Improvement of thermal comfort indices in agroforestry systems in the southern Brazilian Amazon.

Agroforestry systems can minimize heat stress and improve cattle welfare, but the influence of the forest component in microclimatic changes in the southern Amazon remains unclear. This study aimed to compare the thermal comfort indices in grass monoculture and integrated systems. The three systems were pasture under full sunlight (PFS), integrated (triple-row) livestock-forestry (ILFT), and integrated (single-row) livestock-forestry (ILFs), across four seasons, for two years, from June 2017 to June 2019. We assessed photosynthetically active radiation (PAR), air temperature, relative humidity, black globe temperature, and wind speed. Thermal comfort indices such as temperature-humidity index (THI), black globe temperature-humidity index (BGHI), and radiant thermal load (RTL) were calculated based on microclimate data daily-collected from 8:00 to 16:00. The ILFT mean THI (76.8) was slightly lower than ILFS and PFS. The BGHI and RTL values decreased as shading increased (PFS > ILFs > ILFT). The most challenging heat stress conditions for grazing animals occurred predominately during winter and autumn. In conclusion, the presence of trees in pastures of the southern Amazon improved the microclimate and, consequently, the thermal comfort indices. Agroforestry systems can foster an environment with a more suitable thermal comfort or less restrictive to animal performance, which contribute to mitigating global climate change for forage-livestock systems in Brazilian Amazon.

Comparison of McMaster and Mini-FLOTAC fecal egg counting techniques in cattle and horses.

The aim of this study was to compare two fecal egg count (FEC) techniques; McMaster (McM) and Mini-FLOTAC (mF), for the detection of cattle and horse gastrointestinal nematode eggs, in different locations. Experiment 1: feces were collected from 16 cattle and FEC was performed individually, using mF with the sensitivity of 5 eggs per gram of feces (EPG) and McM with a sensitivity of 50 EPG at Empresa de Pesquisa Agropecuária de Minas Gerais - EPAMIG and the Laboratory of Parasitic Diseases of the University of Parana - LDP/UFPR. Experiment 2: Fecal samples from 30 horses were analyzed with mF (sensitivity of 5 EPG) and McM (sensitivity of 25 EPG) at the University of Mato Grosso do Sul - UFMS and LPD/UFPR. Experiment 3: feces were collected from 14 foals and FEC was performed using mF (sensitivity of 5 EPG); and McM (sensitivity of 25 EPG) only at the LPD/UFPR. For cattle, the average FEC of mF was 962 at LPD; and 1248 at EPAMIG; for McM it was 1393 at LPD and 1563 at EPAMIG. For horses, the FEC average using the mF was 650 at LPD and 469 at UFMS; and for McM it was 677 at LPD and 554 at UFMS. For foals, the average FEC for mF was 404 and 436 for McM. In all experiments, the standard deviation and the coefficient of variation values were significantly lower for mF. Therefore, it is recommended the use of the Mini-FLOTAC technique, which is a method with less variability and higher accuracy, particularly for animals with low FEC.

Parameter estimation and use of gamma interferon assay for the diagnosis of bovine tuberculosis in Brazil / Estimação dos parâmetros e uso do teste do interferon gama para o diagnóstico da tuberculose bovina no Brasil

This study aimed to evaluate the interference of tuberculin test on the gamma-interferon (INFg) assay, to estimate the sensitivity and specificity of the INFg assay in Brazilian conditions, and to simulate multiple testing using the comparative tuberculin test and the INFg assay. Three hundred-fifty cattle from two TB-free and two TB-infected herds were submitted to the comparative tuberculin test and the INFg assay. The comparative tuberculin test was performed using avian and bovine PPD. The INFg assay was performed by the BovigamTM kit (CSL Veterinary, Australia), according to the manufacturer's specifications. Sensitivity and specificity of the INFg assay were assessed by a Bayesian latent class model. These diagnostic parameters were also estimate for multiple testing. The results of INFg assay on D0 and D3 after the comparative tuberculin test were compared by the McNemar's test and kappa statistics. Results of mean optical density from INFg assay on both days were similar. Sensitivity and specificity of the INFg assay showed results varying (95% confidence intervals) from 72 to 100% and 74 to 100% respectively. Sensitivity of parallel testing was over 97.5%, while specificity of serial testing was over 99.7%. The INFg assay proved to be a very useful diagnostic method.(AU)

O presente estudo avalia a interferência do teste de tuberculinização no teste do interferon gama (INFg), estima a sensibilidade e a especificidade do INFg em condições brasileiras e simula a utilização dos testes múltiplos usando a tuberculinização comparada e o teste do INFg. Trezentos e cinquenta animais oriundos de dois rebanhos livres e dois rebanhos positivos foram submetidos à tuberculinização comparada e ao teste de INFg. A tuberculinização comparada foi realizada utilizando PPD aviária e bovina. O teste de INFg foi realizado utilizando o kit Bovigam® (CSL Veterinary, Austrália) de acordo com as especificações do fabricante. A sensibilidade e especificidade do teste de INFg foram calculadas pelo Modelo Bayesiano de Classe Latente. Esses parâmetros foram também estimados para os testes múltiplos. Os resultados do teste de INFg no D0 e D3 após o teste de tuberculinização foram comparados pelos testes estatísticos de McNemar e kappa. Os resultados das médias de densidade ótica do teste de INFg em ambos os dias foram similares. A sensibilidade e a especificidade do teste de INFg apresentaram resultados variando (95% intervalo de confiança) de 72 a 100% e 74 a 100%, respectivamente. A sensibilidade do teste em paralelo foi acima de 97,5% enquanto a especificidade do teste em série foi acima de 99,7%. O teste do INFg provou ser um método de diagnóstico muito útil.(AU)

Comparação entre a imunidade induzida em bovinos vacinados com bacterinas polivalentes comerciais e uma monovalente experimental / Comparison between immunity induced in cattle vaccinated with commercial polyvalent bacterins and one experimental monovalent

O presente estudo avaliou a indução da produção de anticorpos contra Leptospira spp.por dez bacterinas, sendo nove polivalentes e uma monovalente experimental para a sorovariedade Hardjo amostra Norma. A concentração celular foi controlada e utilizou-se adjuvante de emulsão óleo em água. Um ensaio imunoenzimático (ELISA) indireto foi desenvolvido utilizando-se conjugado anti-IgG total para mensurar os níveis de anticorpos da classe IgG conferido pelas bacterinas utilizando três amostras diferentes: Hardjoprajitino, Norma e Hardjo-bovis. Paralelamente foi utilizado também o Teste de Soroaglutinação Microscópica (SAM) para mensurar os níveis de anticorpos contra as mesmas amostras. Encontraram-se títulos variáveis entre as bacterinas de acordo com o teste ELISA. Os títulos no SAM foram de pouca intensidade e de curta duração indicando a necessidade de controle celular para uma posterior padronização destes produtos. Com base nos resultados encontrados no presente estudo, a bacterina monovalente foi a que apresentou melhor desempenho.

The study evaluated the induction of antibody production against ten bacterins, nine polyvalent and one experimental monovalent to serovar Hardjo strain Norma. An indirect enzyme linked immunosorbent assay (ELISA) was developed using anti-IgG conjugate to measure total levels of IgG class antibodies conferred by bacterins using three different strains: Hardjoprajiitino, Norma and Hardjo-bovis. Microscopic Agglutination Test (MAT) was also used to measure immunoglobulin levels of the same strains. Variable ELISA titers were induced by the tested bacterins. The MAT titers found showed lower intensity and shorter duration, indicating the need to cellular control in further standardization of these vaccines. Based on results of this study, the monovalent bacterin showed best performance.