Risk factors to incidental leptospirosis and its role on the reproduction of ewes and goats of Espírito Santo state,Brazil

Ovine and caprine stockbreeding have been gaining attention in developing countries as an attractive investment. On these animals, infectious diseases of the reproductive tract, such as leptospirosis, can compromise the production leading to economic losses. The present study aimed to determine the risk factors associated with incidental leptospirosis and its influence on the reproductive parameters of ewes and goats of Espírito Santo state, Brazil. A total of 737 animals distributed on 24 herds/flocks were studied, and an overall prevalence of 10.9 % seroreactive animals was observed. Serogroup Icterohaemorrhagiae was the most frequent in goats (97.0 %) as well as in ewes (78.3 %). Regarding risk factors related to leptospirosis, the presence of waterholes and the semi-intensive breeding system were the most important associated to seroreactivity. Besides, there was an observed association between seroreactivity and reproductive failures (P?<?0.05). Moreover, seroreactive ewes (relative risk (RR)?=?1.3) and goats (RR?=?1.9) presented more chances to have abortions than seronegative animals. Furthermore, seroreactive ewes presented 11.6 more chances of having premature births when compared to the seronegative ones. It can be concluded that Leptospira infection, mainly those caused incidental strains (such as Icterohaemorrhagiae serogroup), is a significant factor to reduce the productivity of small ruminants’ herds/flocks in the studied region, and environmental measures must be considered on control programs.

     

Detection of Mycobacterium avium ssp. paratuberculosis in ileocaecal lymph nodes collected from elderly slaughter cows using a semi-nested IS900 polymerase chain reaction

The aim of this study was to investigate the occurrence of subclinical Mycobacterium avium spp. paratuberculosis (MAP) infections at slaughter by testing ileocaecal lymph nodes with a semi-nested IS900 PCR. Tissue samples were available within the framework of a parallel study investigating BSE-susceptibility factors in members of BSE-cohorts in the German Federal State of Lower Saxony. Ileocaecal lymph nodes were collected over a 2-year sampling period from 99 slaughter cattle of a mean age of 6.5 years (5.5-7.5 years). A recently developed IS900 semi-nested polymerase chain reaction (snPCR) assay offering a sensitivity of 1 genome equivalent was used for the detection of MAP-DNA. Based on this snPCR, 17 out of the 99 samples gave positive results, indicating a MAP occurrence of 17.17% in the random sample. All PCR products were sequenced for screening of polymorphisms. Nucleotide homologies of 98.5-100% were found with respect to the MAP K10 reference sequence IS900 (GenBank: AE16958). PCR analysis of ileocaecal lymph nodes collected from slaughter cattle proved to be a suitable technique to determine MAP occurrence in the local cattle population.     

Seasonal Patterns of Forage Availability in the Fescue Grasslands Under Contrasting Grazing Histories

Grazing by large herbivores has been shown to condition vegetation in a manner that improves grassland quality for subsequent herbivory. Fescue grasslands evolved with disturbance from fire and winter grazing by bison but are now grazed primarily by cattle during summer. We examined the effect of long-term summer grazing on the seasonal forage production and quality of fescue grasslands in an examination of the hypothesis that long-term grazing had conditioned fescue grasslands to benefit livestock. This hypothesis was examined by comparing, between grazed and ungrazed plots, the biomass and composition of herbage components, concentrations of nitrogen (N) and acid detergent fiber (ADF) therein, and the ability of major plant types to maintain their biomass and quality throughout the growing season. The study was conducted in southern Alberta at five sites that had long-term exclosures (20+ yr) on grasslands that had been moderately grazed. Grazing had no effect on the N concentration of associated grasses, but grasses had lower N concentration than forbs. Concentrations of ADF followed a reciprocal trend to N. Grazing increased the mass of forbs from about 10% to 20% as a proportion of total biomass, which in turn, was not affected by grazing history. However, this grazing-induced shift to a higher quality vegetation type was not sufficient to affect total mass of N or total digestible nutrients at the community level. Rather than changes in current growth and quality, the predominant effect of summer grazing was in reducing litter mass, which also had the potential for affecting forage production and selection by herbivores. Finally, grazing reduced the relative contribution of rough fescue to total biomass by about 30%, and despite no significant effect on the potential to support summer grazing, this change could reduce the quality of these grasslands for winter grazing.     

猪乳中一组高分子量蛋白的多态性及其与繁殖性能关系的研究

采用十二烷基硫酸钠 聚丙烯酰胺凝胶不连续垂直板电泳 (SDS PAGE)对 16 2头二花脸母猪乳中一组高分子量蛋白质 (HMWP)进行了检测 ,计算了该位点的基因型频率、等位基因频率和遗传多样性指数等 ,并运用线性模型统计方法分析了该位点的不同基因型与母猪繁殖性能的关系。结果表明 ,在二花脸猪种群 ,乳中HMWP存在B(M :11480 0± 40 0 )和D(M :10 140 0± 6 0 0 )两种带 ,分别受二个等位基因HB 和HD 控制。BB、BD和DD三种基因型频率分别为 0 6 6 6 7、0 2 716和 0 0 6 17,两个等位基因HB 和HD 频率分别为 0 80 2 5和 0 1975 ,遗传多样性指数为0 3170。在三种HMWP基因型中 ,不同基因型母猪的繁殖性能在活仔数和窝重上存在着显著差异 (P <0 0 5 ) ,但在初生仔猪个体重和 2 0日龄窝重上未达到显著水平 (P >0 0 5 )。     

Transient glomerulonephropathy associated with primary erythrocytosis in a dog

Proteinuria (urine protein/creatinine ratio, 13.6) resolved after control of primary erythrocytosis in a dog. Hydroxyurea and doxorubicin administration and phlebotomy were used initially to manage erythrocytosis. Remission was maintained for approximately 2 years. Glomerulonephropathy, characterized by absence of routine histologic or immunofluorescent changes and ultrastructural evidence of basement membrane deterioration and podocyte fusion, was documented. These lesions may have been a result of hypoxia and/or hyperviscosity secondary to erythrocytosis.     

Intracranial Lesions in Dogs With Hemangiosarcoma

A retrospective analysis of 85 dogs with hemangiosarcoma (HSA) that underwent complete necropsy, including gross examination of the brain, was conducted. Grossly identifiable intracranial lesions were present in 17 dogs. Twelve of 85 dogs (14.2%) had brain metastases. Four of 85 dogs (4.7%) had hemorrhagic lesions and/or ischemic necrosis without identifiable tumor. One dog had a primary central nervous system tumor. Signs of intracranial disease were present in six of 85 dogs (7.1%) with HSA; four had brain metastases and two had nonneoplastic lesions. Metastases had a propensity for cerebrum and gray matter. Dogs with brain metastases had more widely disseminated disease than dogs without brain metastases (P less than 0.001). Dogs with pulmonary metastases were at greater risk for developing brain metastases than dogs without pulmonary metastases (odds ratio = 8.31). Although thoracic radiography accurately identified ten of 12 dogs (83%) with pulmonary metastases, too few cases were available to assess the applicability/accuracy of thoracic radiography in predicting the presence or absence of brain metastases in dogs with malignancy and signs of intracranial disease.     

Avian influenza viruses in wild birds: a moving target

The long-standing evolutionary and ecological relationships between wild birds and influenza A viruses has created a broad pool of viral genetic diversity and a reservoir of potentially transmissible viruses. An understanding of these relationships can help us identify and modify critical control points to reduce transmission of avian influenza viruses into animal and human populations.