Influence of silvopastoral systems on gastrointestinal nematode infection and immune response of Nellore heifers under tropical conditions.

Among the strategies for integrating crops, livestock, and forestry, silvopastoral systems must be highlighted due to their inherent microclimatic conditions, mainly in tropical countries such as Brazil, where cattle are frequently subjected to unfavorable thermal conditions. However, according to some studies, shading can potentially worsen herds´ parasitism due to better microclimatic condition for the parasites. This study aimed to assess fecal egg count in Nellore heifers reared in two silvopastoral arrangements (pasture with single or triple tree rows), in a crop-livestock system, and open pasture. In the silvopastoral treatment composed of triple rows, lesser parasite burden means were found, with a peak infection in February/March and another in October. Regarding the effect of seasons over the year, there was an environmental influence on the egg counts, with higher averages during the late rainy season and the beginning of the dry season. An immunological investigation of animals from each group showed that cattle kept on the silvopastoral arrangements with either single or triple rows have significantly higher lymphocyte proliferation when stimulated with specific antigens than those kept on open pastures. Based on our results, it can be concluded that both silvopastoral systems were not considered as a risk factor for nematode egg counts in Nellore heifers. Indeed, the shadiest system promoted milder parasitism and higher immunological lymphocyte responses in animals.

Serological and molecular detection of Theileria equi in horses from Sinop, Mato Grosso state, Brazil / Detecção sorológica e molecular de Theileria equi em equinos oriundos de Sinop, Mato Grosso, Brasil

Equine piroplasmosis is the most important tick-borne disease to affect horses in Brazil. Theileria equi is one of the causative agents of equine piroplasmosis. Chronic cases are expected, in which the animals show no apparent signs of infection and remain asymptomatic but constitute a source of the infectious agent that ticks can spread. This study was conducted across 81 ranches located in the municipality of Sinop, State of Mato Grosso, Brazil. A sample calculation was performed to estimate the apparent prevalence of T. equi among horses. A total of 1,853 animals were included in the sampling analysis based on the information available from the Institute of Agricultural and Livestock Defense of Mato Grosso State. The serological analysis of 367 serum samples using an indirect enzyme-linked immunosorbent assay (ELISA) to detect anti-T. equi antibodies revealed that 337 animals were positive, representing a frequency of 90.70%. The molecular analysis to amplify the EMA-1 gene showed positivity in 20 of 89 tested samples. The fragments of four samples were sequenced and analyzed to determine their similarities to sequences from other species, based on sequences deposited at GenBank. All showed 100% similarity with T. equi. Our study represents the first report of T. equi antibodies among the equids in north-central region of Mato Grosso, revealing the widespread distribution of seropositive animals.

A piroplasmose equina é a doença transmitida por carrapatos mais importante em cavalos no Brasil. Theileria equi é um dos agentes causadores da piroplasmose equina. São esperados casos crônicos, nos quais os animais não apresentam sinais aparentes de infecção e permanecem assintomáticos, mas constituem uma fonte de infecção e disseminação por carrapatos. Este estudo foi realizado em 81 fazendas localizadas no município de Sinop, Estado de Mato Grosso, Brasil. Um cálculo amostral foi realizado para estimar a prevalência aparente de T. equi entre cavalos. No total, 1.853 animais foram incluídos na análise amostral com base nas informações disponíveis no Instituto de Defesa Agropecuária do Estado de Mato Grosso. A análise sorológica de 367 amostras de soro por meio de ensaio imunoenzimático indireto (ELISA) para detecção de anticorpos anti-T. equi revelou que 337 animais eram positivos, representando uma frequência de 90,70%. A análise molecular para o gene EMA-1 mostrou positividade em 20 das 89 amostras testadas. Os fragmentos de quatro amostras foram sequenciados e analisados para determinar suas semelhanças com sequências de outras espécies, a partir das sequências depositadas no GenBank. Todos mostraram 100% de similaridade com T. equi. Nosso estudo representa o primeiro relato de anticorpos contra T. equi entre os equídeos na região centro norte de Mato Grosso, revelando a ampla distribuição de animais soropositivos.

Serological and molecular detection of Theileria equi in horses from Sinop, Mato Grosso state, Brazil / Detecção sorológica e molecular de Theileria equi em equinos oriundos de Sinop, Mato Grosso, Brasil

Equine piroplasmosis is the most important tick-borne disease to affect horses in Brazil. Theileria equi is one of the causative agents of equine piroplasmosis. Chronic cases are expected, in which the animals show no apparent signs of infection and remain asymptomatic but constitute a source of the infectious agent that ticks can spread. This study was conducted across 81 ranches located in the municipality of Sinop, State of Mato Grosso, Brazil. A sample calculation was performed to estimate the apparent prevalence of T. equi among horses. A total of 1,853 animals were included in the sampling analysis based on the information available from the Institute of Agricultural and Livestock Defense of Mato Grosso State. The serological analysis of 367 serum samples using an indirect enzyme-linked immunosorbent assay (ELISA) to detect anti-T. equi antibodies revealed that 337 animals were positive, representing a frequency of 90.70%. The molecular analysis to amplify the EMA-1 gene showed positivity in 20 of 89 tested samples. The fragments of four samples were sequenced and analyzed to determine their similarities to sequences from other species, based on sequences deposited at GenBank. All showed 100% similarity with T. equi. Our study represents the first report of T. equi antibodies among the equids in north-central region of Mato Grosso, revealing the widespread distribution of seropositive animals.

A piroplasmose equina é a doença transmitida por carrapatos mais importante em cavalos no Brasil. Theileria equi é um dos agentes causadores da piroplasmose equina. São esperados casos crônicos, nos quais os animais não apresentam sinais aparentes de infecção e permanecem assintomáticos, mas constituem uma fonte de infecção e disseminação por carrapatos. Este estudo foi realizado em 81 fazendas localizadas no município de Sinop, Estado de Mato Grosso, Brasil. Um cálculo amostral foi realizado para estimar a prevalência aparente de T. equi entre cavalos. No total, 1.853 animais foram incluídos na análise amostral com base nas informações disponíveis no Instituto de Defesa Agropecuária do Estado de Mato Grosso. A análise sorológica de 367 amostras de soro por meio de ensaio imunoenzimático indireto (ELISA) para detecção de anticorpos anti-T. equi revelou que 337 animais eram positivos, representando uma frequência de 90,70%. A análise molecular para o gene EMA-1 mostrou positividade em 20 das 89 amostras testadas. Os fragmentos de quatro amostras foram sequenciados e analisados para determinar suas semelhanças com sequências de outras espécies, a partir das sequências depositadas no GenBank. Todos mostraram 100% de similaridade com T. equi. Nosso estudo representa o primeiro relato de anticorpos contra T. equi entre os equídeos na região centro norte de Mato Grosso, revelando a ampla distribuição de animais soropositivos.

Epidemiological investigation of Borrelia burgdorferi in horses in the municipality of Sinop-MT, Brazil.

Borrelia burgdorferi sensu stricto is the main etiological agent of Lyme disease (LD) in the USA. In Brazil, it is believed that a similar spirochete is the causal agent of the Baggio-Yoshinari syndrome (BYS), a zoonosis also transmitted by ticks, whose clinical manifestations are similar to those of LD. Despite the epidemiological importance, there are no studies reporting the presence and the prevalence of B. burgdorferi among horses in Mato Grosso State. The aim of this study was to detect and measure the frequency of IgG antibodies anti-B. burgdorferi American strain G39/40 in horses in the municipality of Sinop, MT-Brazil, using the indirect enzyme-linked immunosorbent assay (ELISA) for serological diagnosis. Blood samples from 367 horses were collected in 81 farms. An epidemiological questionnaire was applied during the visits to obtain information related to the animals and the farms. From the 367 horses, 214 were positive for B. burgdorferi sensu stricto according to the results of the ELISA test, representing an apparent prevalence of 54.04% [CI = 0.4548051-0.6237234]. Concomitantly, 89 blood samples were taken for molecular analysis by nested polymerase chain reaction (PCR). According to the PCR test results, none of the samples were reactive, although 53 of these samples were reactive according to ELISA. Seventy five farms (92.59%) had at least one reactive horse for B. burgdorferi. Our results support the hypothesis of the presence of anti-Borrelia spp. antibodies in horses in Mato Grosso, reaching a high animal prevalence. Besides that, leisure/sport purposes proved to be a risk factor, with an odds ratio of 3.16. These findings clearly indicate the need of borreliosis control in Sinop and make a significant contribution to the knowledge of the disease in Mato Grosso.

Characterization of the sheep industry in the medium northern region of Mato Grosso, Brazil

Nas últimas décadas o mercado brasileiro de carne ovina aumentou substancialmente, e o estado de Mato Grosso apresentou a maior taxa de crescimento do Brasil, apesar da falta de informações sobre os sistemas de produção nesta região. Este estudo teve como objetivo caracterizar os sistemas de produção de ovinos da região meio-norte do Mato Grosso, utilizando um questionário com perguntas qualitativas e quantitativas. Dentre as 40 propriedades avaliadas foram predominantes (82,5%; 33/40) rebanhos com menos de 100 animais, com exploração semi-intensiva, voltada para a produção de carne. A ovinocultura foi citada como atividade econômica secundária em 92,5% (37/40) dos rebanhos e, em 60,0% (24/40) das propriedades, os animais eram mantidos apenas para consumo familiar. O manejo sanitário deficiente resultou na ocorrência de diversas doenças, sendo os casos de miíases os mais citados (65,0%; 26/40). A ovinocultura possui grande potencial para o desenvolvimento em Mato Grosso. No entanto, a atividade ainda é negligenciada em muitos aspectos, incluindo a saúde animal.

In recent decades, the Brazilian market for sheep meat has increased substantially, and the State of Mato Grosso had the highest growth rate in Brazil. However, information about ovine production systems in this region is lacking. This study aimed to characterize productive systems of sheep in the medium northern region of Mato Grosso, by application of qualitative and quantitative questionnaires. Among 40 properties evaluated, herds there were predominately with fewer than 100 animals (82.5%, 33/40), with semi-intensive exploration focused on meat production. Livestock sheep was a secondary economic activity in 92.5% (37/40) of farms, and sheep were kept only for family consumption in 60.0% (24/40). Poor health management resulted in the occurrence of various diseases, and myiasis was the most frequently cited disease (65.0%, 26/40). Sheep farming has a great potential for development in Mato Grosso. However, the activity is neglected in many ways, including animal health.

Prevalence and risk factors associated with anti-Neospora caninum antibodies in dairy herds in the central region of Minas Gerais State, Brazil.

Neospora caninum is one of the parasites that frequently causes reproductive loses in cattle herds all over the world. Surveys have shown a high prevalence of the parasite in herds; in certain locations, 90% to 100% of dairy holdings are positives according serological tests. The aim of this study was to estimate the prevalence and risk factors associated with the increased number of seropositive dairy cattle in the central region of Minas Gerais, the largest milk producer state in Brazil. Samples were collected from 151 dairy herds and from 2915 lactating cows, and were evaluated by an indirect ELISA assay. According to results, animal prevalence was 21.9% (CI 95%: 18.9 to 24.9%), while the herd prevalence it was 98.5% (CI 95%: 97.0 to 99.9%). Poisson regression estimate the herd risk factors associated with the increased number of cases. An increased number of positive animals was related to the previous history of abortion and the presence of dogs. The use of individual natural colostrum feeding and reproductive techniques such as embryo transfer and in vitro fertilization are associated with a reduced number of seropositive animals in the herd. In conclusion, Neospora caninum is overspread across the dairy herds of the region, and it may be causing major economic losses for dairy farmers. The use of reproduction techniques, the access of dogs to the herds and the management of calf colostrum are important issues to be considered in the control of the disease.

Improved grazing activity of dairy heifers in shaded tropical grasslands / Novilhas leiteiras melhoram sua atividade de pastejo em pastagens tropicais sombreadas

ABSTRACT: Trees in the production systems can effectively reduce hot weather-induced stress in the Brazilian Midwest. High temperatures cause changes in animals daily routine, and trees into pastures can promote benefits. The aim of this research was to evaluate the behavior of dairy heifers in silvopastoral systems in the state of Mato Grosso, Brazil. A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein/Zebu), 350kg average weight, was evaluated over three seasons. Piatã grass was managed under three shade levels: full-sun, moderate-shade, and intensive-shade provided by 10 to 12m high Eucalyptus trees. Behavior data were collected every 15 minutes from 8:30h to 16h. Shade availability significantly impacted heifer behavior, mainly affecting grazing frequency and time during the hottest hours. Grazing behavior was affected by shade levels during the different seasons. Heifers showed preferred grazing times. Heifers in the intensive-shade system visited shady areas during the hottest hours throughout the seasons. Heifers in the full sun-system avoided grazing during the warmer times, ceasing feeding activities. Our results from the Brazilian Midwest showed that shade availability causes breed heifers to change their daily routine.

RESUMO: A presença de árvores em sistemas de produção animal pode reduzir o estresse provocado pelo calor no centro-oeste brasileiro. As altas temperaturas induzem a uma mudança na rotina dos animais e, as árvores dentro da pastagem podem promover benefícios. O objetivo desta pesquisa foi avaliar o comportamento de novilhas leiteiras em sistemas integrados no Mato Grosso, Brasil. Um grupo de 24 novilhas cruzadas (3/4 e 5/8 Holandês: Gir) de 350kg foi avaliado em três estações do ano. O capim piatã foi manejado sob três níveis de sombreamento: pleno sol e sombreamentos moderado e intenso promovidos por eucaliptos com 12m de altura. O comportamento das novilhas foi medido a cada 15 minutos entre 8h30min às 16h. A disponibilidade de sombra modificou o padrão de comportamento das novilhas, afetando a frequência e o tempo de pastejo nas horas mais quentes do dia. O comportamento de pastejo foi afetado pelos níveis de sombra e, variou nas diferentes estações do ano. As novilhas em sistemas com sombreamento intenso procuraram pela sombra nas horas mais quentes do dia durante as três estações do ano avaliadas. Já, as novilhas nas condições de pastagem a pleno sol, não pastejaram durante as horas mais quentes do dia, pois interrompiam suas atividades e permaneciam inativas durante grande período do dia. A disponibilidade de sombra induz novilhas cruzadas a mudarem sua rotina diária nas condições do Centro-Oeste brasileiro.

The influence of trees on the thermal environment and behaviour of grazing heifers in Brazilian Midwest.

The intensification of the livestock production system has gained prominence over the last decades. In addition to the reduction of grazing areas and increased productivity per hectare, the intercropping involving forest tree species and ruminants has been established as a sustainable production model, generating income and valuation of natural capital. Besides the social, economic, and environmental aspects, the animal welfare is a noteworthy factor. The objective of this study was to evaluate the microclimatic conditions in an open-pasture and in silvopastoral systems, considering the Temperature Humidity Index (THI) and alterations in animal behavior. Three different pasture arrangements were analyzed in this study: total absence of trees in an open-pasture (ArrA), presence of peripheral trees (Eucalyptus spp.) along the border fences (ArrB), and an intensive wooded area aggregated with pasture (ArrC). A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein-Girolando breed) was evaluated. Behavior data were collected every 15 min starting at 08 h00 with readings ending at 16 h00. THI was used to evaluate the environmental comfort. The THI found in the system with open-pasture and in the two systems with silvopastoral arrangement reached critical levels. The two arrangements with eucalyptus rows were not capable of eliminating heat stress in the conditions found in the north region of Mato Grosso State although better conditions were obtained under the tree canopy. The differences between the microclimatic variables for the three arrangements modified the behavior of the animals regarding their location and activity, except for water consumption.

Prevalence and risk factors for bovine tuberculosis in Minas Gerais State, Brazil.

The aim of the present study was to estimate the prevalence and regional spread of bovine tuberculosis in the state of Minas Gerais, Brazil, to identify herd-level risk factors, and to provide guidance for disease control and mitigation of its impact in public health. The study comprised a large-scale random sample survey of 22,990 animals and 1586 herds, distributed in seven regions. A questionnaire was applied on each farm to collect epidemiological and herd management data. Overall, 5.04 % of herds and 0.81 % of animals were positive for bovine tuberculosis. The highest herd prevalence was found in Alto Paranaíba, an expanding dairy region. The more technologically advanced dairy herds showed a prevalence ratio of 2.83 compared to others and are obvious candidates for risk-based surveillance and herd accreditation schemes. Small farms cannot be left out of disease control efforts because they are the vast majority of herds, albeit with lower individual risk. With regard to public health, there is widespread practice of producing homemade fresh cheese with raw milk and of slaughtering culled cows in places without sanitary inspection. This poses a risk to consumers and limits the efficacy of surveillance at slaughter.

Estimating the abortion risk difference in Neospora caninum seropositive dairy cattle in Brazil / Estimativa da diferença do risco de aborto em vacas leiteiras soropositivas para Neospora caninum no Brasil

Neosporosis in cattle herds is associated with large economic losses, with abortion being the only clinical sign perceptible to the producer. Losses are estimated at over one billion dollars worldwide. This study aimed to estimate the abortion risk difference in seropositive animals using specific data for dairy herds in Brazil. Differences in the risk of abortion between seropositive and seronegative animals were calculated through a meta-analysis of previous data from several Brazilian states, and an increase of 10.04% (0.091 to 0.118) in the specific risk was identified. This finding indicates that more than 474,000 abortions caused by neosporosis may be occurring only in dairy cattle herds in Brazil, causing a major economic loss in the milk production chain. The use of this specific measure for Brazilian herds opens the possibility of developing cost-benefit analysis for neosporosis in Brazil using data that are more reliable

A neosporose está relacionada a grandes perdas econômicas em rebanhos bovinos, tendo o abortamento como único sinal clínico perceptível ao produtor, com prejuízos estimados em mais de um bilhão de dólares em todo o mundo. O presente trabalho teve como objetivo estimar a diferença no risco de aborto em animais soropositivos, especificamente com dados procedentes de rebanhos leiteiros do Brasil. A diferença do risco de aborto foi calculada através de uma meta-análise, com dados precedentes de vários estados brasileiros, tendo como resultado um aumento de 10,04% (0,091-0,118) no risco específico. Este resultado demonstra que podem estar ocorrendo mais de 474 mil abortamentos no Brasil, devido à neosporose, apenas em rebanhos bovinos leiteiros, causando grandes perdas econômicas para cadeia produtora de leite. A utilização dessa medida específica de rebanhos brasileiros abre a possibilidade de modelagem econômica do custo da doença no Brasil com dados mais fidedignos