pietrain breed on the time to PMWS and the proportion of affected pigs in the offspring was found in this study. Piglets showing low circovirus type 2 (PCV2) titres at 7 weeks-old with no subsequent seroconversion and piglets from PCV2 negative sows were most likely to be affected by PMWS (HR=7.0 and 2.8, respectively). Active infection of the pregnant dams with parvovirus was related to an increased risk of PMWS in the offspring (HR=2.3). Neck injuries due to poorly performed injections in the dams were associated with an increased risk of PMWS with the marginal model (HR=2.1). Oxytocin injection (dams) during farrowing was protective against PMWS in the offspring (HR=0.6). 相似文献
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Hepatozoonosis caused by Hepatozoon canis is an important tick-borne disease of dogs in tropical and sub-tropical regions throughout the world. In the present study evaluation of blood samples collected from 225 dogs presented at Small Animal Clinics, GADVASU, Ludhiana, Punjab (India) was done for the presence of H. canis by PCR based assay targeting a portion of 18S rRNA gene. Of the total samples subjected to PCR, an amplicon of 666 bp was detected in 13.78% samples whereas, routine blood smear examination revealed gamonts in 5.78% samples. Furthermore, prevalence of H. canis infection was found to be significantly associated with season, being highest in summer and lowest in winter while other risk factors e.g. age, sex and breed showed non-significant association. In terms of various clinico-pathological parameters, significant drop in haemoglobin, total red blood cell count, packed cell volume and lymphocytes were recorded in positive cases whereas the total white blood cell count was non-significantly increased. The haematological alterations in the positive cases were lymphopenia, anaemia, thrombocytopenia, relative neutrophilia, neutrophilic leucocytosis, eosinophilia, monocytosis and lymphocytosis while the biochemical profile revealed hypoproteinemia and increased levels of blood urea nitrogen and creatinine (in positive cases) pointing towards renal failure. 相似文献
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Toxoplasma gondii is a widely distributed zoonotic protozoan parasite, which can affect most warm-blooded species. Some species of non-human primates (NHPs) are highly susceptible to T. gondii infection. The aim of the study was to determine the seroprevalence and risk factors associated with T. gondii infection in NHPs housed in zoos in Spain. Sera from 189 NHPs belonging to 33 species were collected in eight zoos. Additionally, 10 of the 189 animals were longitudinally sampled. Anti-T. gondii antibodies were detected in 48 NHPs (25.4%; confidence interval of 95% (CI95%): 19.2–31.6) using a modified agglutination test (MAT; cut-off = 25). Seropositive animals had titers of 25 (6.3%), 50 (8.3%), 100 (8.3%) and ≥500 (68.8%). Seropositivity was detected in 15 of the 33 species (45.5%). Of the 10 NHPs sampled more than once, two animals (one Barbary macaque [Macaca sylvanus] and one common chimpanzee [Pan toglodytes]) seroconverted along the study period, while one seropositive chimpanzee increased antibody titers over time. The Hominidae family (OR = 5.9; CI95%: 2.7–12.8) and sex (females) (OR = 2.1; CI95%: 1.1–4.1) were risk factors potentially associated with seropositivity to T. gondii. Our results evince a widespread circulation of T. gondii in NHPs in zoos in Spain, which may be of conservation concern. Control measures should be implemented to minimize the risk of exposure of these species to T. gondii. 相似文献
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天气衍生品是为了规避天气风险给天气敏感行业带来收入的不稳定性而兴起的创新型风险管理工具,其实质是通过衍生合约对天气风险进行分割、重组和交易的证券化产品。不同于传统金融衍生品,天气衍生品的价值取决于温度、湿度或降雨量等天气指数。本文在分析天气衍生品市场发展的基础上,重点探讨了最常见的天气期货和天气期权的运作机制及其精算定价。 相似文献
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Brucellosis is a highly contagious zoonotic infection affecting livestock and human beings. The disease has been reported worldwide except in few countries where it has been eradicated. The prevalence of brucellosis among cattle from 11 farms having a history of abortions was studied. A total of 481 samples comprising of blood, milk, vaginal swabs, vaginal discharges, placental tissues and fetal tissues were collected from 296 animals. Clinical samples were processed for the isolation of Brucella. Serum samples (n = 296) were tested by Rose Bengal Plate Test (RBPT) and indirect ELISA. A total of 90 (30.40%) and 123 (41.55%) samples were positive by RBPT and indirect ELISA, respectively. Also 27.02% samples were positive by both the tests. Brucella isolates (n = 8) were recovered from clinical samples using Brucella selective media. All the isolates demonstrated PCR amplification for the bcsp31 and IS711 genes. Amplification of Brucella abortus specific primer was demonstrated by all the isolates in AMOS PCR indicating isolates to be of either B. abortus biotype 1, 2 or 4. Risk factors for transmission of brucellosis among cattle population were studied by field surveys. It was observed that lack of awareness about brucellosis (OR = 8.739, P = 0.138) and inadequate floor space (OR = 0.278, P = 0.128) were crucial risk factors for transmission of bovine brucellosis. 相似文献
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DB102为一田间发现的三倍体水稻,利用它做母本与二倍体水稻中作59杂交,得到一个早世代(F2)稳定群体,通过微卫星分析发现,该群体中有一些微卫星位点发生了杂合性丧失,且至少6条染色体上发生微卫星位点杂合性丧失(loss of heterzygoisity LOH)可能有DNA序列变化。而微卫星位点的杂合性丧失又可能与该杂交组合早世代稳定有关。 相似文献
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Smallholder dairy herds around the Dar es Salaam region of Tanzania supply 86% of raw milk consumed by the city dwellers. Previous studies have indicated that clinical mastitis is an important disease affecting smallholder dairy cows and an 18-month questionnaire-based longitudinal field-study was conducted between July 2003 and March 2005 to elucidate risk factors associated with the incidence. A total of 6057 quarter-level observations from 317 lactating cows on 87 randomly selected smallholder dairy herds were analysed at the quarter and cow level using logistic and Poisson regression models, respectively. At the quarter level, the average incidence rate of clinical mastitis was 38.4 cases per 100 quarter-years at risk whereas at the cow level the incidence rate was 43.3 cases per 100 cow-years at risk. The incidence was significantly (P< or =0.001) associated with cow factors (body condition score, parity, stage of lactation, and udder consistency), housing (floor type) conditions and milking (cow and udder preparation) practices. It was concluded that the extrapolation of the classic ten-point mastitis control plan into smallholder dairy herds should be undertaken cautiously. An integrated approach to dairy extension should focus more on the creation of mastitis awareness among smallholder producers and on the improvement of animal nutrition and reproduction indices-factors that may also have a direct impact on milk yield. 相似文献
10.
Ramos Silva JC Marvulo MF Dias RA Ferreira F Amaku M Adania CH Ferreira Neto JS 《Preventive veterinary medicine》2007,78(3-4):286-295
From September 1995 to February 2001, blood samples were collected from 865 neotropical felids belonging to 8 different species. These animals were housed in 86 institutions located in 78 cities of 20 Brazilian states. Our goal was to identify the risk factors associated with sero-positivity to Toxoplasma gondii in captive neotropical felids from Brazil. All serum samples were tested by the modified agglutination test (MAT), using formalin-fixed whole tachyzoites and mercaptoethanol. For each animal an individual questionnaire was filled with questions about tattoo number, felid species, age, sex, origin, number of animals in the group, introduction of new animals in the group, time in the institution, eating meat previously frozen for a period <7 days in the last 6 months, eating meat of run-over or euthanized animals in the last 6 months, predation of rodents or birds in the last 6 months and presence of domestic cats near the enclosures in the last 6 months. The total sero-prevalence was 55% (95% CI: 52%, 57%). We estimated a prevalence of 46% (95% CI: 40%, 54%) for jaguarundi (Puma yagouaroundi); 58% (95% CI: 53%, 63%) for ocelot (Leopardus pardalis); 50% (95% CI: 45%, 56%) for oncilla (L. tigrinus); 54% (95% CI: 46%, 62%) for margay (L. wiedii); 12% (95% CI: 4%, 31%) for Pampas-cat (L. colocolo); 83% (95% CI: 65%, 93%) for Geoffroy's-cat (L. geoffroyi); 64% (95% CI: 50%, 68%) for jaguar (Panthera onca) and 48% (95% CI: 42%, 54%) for puma (Puma concolor). Multiple logistic regression was used to evaluate the association between the variables in the questionnaire and sero-positivity to T. gondii. We concluded that the independent risk factors for toxoplasmosis were: age >3 years (OR = 4.75 [2.75; 8.2]), eating meat previously frozen for a period <7 days (OR = 2.23 [1.24; 4.01]), and consumption of animals that were run-over or euthanized (OR = 1.64; [1.14; 2.37]). 相似文献