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OBJECTIVE: The objective of this study was to determine the seroprevalence of reproductive and infectious diseases in tropical cattle in the Tambopata and Tahuamanu Provinces in the department of Madre de Dios, Peru. SAMPLE: 156 bovines from 7 cattle farms were sampled. These farms used exclusive grazing for food and natural mating for reproduction and did not have sanitary or vaccination programs. METHODS: The serum of blood samples was subjected to ELISA with commercial kits for the detection of antibodies against Neospora caninum, Mycobacterium avium subsp paratuberculosis (MAP), Leptospira interrogans, pestivirus bovine viral diarrhea virus-1, retrovirus bovine leukemia virus (BLV), orbivirus bluetongue virus (BTV), and herpesvirus bovine herpes virus-1 (BHV). The data were analyzed by means of association tests with χ2 (P < .05) and Spearman rank correlation (P < .05) in the SPSS v.15.0 software (IBM Corp). RESULTS: A low prevalence of antibodies to L interrogans, N caninum, M avium subsp paratuberculosis, bovine viral diarrhea virus-1 was found, but it was high to BTV, BLV, and BHV (100%, 53.85%, and 72.44%, respectively). The presence of BLV and BHV was higher in the Las Piedras District, bovines less than 5 years old, and cattle with breed characteristics of zebu and crossbred (P < .01). In addition, there was a significant correlation between both infections, showing 83.3% of BLV positivity that were also BHV positive (P < .01). CLINICAL RELEVANCE: The high prevalence of antibodies to BTV, BHV, and BLV could be due to livestock management practices, direct contact with infected animals, and variation of the presence of vectors and natural reservoirs in the context of climate change in the tropics.

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BACKGROUND: Bovine herpes virus (BoHV 1 and BoHV-5) are the causative agents of infectious bovine rhinotracheitis (IBR). IBR is responsible for important economic losses in the cattle industry. The envelope glycoprotein B (gB) is essential for BoHV infection of cattle's upper respiratory and genital tract. gB is one of the main candidate antigens for a potential recombinant vaccine since it induces a strong and persistent immune response. RESULTS: In this study, gB of BoHV-1 and BoHV-5 was characterized in terms of function, structure, and antigenicity through bioinformatics tools. gB showed conserved sequence and structure, so, both domains named PH Like 1 and 2 domains of each virus were selected for the design of a bivalent vaccine candidate. The immunoinformatic study showed that these two domains have epitopes recognizable by B and T lymphocytes, followed by this, the cDNA domains from BoHV-1/5 gB (Domains-gB) were transformed into the yeast Komagataella phaffii GS115 (previously known as Pichia pastoris). A recombinant protein with molecular weight of about 110 kDa was obtained from the culture media. The vaccine candidate protein (Domains-gB) was recognized by a monoclonal antibody from a commercial ELISA kit used for IBR diagnostic, which may suggest that the epitopes are conserved of the entire infectious virus. CONCLUSION: Overall, it was shown that the recombinant domains of BoHV-1/5 gB have antigenic and immunogenic properties similar to the native gB. This vaccine candidate is promising to be used in future studies to assess its immunogenicity in an animal model.

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Background: Enzootic bovine leukosis (EBL) is a widespread infectious disease caused by the bovine leukemia virus (BLV), which results in immune system dysfunction. The resulting immunosuppression may lead to an increased prevalence of other diseases. Dairy cows infected have altered immune function associated with decreased milk production and shortened lifespan and decreased immune response to immunization. BLV infection, however, is often asymptomatic, so any connection between subclinical infection and common reproductive diseases remains unknown. This study aimed to describe the relationship between naturally occurring subclinical BLV and infectious reproductive diseases seroconversion in the field. Materials, Methods & Results: The diseases investigated included Bovine viral diarrhoea (BVD), Bovine alfaherpesvirus 1 (BoHV-1), Bovine gammaherpesvirus 4 (BoHV-4), Chlamydiosis, Leptospirosis, Brucellosis and Neosporosis in dairy cattle. Six hundred fifty-five sera samples from the northern and south-central regions of Uruguay, from asymptomatic female Holstein and Holstein crosses without a history of vaccination against reproductive diseases were processed using reference diagnostic methods (Seronautalization, ELISA, MAT, Rose Bengal Plate test). The seroprevalence of BLV was 20.0%. Seroprevalence of reproductive diseases BVD, BoHV-1 and BoHV-4 were 99.3%, 41.2% and 27.3% of the populations, respectively, and the total seroprevalence of Leptospirosis, bovine Neospora caninum and Chlamydiosis were 19.8%, 29.8% and 33.0% respectively. The results revealed positive associations between naturally contracted BLV and the presence of antibodies against BoHV-1 (P = 0.002), as well as between naturally contracted BLV and presence of antibodies against Leptospira spp. (P = 0.028). Discussion: BLV infection can impact innate and adaptive immune system cells and alter the proper functioning of uninfected cells. BLV infection may also induce changes in the complex balance of cytokine expression, cell proliferation, and programmed cell death in T- and B-lymphocytes, which is critical for immune competence and effective response to infectious challenges. The progression of BLV infection has a substantial effect on host defense mechanisms. Indeed, lowmagnitude serologic responses to a commercial foot-and-mouth disease vaccine and a J5 Escherichia coli vaccine have been observed. These results are supported by recent trial studies showing a reduced immune response to vaccination against BoHV-1 and Leptospira spp. in asymptomatic animals infected with BLV. These are 2 of the most prevalent infectious reproductive diseases in cattle worldwide, and our results provide evidence that a link between BLV and susceptibility to these diseases may exist. Although there is evidence of the co-occurrence of these diseases, it remains unknown whether there is a direct or indirect effect of BLV on infertility, embryonic loss, or abortion. Another possibility is that natural infection with these reproductive pathogens (BoHV-1, Leptospira, or others) promotes BLV expression, negatively affecting the farms where these pathogens are endemic. Considering the high seroprevalence of BLV in dairy herds in North and South America where the infection is endemic, it was explored BLV's role as an immunosuppressant by quantifying its co-occurrence with diseases that affect reproductive performance in breeding herds. Future work should clarify the role of BLV and the co-occurring pathogens in causing infertility or abortions.

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This study assessed the effects of Bisphenol A in embryonic stages of zebrafish, applying an IBR multi-biomarker approach that included alterations in growth and oxidative status and relates it with the expression of Nrf1, Nrf2, Wnt3a, Wnt8a, COX-2, Qdpra, and DKK1 genes. For this purpose, we exposed zebrafish embryos to eight environmentally relevant concentrations of BPA (220, 380, 540, 700, 860, 1180, 1340, and 1500 ng L-1) until 96 h post-fertilization. Our results show that BPA induces several malformations in embryos (developmental delay, hypopigmentation, tail malformations, and on), leading to their death. The LC50, EC50 of malformations, and teratogenic index (TI) were 1234.60 ng L-1, 987.77 ng L-1, and 1.25, respectively; thus, this emerging contaminant is teratogenic. Regarding oxidative stress and gene expression, we demonstrated BPA altered oxidative status and the gene expression in embryos of Danio rerio.

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Pooled samples are used in veterinary and human medicine as a cost-effective approach to monitor disease prevalence. Nonetheless, there is limited information on the effect of pooling on test performance, and research is required to determine the appropriate number of samples which can be pooled. Therefore, this study aimed to evaluate the use of pooled serum samples as a herd-level surveillance tool for infectious production-limiting diseases: bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR), enzootic bovine leukosis (EBL) and Neospora caninum (NC), by investigating the maximum number of samples one can pool to identify one positive animal, using commercial antibody-detection ELISAs. Four positive field standards (PFS), one for each disease, were prepared by pooling highly positive herd-level samples diagnosed using commercially available ELISA tests. These PFS were used to simulate 18 pooled samples ranging from undiluted PFS to a dilution representing 1 positive in 1,000 animals using phosphate-buffered saline as diluent. A 1:10 dilution of the PFS resulted in positive results for IBR, BVD and EBL. Moreover, for IBR and BVD, results were still positive at 1:100 and 1:30 dilutions, respectively. However, for NC, a lower dilution (8:10) was required for a seropositive result. This study indicates that, at herd-level, the use of pooled serum is a useful strategy for monitoring infectious diseases (BVD, IBR and EBL) but not NC, using readily available diagnostic assays.

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The short-term effects of coastal untreated effluents from Ushuaia Bay, Beagle Channel, on the biochemical and physiological biomarkers of Mytilus chilensis were assessed. An integrated biomarker response (IBR) index was calculated as a helpful tool to represent the general stress of the experimental organisms. Cultured mussels were exposed during 96 h to three coastal sites impacted by sewage effluents. At the beginning (T0) and every 24 h, mussels were subsampled from each site and different biochemical and physiological biomarkers were determined. There was no mortality registered in the experiments during the 96 h. However, biochemical and physiological biomarkers presented significant variations. Lipid peroxidation mean levels in mussels decreased in mantle and increased in digestive gland with respect to T0 in almost all cases. Acetylcholinesterase activity was inhibited in all sites, reaching a maximal decrease of 35% with respect to T0. Catalase remained stable and glutathione-S-transferase was activated. Oxygen consumption and ammonia excretion rates increased in organisms from two sites and, consequently, O:N ratio decreased, denoting a symptom of stress. IBR values showed the existence of different stress levels between exposed and unexposed mussels. These results exhibited an alteration of the general metabolism of mussels exposed for a short period of time to untreated coastal wastewater, suggesting the use of these organisms as early indicators of changes in the environmental quality of coastal waters of Ushuaia Bay.

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This study aimed to conduct a systematic review to estimate the economic impact of Bovine alphaherpesvirus 1 (BoAHV1) infection in Brazil using epidemiological indicators through a meta-analysis. Specific descriptors were used to retrieve studies from the Scopus, PubMed, Biblioteca Digital Brasileira de Teses e Dissertações, and Catálogo de Teses e Dissertações da Capes databases, selecting those that met the inclusion criteria established between the years 2000 and 2020. The selected studies were subjected to descriptive statistical analysis using prevalence data as the primary outcome with a 95% confidence interval (CI) with a meta-analysis of random effects and measures of heterogeneity, significance, magnitude of the effect, and measurement of publication bias. Abortion costs and estimates were calculated based on the prevalence of BoAHV1 infection in Brazil and the characteristics of the agent as viral subtypes that cause abortion, period of occurrence, average pregnancy rate, and morbidity applied to susceptible animals and animal replacement values. The results were obtained from 49 studies included for meta-analysis where a prevalence of BoAHV1 infection of 54.12% (95% CI: 49.07% - 59.26%) in the bovine population and 88.53% (95% CI: 82.97%­92.43%) was present. From the structured formula, it is estimated that 258,779 bovine abortions occur, which causes a total loss, based only on the occurrence of abortion, of US $ 48,402,244.00 to the country. It is noteworthy that because of the losses caused, strict control and eradication measures need to be implemented based on the elaboration of normative instruction that includes health education measures, vaccination, tests for traffic, and animal trade so that BoAHV1 infections do not continue to negatively impact national producers economically, productively, and socially.(AU)

Objetivou-se com o presente estudo realizar uma revisão sistemática para estimar os impactos econômicos da infecção por Alfaherpesvirus Bovino 1 no Brasil a partir dos indicadores epidemiológicos por meio de uma metanálise. Foram usados descritores específicos para a recuperação de estudos a partir das bases Scopus, Pubmed, Biblioteca Digital Brasileira de Teses e Dissertações e do Catálogo de Teses e Dissertações da Capes, selecionando-se aqueles que se enquadraram nos critérios de inclusão estabelecidos entre os anos 2000 e 2020. Os estudos selecionados foram submetidos à análise estatística descritiva utilizando-se os dados de prevalência como desfecho primário com intervalo de confiança de 95%, sendo realizado metanálise de efeito randômico e avaliadas as medidas de heterogeneidade, significância, magnitude do efeito e aferição do viés de publicação. Os custos e estimativas de aborto foram calculados com base na prevalência encontrada para BoAHV1 no Brasil e as características do agente como subtipos virais que provocam o aborto, período de ocorrência, taxa média de prenhez e morbidade aplicados aos animais suscetíveis e aos valores de reposição animal. Os resultados foram obtidos a partir de 49 estudos incluídos para metanálise, onde se verificou uma prevalência de BoAHV1 de 54,12% (IC95%: 49,07% ­ 59,26%) na população bovina e 88,53% (IC95%: 82,97% ­ 92,43%) para os rebanhos. A partir da fórmula estruturada, se estima que ocorram 258.779 abortos bovinos, que totalizam um prejuízo, apenas baseado na ocorrência do aborto, de US$ 48.402.244,00 ao país. Destaca-se que em virtude dos prejuízos ocasionados, medidas de controle e erradicação mais rigorosas precisam ser implementadas a partir da elaboração de uma instrução normativa que contemple medidas de educação sanitária, vacinação, realização de exames para o trânsito e comércio de animais para que as infecções pelo BoAHV1 não continuem a impactar negativamente os produtores nacionais de forma econômica, produtiva e socialmente.(AU)

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This study evaluated the seroprevalence and associated factors of Infectious Bovine Rhinotracheitis (IBR) and Bovine Viral Diarrhea (BVD), and to analyze the possible relationship between IBR, BVD, and the occurrence of mastitis. For this purpose, 854 crossbred dairy cows were evaluated from 69 properties allocated in the 12 municipalities that make up the Caparaó region, Espírito Santo (ES), Brazil. The seroprevalence of IBR and BVD was determined using the indirect ELISA test. Associations between variables were estimated using the prevalence ratio (PR) with a 95% confidence interval. The chi-square test was used to verify the significance of the associations (P < 0.05). The average prevalence of IBR and BVD was 48.59% and 26.46%, respectively. Animals seroreactive for IBR were more likely to develop subclinical mastitis (P < 0.01; PR: 1.27), and cows that were seroreactive for BVD were more likely to develop clinical mastitis (P < 0.01; PR: 2.24). Mechanical milking was considered a factor associated with IBR (P < 0.01; PR: 1.36) and BVD (P < 0.01; PR: 1.25). Reproductive management by natural breeding was considered a factor associated with IBR (P < 0.01; PR: 1.22). Animals seroreactive for BVD were more likely to develop reproductive problems (P < 0.01; PR: 1.34). It was concluded that the agents that cause IBR and BVD are widely disseminated in dairy cattle herds in the municipalities of the Caparaó region, ES, Brazil. The presence of IBR and BVD increased the chances of cows developing subclinical mastitis and clinical mastitis, respectively, and the cows that were mechanically milked were more likely to be seroreactive for IBR and BVD.(AU)

O objetivo do presente estudo foi avaliar a soroprevalência e os fatores de risco associados à Rinotraqueíte Infecciosa Bovina (IBR) e Diarreia Viral Bovina (BVD), e analisar a possível relação entre IBR, BVD e à ocorrência de mastite. Para tanto, foram avaliadas 854 vacas leiteiras mestiças de 69 propriedades localizadas nos 12 municípios que compõem a região do Caparaó, Espírito Santo (ES), Brasil. A soroprevalência de IBR e BVD foram determinadas pelo teste ELISA indireto. As associações entre variáveis ​​foram estimadas pela razão de prevalência (PR) com intervalo de confiança de 95%. O teste do qui-quadrado foi utilizado para verificar a significância das associações (P < 0,05). A prevalência média de IBR e BVD foi de 48% e 26%, respectivamente. Os animais sororreagentes para IBR foram mais propensos a desenvolver mastite subclínica (P < 0,01; PR: 1,27), e as vacas sororreagentes para BVD foram mais propensas a desenvolver mastite clínica (P < 0,01; PR: 2,24). À ordenha mecânica foi considerada um fator associado a IBR (P < 0,01; PR: 1,36) e BVD (P < 0,01; PR: 1,25). O manejo reprodutivo por monta natural foi considerado um fator associado IBR (P < 0,01; PR: 1,22). Os animais sororreagentes para BVD foram mais propensos a desenvolverem problemas reprodutivos (P < 0,01; PR: 1,34). Concluiu-se que os agentes causadores de IBR e BVD estão amplamente disseminados em rebanhos leiteiros nos municípios da região de Caparaó, ES, Brasil. A presença de IBR e BVD aumentaram as chances das vacas desenvolverem mastite subclínica e mastite clínica, respectivamente, e as vacas que foram ordenhadas mecanicamente apresentaram maior probabilidade de serem sororreagente para IBR e BVD.(AU)

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This study evaluated the seroprevalence and associated factors of Infectious Bovine Rhinotracheitis (IBR) and Bovine Viral Diarrhea (BVD), and to analyze the possible relationship between IBR, BVD, and the occurrence of mastitis. For this purpose, 854 crossbred dairy cows were evaluated from 69 properties allocated in the 12 municipalities that make up the Caparaó region, Espírito Santo (ES), Brazil. The seroprevalence of IBR and BVD was determined using the indirect ELISA test. Associations between variables were estimated using the prevalence ratio (PR) with a 95% confidence interval. The chi-square test was used to verify the significance of the associations (P < 0.05). The average prevalence of IBR and BVD was 48.59% and 26.46%, respectively. Animals seroreactive for IBR were more likely to develop subclinical mastitis (P < 0.01; PR: 1.27), and cows that were seroreactive for BVD were more likely to develop clinical mastitis (P < 0.01; PR: 2.24). Mechanical milking was considered a factor associated with IBR (P < 0.01; PR: 1.36) and BVD (P < 0.01; PR: 1.25). Reproductive management by natural breeding was considered a factor associated with IBR (P < 0.01; PR: 1.22). Animals seroreactive for BVD were more likely to develop reproductive problems (P < 0.01; PR: 1.34). It was concluded that the agents that cause IBR and BVD are widely disseminated in dairy cattle herds in the municipalities of the Caparaó region, ES, Brazil. The presence of IBR and BVD increased the chances of cows developing subclinical mastitis and clinical mastitis, respectively, and the cows that were mechanically milked were more likely to be seroreactive for IBR and BVD.

O objetivo do presente estudo foi avaliar a soroprevalência e os fatores de risco associados à Rinotraqueíte Infecciosa Bovina (IBR) e Diarreia Viral Bovina (BVD), e analisar a possível relação entre IBR, BVD e à ocorrência de mastite. Para tanto, foram avaliadas 854 vacas leiteiras mestiças de 69 propriedades localizadas nos 12 municípios que compõem a região do Caparaó, Espírito Santo (ES), Brasil. A soroprevalência de IBR e BVD foram determinadas pelo teste ELISA indireto. As associações entre variáveis ​​foram estimadas pela razão de prevalência (PR) com intervalo de confiança de 95%. O teste do qui-quadrado foi utilizado para verificar a significância das associações (P < 0,05). A prevalência média de IBR e BVD foi de 48% e 26%, respectivamente. Os animais sororreagentes para IBR foram mais propensos a desenvolver mastite subclínica (P < 0,01; PR: 1,27), e as vacas sororreagentes para BVD foram mais propensas a desenvolver mastite clínica (P < 0,01; PR: 2,24). À ordenha mecânica foi considerada um fator associado a IBR (P < 0,01; PR: 1,36) e BVD (P < 0,01; PR: 1,25). O manejo reprodutivo por monta natural foi considerado um fator associado IBR (P < 0,01; PR: 1,22). Os animais sororreagentes para BVD foram mais propensos a desenvolverem problemas reprodutivos (P < 0,01; PR: 1,34). Concluiu-se que os agentes causadores de IBR e BVD estão amplamente disseminados em rebanhos leiteiros nos municípios da região de Caparaó, ES, Brasil. A presença de IBR e BVD aumentaram as chances das vacas desenvolverem mastite subclínica e mastite clínica, respectivamente, e as vacas que foram ordenhadas mecanicamente apresentaram maior probabilidade de serem sororreagente para IBR e BVD.

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ABSTRACT: This study evaluated the seroprevalence and associated factors of Infectious Bovine Rhinotracheitis (IBR) and Bovine Viral Diarrhea (BVD), and to analyze the possible relationship between IBR, BVD, and the occurrence of mastitis. For this purpose, 854 crossbred dairy cows were evaluated from 69 properties allocated in the 12 municipalities that make up the Caparaó region, Espírito Santo (ES), Brazil. The seroprevalence of IBR and BVD was determined using the indirect ELISA test. Associations between variables were estimated using the prevalence ratio (PR) with a 95% confidence interval. The chi-square test was used to verify the significance of the associations (P < 0.05). The average prevalence of IBR and BVD was 48.59% and 26.46%, respectively. Animals seroreactive for IBR were more likely to develop subclinical mastitis (P < 0.01; PR: 1.27), and cows that were seroreactive for BVD were more likely to develop clinical mastitis (P < 0.01; PR: 2.24). Mechanical milking was considered a factor associated with IBR (P < 0.01; PR: 1.36) and BVD (P < 0.01; PR: 1.25). Reproductive management by natural breeding was considered a factor associated with IBR (P < 0.01; PR: 1.22). Animals seroreactive for BVD were more likely to develop reproductive problems (P < 0.01; PR: 1.34). It was concluded that the agents that cause IBR and BVD are widely disseminated in dairy cattle herds in the municipalities of the Caparaó region, ES, Brazil. The presence of IBR and BVD increased the chances of cows developing subclinical mastitis and clinical mastitis, respectively, and the cows that were mechanically milked were more likely to be seroreactive for IBR and BVD.

RESUMO: O objetivo do presente estudo foi avaliar a soroprevalência e os fatores de risco associados à Rinotraqueíte Infecciosa Bovina (IBR) e Diarreia Viral Bovina (BVD), e analisar a possível relação entre IBR, BVD e à ocorrência de mastite. Para tanto, foram avaliadas 854 vacas leiteiras mestiças de 69 propriedades localizadas nos 12 municípios que compõem a região do Caparaó, Espírito Santo (ES), Brasil. A soroprevalência de IBR e BVD foram determinadas pelo teste ELISA indireto. As associações entre variáveis ​​foram estimadas pela razão de prevalência (PR) com intervalo de confiança de 95%. O teste do qui-quadrado foi utilizado para verificar a significância das associações (P < 0,05). A prevalência média de IBR e BVD foi de 48% e 26%, respectivamente. Os animais sororreagentes para IBR foram mais propensos a desenvolver mastite subclínica (P < 0,01; PR: 1,27), e as vacas sororreagentes para BVD foram mais propensas a desenvolver mastite clínica (P < 0,01; PR: 2,24). À ordenha mecânica foi considerada um fator associado a IBR (P < 0,01; PR: 1,36) e BVD (P < 0,01; PR: 1,25). O manejo reprodutivo por monta natural foi considerado um fator associado IBR (P < 0,01; PR: 1,22). Os animais sororreagentes para BVD foram mais propensos a desenvolverem problemas reprodutivos (P < 0,01; PR: 1,34). Concluiu-se que os agentes causadores de IBR e BVD estão amplamente disseminados em rebanhos leiteiros nos municípios da região de Caparaó, ES, Brasil. A presença de IBR e BVD aumentaram as chances das vacas desenvolverem mastite subclínica e mastite clínica, respectivamente, e as vacas que foram ordenhadas mecanicamente apresentaram maior probabilidade de serem sororreagente para IBR e BVD.

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Com frequência, infecções virais são associadas a problemas da reprodução em rebanhos de bovinos de corte e leite de todo o mundo. Este estudo teve como objetivo avaliar variáveis de manejo que possam constituir fatores de risco da infecção por BoHV-1 e/ou por BVDV em rebanhos leiteiros com histórico de problemas da reprodução em vacas mestiças em manejo extensivo e sem histórico de vacinação prévia para o controle de IBR e BVD. Anticorpos neutralizantes anti-BoHV-1, anti-BVDV e para ambos os vírus simultaneamente foram identificados em 62,5% (165/264), 45,1% (119/264) e 31,4% (83/264), respectivamente, das amostras analisadas. Os fatores de risco associados à infecção por BoHV-1 foram rebanhos com número total de fêmeas superior a 100, presença de ordenha mecânica, não utilização de inseminação artificial na reprodução e a compra infrequente de animais. Para BVDV, os fatores de risco foram aptidão mista (leite/corte) do rebanho, presença de ordenha mecânica, ausência de quarentena para os animais recém-adquiridos, presença de piquete de parição e a não utilização de inseminação artificial. Para a infecção simultânea (BoHV-1/BVDV), a presença de ordenha mecânica aumentou o risco em 3,36 vezes, e o uso de inseminação artificial reduziu em 56% o risco de infecção nos rebanhos avaliados.(AU)

Viral infections are frequently associated with reproductive problems in dairy and beef cattle worldwide. The aim of this study was to verify managerial practices that may constitute risk factors associated with infection by BoHV-1 and/or BVDV in dairy herds with a history of reproductive disease in extensively reared dairy cows without a previous history of vaccination against IBR and BVD. Neutralizing antibodies anti-BoHV-1, anti-BVDV or both were detected in 62.5% (165/264), 45.1% (119/264), and 31.4% (83/264), respectively, in the samples analyzed. The risk factors associated with infection by BoHV-1 were herds with more than 100 cows, the presence of mechanical milking, the non-utilization of artificial insemination, and the infrequent acquisition of animals. Risk factors associated with BVDV were dual-purpose herds (milk and beef), these include the utilization of mechanical milking, absence of quarantine for newly acquired animals, the presence of picket calving, and the absence of artificial insemination. For simultaneous infections by both viruses (BoHV-1 and BVDV) the use of mechanical milking increased the chance of infection 3.36-fold while the use of artificial insemination reduced the risk of infection by 56% in these herds.(AU)

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Com frequência, infecções virais são associadas a problemas da reprodução em rebanhos de bovinos de corte e leite de todo o mundo. Este estudo teve como objetivo avaliar variáveis de manejo que possam constituir fatores de risco da infecção por BoHV-1 e/ou por BVDV em rebanhos leiteiros com histórico de problemas da reprodução em vacas mestiças em manejo extensivo e sem histórico de vacinação prévia para o controle de IBR e BVD. Anticorpos neutralizantes anti-BoHV-1, anti-BVDV e para ambos os vírus simultaneamente foram identificados em 62,5% (165/264), 45,1% (119/264) e 31,4% (83/264), respectivamente, das amostras analisadas. Os fatores de risco associados à infecção por BoHV-1 foram rebanhos com número total de fêmeas superior a 100, presença de ordenha mecânica, não utilização de inseminação artificial na reprodução e a compra infrequente de animais. Para BVDV, os fatores de risco foram aptidão mista (leite/corte) do rebanho, presença de ordenha mecânica, ausência de quarentena para os animais recém-adquiridos, presença de piquete de parição e a não utilização de inseminação artificial. Para a infecção simultânea (BoHV-1/BVDV), a presença de ordenha mecânica aumentou o risco em 3,36 vezes, e o uso de inseminação artificial reduziu em 56% o risco de infecção nos rebanhos avaliados.(AU)

Viral infections are frequently associated with reproductive problems in dairy and beef cattle worldwide. The aim of this study was to verify managerial practices that may constitute risk factors associated with infection by BoHV-1 and/or BVDV in dairy herds with a history of reproductive disease in extensively reared dairy cows without a previous history of vaccination against IBR and BVD. Neutralizing antibodies anti-BoHV-1, anti-BVDV or both were detected in 62.5% (165/264), 45.1% (119/264), and 31.4% (83/264), respectively, in the samples analyzed. The risk factors associated with infection by BoHV-1 were herds with more than 100 cows, the presence of mechanical milking, the non-utilization of artificial insemination, and the infrequent acquisition of animals. Risk factors associated with BVDV were dual-purpose herds (milk and beef), these include the utilization of mechanical milking, absence of quarantine for newly acquired animals, the presence of picket calving, and the absence of artificial insemination. For simultaneous infections by both viruses (BoHV-1 and BVDV) the use of mechanical milking increased the chance of infection 3.36-fold while the use of artificial insemination reduced the risk of infection by 56% in these herds.(AU)

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Zinc is an essential trace mineral that is involved in many biological processes. In elevated concentrations, this metal may have toxic effects for aquatic organisms. Physicochemical properties of water, such as salinity and hardness, can influence the bioavailability of zinc and, therefore its toxicity in aquatic environments. Therefore, this study aimed investigate the influence of salinity, hardness on Zn toxicity on the behaviours and biochemical parameters of the estuarine guppy (Poecilia vivipara). The fish were exposed to waterborne zinc (500 µg L-1) in salt water (25 ppt) or hard water (120 mg L-1 CaCO3). For behavioural analysis, the locomotive and exploratory parameters of fish in novel environment and light-dark tests were evaluated. We observed that exposure to hard water decreased the distance covered by the fish, and when zinc also present the vertical exploratory behavior decreased. When zinc was tested alone, an increase in the maximum speed of fish was recorded. Activities of antioxidant enzymes, levels of lipid peroxidation, protein carbonylation, total peroxidation and, reactive oxygen species content, antioxidant capacity against peroxyl radicals, non-proteins thiols levels, acetylcholinesterase and Na+/K+-ATPase activities were evaluated in the whole fish body. The integrated biomarker response was calculated for each parameter to aid in the interpretation of the results and indicated that hard water containing zinc had the greatest effect on the biochemical parameters of the fish. In general, neither salinity nor hardness were totally effective in protecting the guppy from the biochemical damage caused by exposure to zinc.

Assuntos

RESUMO

Among reproductive disorders in dairy and beef cattle worldwide, embryonic mortalities stand out as one of the most frequent. Because of the multifactorial etiology, the clinical and laboratory diagnoses of embryonic mortality causes in cattle are quite complex. Often, infectious causes may account for up to 50% of bovine embryonic mortality rates after 30 days of conception. This review will address the main causes of early and late embryonic mortality, with emphasis on infectious causes and, particularly, those more frequent in the Brazilian cattle herds. In addition, we will discuss ways of controlling and prophylaxis including those related to reproductive and sanitary management, with emphasis on immunoprophylaxis of the three most frequent reproductive infectious diseases in Brazilian dairy and beef cattle herds.

RESUMO

Among reproductive disorders in dairy and beef cattle worldwide, embryonic mortalities stand out as one of the most frequent. Because of the multifactorial etiology, the clinical and laboratory diagnoses of embryonic mortality causes in cattle are quite complex. Often, infectious causes may account for up to 50% of bovine embryonic mortality rates after 30 days of conception. This review will address the main causes of early and late embryonic mortality, with emphasis on infectious causes and, particularly, those more frequent in the Brazilian cattle herds. In addition, we will discuss ways of controlling and prophylaxis including those related to reproductive and sanitary management, with emphasis on immunoprophylaxis of the three most frequent reproductive infectious diseases in Brazilian dairy and beef cattle herds.(AU)

Assuntos

RESUMO

Among reproductive disorders in dairy and beef cattle worldwide, embryonic mortalities stand out as one of the most frequent. Because of the multifactorial etiology, the clinical and laboratory diagnoses of embryonic mortality causes in cattle are quite complex. Often, infectious causes may account for up to 50% of bovine embryonic mortality rates after 30 days of conception. This review will address the main causes of early and late embryonic mortality, with emphasis on infectious causes and, particularly, those more frequent in the Brazilian cattle herds. In addition, we will discuss ways of controlling and prophylaxis including those related to reproductive and sanitary management, with emphasis on immunoprophylaxis of the three most frequent reproductive infectious diseases in Brazilian dairy and beef cattle herds.

Assuntos

RESUMO

Bovine herpesvirus 1 (BoHV-1) is an important bovine pathogen that is responsible for causing respiratory diseases and reproductive failures. The presence of BoHV-1 in an in vitro embryo production system affects fertilization, maturation, and embryonic development. The objective of this study was to evaluate the developmental capacity of oocytes from naturally infected cows with no reproductive history. Moreover, this study investigated the presence of viral DNA in cumulus oophorus complexes (COCs). Experimental groups were differentiated by titrating the antibodies detected through seroneutralization assays, establishing three groups: seronegative animals (titer lower than 2), low titer (2 to 8), and animals with a titer above or equal to 16. COCs were obtained from 15 donors during 22 sessions of ultrasound-guided follicular aspiration. DNA was extracted from a pool of COCs obtained from all aspirations from the same donor as well as from whole blood and nested PCR reactions were performed. Only COCs with a compact layer of cumulus cells, an intact zona pellucida, and homogeneous cytoplasm were selected for in vitro culture and evaluation of nuclear maturation rate. After culturing for 24 hours, the oocytes were fixed and stained to evaluate the meiotic cell cycle stage. Oocytes that showed a chromosomal configuration in metaphase II were considered to have reached nuclear maturation. Compared with the other groups, the oocyte nuclear maturation rate in animals with a titer greater than or equal to 16 (50%) was compromised (P<0.05). However, the viral titer did not influence the maturation rate of bovine oocytes in animals exhibiting low titration (62.2%) when compared with the control group (76.7%). Viral DNA was not observed in the blood samples but was detected in the COC pool from three seropositive donors. In view of the results obtained, we conclude that natural infections by the BoHV-1 virus can compromise the nuclear maturation rate in cows, depending on the titration levels of antibodies against the virus. Moreover, viral DNA could be present in COCs, contradicting the hypothesis that seropositive animals with no history of clinical symptomatology pose a negligible risk of transmitting BoHV-1 by COCs.(AU)

Herpesvírus bovino 1 (BoHV-1) é um importante patógeno bovino, responsável por causar doenças respiratórias e falhas reprodutivas. A presença do BoHV-1 em sistema de produção in vitro de embriões afeta a fertilização, a maturação e o desenvolvimento embrionário. O objetivo deste estudo foi avaliar a capacidade de desenvolvimento de ovócitos oriundos de vacas infectadas naturalmente sem histórico reprodutivo. Além disso, este estudo investigou a presença do DNA viral em Complexos Cumulus Ooforus (COCs). Os tratamentos foram definidos a partir do título de anticorpos detectados pelos ensaios de soroneutralização, sendo estabelecidos três grupos: animais soronegativos (título menor do que 2), título baixo (2 a 8) e animais com título maior ou igual a 16. Os COCs foram obtidos de 15 doadoras durante 22 sessões de aspiração folicular guiada por ultrassom. A extração do DNA foi realizada em um pool de COCs de todas as aspirações de uma mesma doadora e no sangue total para a realização das reações de Nested-PCR. Para avaliação da taxa de maturação nuclear, foram selecionados para o cultivo in vitro somente os COCs com camada compacta de células do cumulus, zona pelúcida íntegra e citoplasma homogêneo. Após 24 horas de cultivo, os ovócitos foram fixados e corados em lâmina para a avaliação do estádio do ciclo celular meiótico. Os ovócitos que apresentaram configuração cromossômica em metáfase II foram considerados como tendo alcançado a maturação nuclear. Verificou-se comprometimento na taxa de maturação nuclear ovocitária (P<0.05) nos animais de título maior ou igual a 16 (50%). No entanto, não houve influência do título viral na taxa de maturação de ovócitos bovinos em animais que apresentaram titulação baixa (62,2%) quando comparados com o grupo controle (76,7%). O DNA viral não foi identificado nas amostras de sangue, mas foi detectado no pool de COCs de três doadoras soropositivas. Diante dos resultados encontrados conclui-se que vacas infectadas naturalmente pelo vírus BoHV-1 apresentam comprometimento na taxa de maturação nuclear, dependendo do grau de titulação de anticorpos contra o vírus. Ademais, o DNA viral pode estar presente em COCs contrariando a hipótese de que animais sorologicamente positivos e sem histórico de sintomatologia clínica oferecem risco negligível de transmissão do BoHV-1 por COCs.(AU)

Assuntos

RESUMO

Bovine herpesvirus 1 (BoHV-1) is an important bovine pathogen that is responsible for causing respiratory diseases and reproductive failures. The presence of BoHV-1 in an in vitro embryo production system affects fertilization, maturation, and embryonic development. The objective of this study was to evaluate the developmental capacity of oocytes from naturally infected cows with no reproductive history. Moreover, this study investigated the presence of viral DNA in cumulus oophorus complexes (COCs). Experimental groups were differentiated by titrating the antibodies detected through seroneutralization assays, establishing three groups: seronegative animals (titer lower than 2), low titer (2 to 8), and animals with a titer above or equal to 16. COCs were obtained from 15 donors during 22 sessions of ultrasound-guided follicular aspiration. DNA was extracted from a pool of COCs obtained from all aspirations from the same donor as well as from whole blood and nested PCR reactions were performed. Only COCs with a compact layer of cumulus cells, an intact zona pellucida, and homogeneous cytoplasm were selected for in vitro culture and evaluation of nuclear maturation rate. After culturing for 24 hours, the oocytes were fixed and stained to evaluate the meiotic cell cycle stage. Oocytes that showed a chromosomal configuration in metaphase II were considered to have reached nuclear maturation. Compared with the other groups, the oocyte nuclear maturation rate in animals with a titer greater than or equal to 16 (50%) was compromised (P<0.05). However, the viral titer did not influence the maturation rate of bovine oocytes in animals exhibiting low titration (62.2%) when compared with the control group (76.7%). Viral DNA was not observed in the blood samples but was detected in the COC pool from three seropositive donors. In view of the results obtained, we conclude that natural infections by the BoHV-1 virus can compromise the nuclear maturation rate in cows, depending on the titration levels of antibodies against the virus. Moreover, viral DNA could be present in COCs, contradicting the hypothesis that seropositive animals with no history of clinical symptomatology pose a negligible risk of transmitting BoHV-1 by COCs.(AU)

Herpesvírus bovino 1 (BoHV-1) é um importante patógeno bovino, responsável por causar doenças respiratórias e falhas reprodutivas. A presença do BoHV-1 em sistema de produção in vitro de embriões afeta a fertilização, a maturação e o desenvolvimento embrionário. O objetivo deste estudo foi avaliar a capacidade de desenvolvimento de ovócitos oriundos de vacas infectadas naturalmente sem histórico reprodutivo. Além disso, este estudo investigou a presença do DNA viral em Complexos Cumulus Ooforus (COCs). Os tratamentos foram definidos a partir do título de anticorpos detectados pelos ensaios de soroneutralização, sendo estabelecidos três grupos: animais soronegativos (título menor do que 2), título baixo (2 a 8) e animais com título maior ou igual a 16. Os COCs foram obtidos de 15 doadoras durante 22 sessões de aspiração folicular guiada por ultrassom. A extração do DNA foi realizada em um pool de COCs de todas as aspirações de uma mesma doadora e no sangue total para a realização das reações de Nested-PCR. Para avaliação da taxa de maturação nuclear, foram selecionados para o cultivo in vitro somente os COCs com camada compacta de células do cumulus, zona pelúcida íntegra e citoplasma homogêneo. Após 24 horas de cultivo, os ovócitos foram fixados e corados em lâmina para a avaliação do estádio do ciclo celular meiótico. Os ovócitos que apresentaram configuração cromossômica em metáfase II foram considerados como tendo alcançado a maturação nuclear. Verificou-se comprometimento na taxa de maturação nuclear ovocitária (P<0.05) nos animais de título maior ou igual a 16 (50%). No entanto, não houve influência do título viral na taxa de maturação de ovócitos bovinos em animais que apresentaram titulação baixa (62,2%) quando comparados com o grupo controle (76,7%). O DNA viral não foi identificado nas amostras de sangue, mas foi detectado no pool de COCs de três doadoras soropositivas. Diante dos resultados encontrados conclui-se que vacas infectadas naturalmente pelo vírus BoHV-1 apresentam comprometimento na taxa de maturação nuclear, dependendo do grau de titulação de anticorpos contra o vírus. Ademais, o DNA viral pode estar presente em COCs contrariando a hipótese de que animais sorologicamente positivos e sem histórico de sintomatologia clínica oferecem risco negligível de transmissão do BoHV-1 por COCs.(AU)

Assuntos

RESUMO

Infecções que ocasionam mortalidade embrionária e fetal são responsáveis por mais de 50% dosproblemas reprodutivos em bovinos de todo o mundo. Várias classes de micro-organismos, destacando-se entreelas bactérias, vírus e protozoários podem infectar o trato reprodutivo trazendo consequências deletérias à fêmeabovina e, principalmente ao concepto (embrião ou feto). A rinotraqueíte infecciosa bovina, a diarreia viralbovina e a leptospirose são as três principais doenças infecciosas que comprometem a reprodução em bovinos decorte e leite de todas as regiões geográficas brasileiras. Essa revisão abordará aspectos relativos à importância dasanidade no contexto da produção animal; formas de ocorrência das infecções reprodutivas; etiologias;características clínicas e epidemiológicas das três principais infecções, métodos de diagnóstico etiológico esorológico, finalizando com descrição formas de controle e profilaxia com destaque para os programas devacinação.

Infections that cause embryonic and fetal mortality are responsible for over than 50% of reproductivefailure in cattle worldwide. Several classes of microorganisms, including bacteria, viruses, and protozoa caninfect the reproductive tract bringing deleterious consequences to the cow, and particularly to the concept(embryo or fetus). The infectious bovine rhinotracheitis, bovine viral diarrhea, and leptospirosis are three majorinfectious diseases that compromise reproduction in dairy and beef cattle herds of all Brazilian geographicalregions. This review will address aspects relating to the importance of health in the context of animalproduction; forms of occurrence of reproductive infections; etiologies; clinical and epidemiologicalcharacteristics of the three main infections, methods of etiological and serological diagnosis, ending withdescription of control and prophylaxis forms with emphasis on vaccination programs.

Assuntos

RESUMO

Infecções que ocasionam mortalidade embrionária e fetal são responsáveis por mais de 50% dosproblemas reprodutivos em bovinos de todo o mundo. Várias classes de micro-organismos, destacando-se entreelas bactérias, vírus e protozoários podem infectar o trato reprodutivo trazendo consequências deletérias à fêmeabovina e, principalmente ao concepto (embrião ou feto). A rinotraqueíte infecciosa bovina, a diarreia viralbovina e a leptospirose são as três principais doenças infecciosas que comprometem a reprodução em bovinos decorte e leite de todas as regiões geográficas brasileiras. Essa revisão abordará aspectos relativos à importância dasanidade no contexto da produção animal; formas de ocorrência das infecções reprodutivas; etiologias;características clínicas e epidemiológicas das três principais infecções, métodos de diagnóstico etiológico esorológico, finalizando com descrição formas de controle e profilaxia com destaque para os programas devacinação.(AU)

Infections that cause embryonic and fetal mortality are responsible for over than 50% of reproductivefailure in cattle worldwide. Several classes of microorganisms, including bacteria, viruses, and protozoa caninfect the reproductive tract bringing deleterious consequences to the cow, and particularly to the concept(embryo or fetus). The infectious bovine rhinotracheitis, bovine viral diarrhea, and leptospirosis are three majorinfectious diseases that compromise reproduction in dairy and beef cattle herds of all Brazilian geographicalregions. This review will address aspects relating to the importance of health in the context of animalproduction; forms of occurrence of reproductive infections; etiologies; clinical and epidemiologicalcharacteristics of the three main infections, methods of etiological and serological diagnosis, ending withdescription of control and prophylaxis forms with emphasis on vaccination programs.(AU)

Assuntos