Development and standardization of an indirect ELISA for the serological diagnosis of classical swine fever

An indirect enzyme linked immunoassay (ELISA-I) was developed and standardized for the serological diagnosis of classical swine fever (CSF). For the comparison, nine hundred and thirty-seven swine serum samples were tested by serum neutralization followed by immunoperoxidase staining (NPLA), considered as the standard. Of these, 223 were positive and 714 negative for neutralizing antibodies to classical swine fever virus (CSFV). In relation to the NPLA, the ELISA-I presented a 98.2% sensitivity; 92.86% specificity, 81.11% positive predictive value, 99.4% negative predictive value and a 94.1% precision. Statistical analysis showed a very strong correlation (r=0,94) between both tests. When compared to a commercially available ELISA kit, the performance of both, in relation to the NPLA, was similar. It was concluded that the ELISA-I is suitable for large scale screening of antibodies to classical swine fever virus, although it does not distinguish antibodies to classical swine fever virus from those induced by other pestiviruses.

Animal infections by vaccinia-like viruses in the state of Rio de Janeiro: an expanding disease

In the present study we investigated the presence of infections by vaccinia-like viruses in dairy cattle from 12 counties in the state of Rio de Janeiro in the last 9 years. Clinical specimens were collected from adult animals with vesicular/pustular lesions mainly in the udder and teats, and from calves with lesions around the nose and mouth. A plaque reduction neutralization test (PRNT) was applied to search for antibodies to Orthopoxvirus; the vesicular/pustular fluids and scabs were examined by PCR, electron microscopy (EM) and by inoculation in VERO cells for virus isolation. Antibodies to Orthopoxvirus were detected in most cases. The PCR test indicated a high nucleotide homology among the isolates and the vaccinia viruses (VACV) used as controls. By EM, typical orthopoxvirus particles were observed in some specimens. The agents isolated in tissue culture were confirmed as vaccinia-like viruses by EM and PCR. The HA gene of the vaccinia-like Cantagalo/IOC virus isolated in our laboratory was sequenced and compared with other vaccinia-like isolates, showing high homology with the original Cantagalo strain, both strains isolated in 1999 from dairy cattle. Antibodies to Orthopoxvirus were detected in one wild rodent (genus Akodon sp.) collected in the northwestern region of the state, indicating the circulation of poxvirus in this area. Nonetheless, PCR applied to tissue samples collected from the wild rodents were negative. Vesicular/pustular lesions in people in close contact with animals have been also recorded. Thus, the vaccinia-like virus infections in cattle and humans in the state seem to be an expanding condition, resulting in economic losses to dairy herds and leading to transient incapacitating human disease. Therefore, a possible immunization of the dairy cattle in the state should be carefully evaluated.

Spatialization of climate, physical and socioeconomic factors that affect the dairy goat production in Brazil and their impact on animal breeding decisions

Brazil has high climate, soil and environmental diversity, as well as distinct socioeconomic and political realities, what results in differences among the political administrative regions of the country. The objective of this study was to determine spatial distribution of the physical, climatic and socioeconomic aspects that best characterize the production of dairy goats in Brazil. Production indices of milk per goat, goat production, milk production, as well as temperature range, mean temperature, precipitation, normalized difference vegetation index, relative humidity, altitude, agricultural farms; farms with native pasture, farms with good quality pasture, farms with water resources, farms that receive technical guidance, family farming properties, non-familiar farms and the human development index were evaluated. The multivariate analyses were carried out to spatialize climatic, physical and socioeconomic variables and so differenciate the Brazilian States and Regions. The highest yields of milk and goat production were observed in the Northeast. The Southeast Region had the second highest production of milk, followed by the South, Midwest and North. Multivariate analysis revealed distinctions between clusters of political-administrative regions of Brazil. The climatic variables were most important to discriminate between regions of Brazil. Therefore, it is necessary to implement animal breeding programs to meet the needs of each region.

Doenças de ovinos diagnosticadas no Laboratório de Anatomia Patológica Animal da Universidade Federal de Mato Grosso do Sul (1996-2010)

Nas últimas décadas a pecuária ovina cresceu significativamente no Brasil. Concomitantemente, grupos de pesquisas e laboratórios de diagnósticos realizam estudos retrospectivos com a finalidade de fornecer subsídios técnico-científicos para os médicos veterinários. Desta forma, realizou-se um estudo de prevalência nos arquivos do Laboratório de Anatomia Patológica Animal (LAP) da Universidade Federal de Mato Grosso do Sul (UFMS) no período de Janeiro de 1996 a Dezembro de 2010. O Laboratório de Bacteriologia da UFMS e o Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul forneceram apoio diagnóstico nos casos de mannheimiose pulmonar e scrapie, respectivamente. Os laudos da espécie ovina foram revisados e agrupados em conclusivos e inconclusivos, dos quais foram excluídos os casos experimentais e de outros estados e países. Os casos conclusivos foram classificados de acordo com a etiologia da doença. Os exames da espécie ovina somaram 331 laudos (3,97 %) de um total de 8.333 casos diagnosticados no período. Destes, foram excluídos sessenta e quatro (19,3%) casos experimentais e materiais oriundos de outros estados ou países. Dos 267 casos remanescentes, 87 (32,6%) foram inconclusivos e 180 (67,4%) considerados conclusivos, sendo 60 (33,3%) doenças infecciosas e parasitárias; 45 (25%) intoxicações e toxi-infecções; 41 (22,8%) "lesões sem causa definida"; 22 (12,2%) doenças metabólicas e nutricionais; 10 (5,6%) foram classificadas como "outros distúrbios" e 2 (1,1%) neoplasmas. A hemoncose, intoxicação por Brachiaria spp., pleuropneumonias, broncopneumonias, pneumonias fibrinonecrosante ou fibrinossupurativa sem causa definida e a intoxicação por cobre foram as doenças mais prevalentes no período estudado. Dois casos de scrapie foram diagnosticados no período.

Técnicas anatômicas no ensino da prática de anatomia animal

A preocupação quanto a conservação de peças anatômicas existe a mais de 5 mil anos, pois o uso de peças cadavéricas são indispensáveis para o ensino, contribuindo com a melhora das habilidades aplicativas, assimilativas e compreensivas da disciplina. Esse trabalho propõe maior utilização das técnicas apresentadas em laboratórios de anatomia, visando abolir o uso do formol como conservante, permitindo um ambiente agradável para a prática da relação ensino-aprendizagem. Para isso foram utilizadas quatro técnicas anatômicas, a criodesidratação, glicerinação, injeção de látex e injeção de vinilite seguido de corrosão, que foram executadas utilizando cães, gatos e órgãos provenientes de doações. Com a criodesidratação e glicerinação os materiais anatômicos ficaram consideravelmente mais leves do que eram quando mantidos em formol, mantendo-se inodoros, diferente do evidenciado na utilização de formol e outros conservantes. As estruturas de estudo das peças ficaram intactas, de fácil visualização e o armazenamento passou a ser feito em caixas fechadas sem qualquer tipo de liquido, mantendo-se assim por até 3 anos. As técnicas de injeção de látex e vinilite seguido de corrosão mostraram total eficiência preenchendo os sistemas injetados, podendo visualizar as ramificações e todo caminho percorrido no sistema circulatório. As quatro técnicas anatômicas estudadas nesse trabalho mostraram ser suficientes para atender as necessidades dos estudantes quanto ao estudo da anatomia, devido à perfeita evidenciação de estruturas externas e internas dos animais.

Emerging animal viruses: real threats or simple bystanders?

The list of animal viruses has been frequently added of new members raising permanent concerns to virologists and veterinarians. The pathogenic potential and association with disease have been clearly demonstrated for some, but not for all of these emerging viruses. This review describes recent discoveries of animal viruses and their potential relevance for veterinary practice. Dogs were considered refractory to influenza viruses until 2004, when an influenza A virus subtype H3N8 was transmitted from horses and produced severe respiratory disease in racing greyhounds in Florida/USA. The novel virus, named canine influenza virus (CIV), is considered now a separate virus lineage and has spread among urban canine population in the USA. A new pestivirus (Flaviviridae), tentatively called HoBi-like pestivirus, was identified in 2004 in commercial fetal bovine serum from Brazil. Hobi-like viruses are genetically and antigenically related to bovine viral diarrhea virus (BVDV) and induce similar clinical manifestations. These novel viruses seem to be widespread in Brazilian herds and have also been detected in Southeast Asia and Europe. In 2011, a novel mosquito-borne orthobunyavirus, named Schmallenberg virus (SBV), was associated with fever, drop in milk production, abortion and newborn malformation in cattle and sheep in Germany. Subsequently, the virus disseminated over several European countries and currently represents a real treat for animal health. The origin of SBV is still a matter of debate but it may be a reassortant from previous known bunyaviruses Shamonda and Satuperi. Hepatitis E virus (HEV, family Hepeviridae) is a long known agent of human acute hepatitis and in 1997 was first identified in pigs. Current data indicates that swine HEV is spread worldwide, mainly associated with subclinical infection. Two of the four HEV genotypes are zoonotic and may be transmitted between swine and human by contaminated water and undercooked pork meat. The current distribution and impact of HEV infection in swine production are largely unknown. Avian gyrovirus type 2 (AGV2) is a newly described Gyrovirus, family Circoviridae, which was unexpectedly found in sera of poultry suspected to be infected with chicken anemia virus (CAV). AGV2 is closely related to CAV but displays sufficient genomic differences to be classified as a distinct species. AGV2 seems to be distributed in Brazil and also in other countries but its pathogenic role for chickens is still under investigation. Finally, the long time and intensive search for animal relatives of human hepatitis C virus (HCV) has led to the identification of novel hepaciviruses in dogs (canine hepacivirus [CHV]), horses (non-primate hepaciviruses [NPHV] or Theiler's disease associated virus [TDAV]) and rodents. For these, a clear and definitive association with disease is still lacking and only time and investigation will tell whether they are real disease agents or simple spectators.

QT interval in healthy dogs: which method of correcting the QT interval in dogs is appropriate for use in small animal clinics?

The electrocardiography (ECG) QT interval is influenced by fluctuations in heart rate (HR) what may lead to misinterpretation of its length. Considering that alterations in QT interval length reflect abnormalities of the ventricular repolarisation which predispose to occurrence of arrhythmias, this variable must be properly evaluated. The aim of this work is to determine which method of correcting the QT interval is the most appropriate for dogs regarding different ranges of normal HR (different breeds). Healthy adult dogs (n=130; German Shepherd, Boxer, Pit Bull Terrier, and Poodle) were submitted to ECG examination and QT intervals were determined in triplicates from the bipolar limb II lead and corrected for the effects of HR through the application of three published formulae involving quadratic, cubic or linear regression. The mean corrected QT values (QTc) obtained using the diverse formulae were significantly different (ρ<0.05), while those derived according to the equation QTcV = QT + 0.087(1- RR) were the most consistent (linear regression). QTcV values were strongly correlated (r=0.83) with the QT interval and showed a coefficient of variation of 8.37% and a 95% confidence interval of 0.22-0.23 s. Owing to its simplicity and reliability, the QTcV was considered the most appropriate to be used for the correction of QT interval in dogs.

Cardiothoracic ratio and vertebral heart size (VHS) to standardize the heart size of the tufted capuchin (Cebus apella Linnaeus, 1758) in computerized radiographic images

Abstract: The VHS and CTR were assessed using computerized thoracic radiographs of ten clinically healthy tufted capuchin monkeys (five males and five females) from the Wild Animal Screening Center in São Luís (Centro de Triagem de Animais Silvestres de São Luís-MA-CETAS). Radiographs were taken in laterolateral and dorsoventral projections to calculate the cardiothoracic ratio (VHS) and vertebral heart size (CTR). The VHS showed mean values of 9.34±0.32v (males) and 9.16±0.34v (females) and there was no statistical difference between males and females (p>0.05). The CTR showed mean values of 0.55±0.04 (males) and 0.52±0.03 (females) and there was no statistical difference between the sexes (p>0.05). There was positive correlation between VHS and CTR (r=0.78). The thoracic and heart diameters showed mean values of 5.70±0.48cm and 2.16±0.40cm in the males, respectively. In the females they measured 5.32±0.39cm and 2.94±0.32cm. There was no statistical difference between the sexes. Our results show that the high correlation found between VHS and CTR permitted the verification with similar clinical precision between the two methods to estimate alterations in the heart silhouette by radiographic examination of tufted capuchin, making it an easy technique to apply that can be considered in the investigation of heart problems for this wild species.

Improving farm animal welfare

Kirjallisuusarvostelu

Reflectance indices as a diagnostic tool for weed control performed by multipurpose equipment in precision agriculture

Several tools of precision agriculture have been developed for specific uses. However, this specificity may hinder the implementation of precision agriculture due to an increasing in costs and operational complexity. The use of vegetation index sensors which are traditionally developed for crop fertilization, for site-specific weed management can provide multiple utilizations of these sensors and result in the optimization of precision agriculture. The aim of this study was to evaluate the relationship between reflectance indices of weeds obtained by the GreenSeekerTM sensor and conventional parameters used for weed interference quantification. Two experiments were conducted with soybean and corn by establishing a gradient of weed interference through the use of pre- and post-emergence herbicides. The weed quantification was evaluated by the normalized difference vegetation index (NDVI) and the ratio of red to near infrared (Red/NIR) obtained using the GreenSeekerTM sensor, the visual weed control, the weed dry matter, and digital photographs, which supplied information about the leaf area coverage proportions of weed and straw. The weed leaf coverage obtained using digital photography was highly associated with the NDVI (r = 0.78) and the Red/NIR (r = -0.74). The weed dry matter also positively correlated with the NDVI obtained in 1 m linear (r = 0.66). The results indicated that the GreenSeekerTM sensor originally used for crop fertilization could also be used to obtain reflectance indices in the area between rows of crops to support decision-making programs for weed control.

Weed mapping using techniques of precision agriculture

The aim of this study was to identify and map the weed population in a no-tillage area. Geostatistical techniques were used in the mapping in order to assess this information as a tool for the localized application of herbicides. The area of study is 58.08 hectares wide and was sampled in a fixed square grid (which point spaced 50 m, 232 points) using a GPS receiver. In each point the weeds species and population were analyzed in a square with a 0.25 m2 fixed area. The species Ipomoea grandifolia, Gnaphalium spicatum, Richardia spp. and Emilia sonchifolia have presented no spatial dependence. However, the species Conyza spp., C. echinatus and E. indica have shown a spatial correlation. Among the models tested, the spherical model has shown had a better fit for Conyza spp. and Eleusine indica and the Gaussian model for Cenchrus echinatus. The three species have a clumped spatial distribution. The mapping of weeds can be a tool for localized control, making herbicide use more rational, effective and economical.

Reprodução sexuada de Dyckia tuberosa (Vell.) Beer (Bromeliaceae, Pitcairnioideae) e interação planta-animal

Bromeliaceae é um componente importante em vários Biomas, sendo notável a variedade de contextos ecológicos em que pode ser encontrada. Ocorre no grupo a combinação entre dois modos de reprodução: sexuada e propagação clonal. Neste estudo descrevemos vários atributos relacionados à reprodução sexuada de Dyckia tuberosa, bem como interações planta-animal que se estabelecem em suas estruturas reprodutivas. Ao longo de 11 meses, 55 % dos indivíduos na população estudada floresceram e frutificaram. As flores se desenvolvem da base para o ápice e apresentam diferenças morfométricas quanto à posição na inflorescência que acarretam diferenças na produção de sementes. A concentração de açúcares no néctar foi de 20% e a produção total de néctar foi de c. de 24 µL flor-1 dia-1, sendo esta última maior no período da manhã entre 8h00 e 9h00. Dyckia tuberosa é auto-incompatível e o índice de auto-incompatibilidade (ISI) foi de 0,08. Somente beija-flores exploraram as flores de modo legítimo, contatando anteras e estigma, sendo 3,9 flores visitadas por hora. Chlorostilbon aureoventris, Colibri serrirostris e Phaethornis eurynome foram as espécies registradas. Em D. tuberosa a reprodução sexuada depende das visitas dos beijaflores. Houve patrulhamento das inflorescências de D. tuberosa pelas formigas Camponotus rufipes, Camponotus cf. mus e Cephalotes sp. Como há ausência de reprodução sexuada em muitos indivíduos, e esta espécie é dominante no afloramento rochoso estudado, consideramos que a propagação clonal seja uma estratégia importante para a disseminação de D. tuberosa na área. A presença de animais, polinizadores ou não, na inflorescência de D. tuberosa torna esta espécie adequada para avaliar como variações na disponibilidade de recursos florais alteram o resultado das interações planta-animal e o sucesso reprodutivo de D. tuberosa.

Production of recombinant antigens in plants for animal and human immunization - a review

Plants present a cost effective production system for high value proteins. There is an increasing world demand for cheap vaccines that can be readily administered to the population, especially in economically less developed regions. A promising concept is the production of vaccines in plants that could be grown locally. Expression of antigenic peptides in the palatable parts of plants can lead to the production of edible active vaccines. Two major strategies are: i) to express antigens in transgenic plants, and ii) to produce antigenic peptides on the surface of plant viruses that could be used to infect host plants. This review considers the experimental data and early results for both strategies, and discusses the potential and problems of this new technology

Animal models of anxiety: an ethological perspective

In the field of anxiety research, animal models are used as screening tools in the search for compounds with therapeutic potential and as simulations for research on mechanisms underlying emotional behaviour. However, a solely pharmacological approach to the validation of such tests has resulted in distinct problems with their applicability to systems other than those involving the benzodiazepine/GABAA receptor complex. In this context, recent developments in our understanding of mammalian defensive behaviour have not only prompted the development of new models but also attempts to refine existing ones. The present review focuses on the application of ethological techniques to one of the most widely used animal models of anxiety, the elevated plus-maze paradigm. This fresh approach to an established test has revealed a hitherto unrecognized multidimensionality to plus-maze behaviour and, as it yields comprehensive behavioural profiles, has many advantages over conventional methodology. This assertion is supported by reference to recent work on the effects of diverse manipulations including psychosocial stress, benzodiazepines, GABA receptor ligands, neurosteroids, 5-HT1A receptor ligands, and panicolytic/panicogenic agents. On the basis of this review, it is suggested that other models of anxiety may well benefit from greater attention to behavioural detail