Monitoring bovine tick fever on a dairy farm: An economic proposal for rational use of medications.

In this study, we evaluated the monitoring of tick fever (TF) in a Brazilian dairy farm in the Minas Gerais state, Brazil, from July 10 to August 4, 2018. We aimed to identify diagnostic and treatment flaws in the protocol adopted by the farm, and to establish a novel and accurate TF monitoring protocol based on precision dairy farming and rational use of antimicrobials and antiparasitic drugs, while evaluating the economic benefits of the proposed strategy. We monitored TF in 395 heifer calves aged between 3 and 14 mo. According to the farm's standard protocol, all calves with an increase of 0.5°C in rectal temperature compared with the previous week's measurement were treated for Anaplasma spp. and Babesia spp. Blood smears were collected from the tail tip of the treated calves. During the last week of the study, we prepared blood smears of all calves regardless of treatment indication. Economic analysis was performed. The results indicated that at least 56.86% (261/459) of the calves did not require treatment for TF, whereas only 23.09% (106/459) had treatment indications. Negative blood smears (45.97%; 211/459) indicated the possibility of calves being affected by another disease or a condition that was not being adequately treated or those not necessarily sick. These results demonstrate the excessive use of medications, representing a direct economic loss, in addition to potentially favoring the occurrence of resistance to antimicrobials. In contrast, 9.42% (26/276) of calves had no treatment indication based on rectal temperature but had treatment indications based on blood smears. Only 5.73% (42/735) of blood smears had co-infection with hemopathogens, and none had triple co-infection. Therefore, we proposed the monitoring of TF using rectal temperature and microscopic analysis. If implemented, this strategy would result in a direct annual savings of approximately $22,638.96 (77.99%) related to medication for the treatment of TF. Therefore, implementing the proposed protocol would be cheaper than treatment based only on rectal temperatures. The currently implemented TF protocols overestimate the occurrence of TF, resulting in overtreatment. Thus, implementing a TF monitoring protocol based on a microscopy tool is justified, with benefits including rational use of medication, potential to generate savings, and reduced morbidity and mortality rates, in addition to enabling other diagnoses.

An outbreak of compressive myelopathy due to pyogranulomatous reaction to the oily adjuvant of the foot-and-mouth disease vaccine - case report / Surto de mielopatia compressiva associada à reação piogranulomatosa ao adjuvante oleoso da vacina contra Febre Aftosa em Minas Gerais - relato de caso

Cases of compressive myelopathy syndrome associated with post vaccinal pyogranulomas were diagnosed post mortem in three cows from a farm in Minas Gerais state, Brazil. These cows presented ataxia and bilateral paresis of the pelvic limbs, which evolved to paralysis, and sternal recumbence. On necropsy, locally extensive areas of the longissimus dorsi muscle were replaced by pyogranulomas supported by moderate amounts of fibrous connective tissue. On the cut surface, some nodules contained yellowish and viscous fluid (purulent exudate) or whitish fluid (interpreted as the oily adjuvant of a vaccine). In the spinal canal of the subjacent vertebrae, compressing the spinal cord, were pyogranulomas identical to those described in the skeletal muscle. Histologically, the pyogranulomas were composed of a central clear vacuole (consistent with the space left by the oil adjuvant droplets), surrounded by neutrophils and, more externally, by large numbers of epithelioid macrophages and fewer multinucleated giant cells. In the white matter of the spinal cord were numerous well-defined, clear vacuoles (Wallerian degeneration). The association of the clinical history and pathological findings allowed the diagnosis of compressive myelopathy associated with pyogranulomatous reaction to the oily adjuvant of the foot-and-mouth disease vaccine, in this case, due to its inadequate application.(AU)

São descritos casos de síndrome de compressão medular, associada a granulomas pós-vacinais, em bovinos Nelore, provenientes de uma propriedade em Minas Gerais. Esses bovinos apresentavam ataxia e paresia bilateral dos membros pélvicos, que evoluiu para paralisia e decúbito esternal. Na necropsia, áreas focalmente extensas da musculatura na região torácica dorsal (músculo longissimus dorsi) eram substituídas por numerosos piogranulomas, separados por tecido brancacento e firme (tecido conjuntivo fibroso). Ao corte, alguns nódulos continham material amarelado e viscoso (exsudato purulento) ou material esbranquiçado e fluido (sugestivo de adjuvante de vacina). No canal medular das vértebras subjacentes, havia granulomas idênticos aos observados no tecido muscular. Histologicamente, os piogranulomas continham, no centro, vacúolo, bem delimitado e arredondado (consistente com o espaço deixado pela gotícula de lipídio do adjuvante), circundado por variável quantidade de neutrófilos degenerados e íntegros e, mais externamente, por numerosos macrófagos epitelioides e algumas células gigantes multinucleadas. Nas áreas da medula espinhal, circundadas pelos granulomas, numerosos vacúolos, bem definidos, eram observados na substância branca (degeneração walleriana). A associação do histórico clínico e de achados patológicos permitiu o diagnóstico de mielopatia compressiva associada à reação granulomatosa ao adjuvante oleoso da vacina contra febre aftosa, no caso, induzida pela aplicação inadequada da vacina.(AU)

Evaluation of different sites for blood collection for ß-hydroxybutyrate assessment in dairy cows using hand-held meter / Avaliação de diferentes locais de coleta de sangue para avaliação de ß-hidroxibutirato em vacas de leite usando aparelho portátil automático

Cetose subclínica é uma grande preocupação em rebanhos leiteiros, e seu diagnóstico e prevenção podem ter um grande impacto na saúde animal. Este estudo comparou quatro locais diferentes para a coleta de amostras de sangue (jugular, veias mamárias e coccígeas e ponta da cauda) para medição de ß-hidroxibutirato (BHBA), usando-se um medidor portátil automático. Foram utilizadas seis vacas Holandesas, e a coleta de sangue foi feita no segundo, quinto, 10º, 15º e 21º dias pós-parto. Os resultados do medidor portátil foram semelhantes aos resultados do laboratório e apresentaram uma correlação forte de 0,83. As concentrações séricas de BHBA nas amostras de sangue coletadas na ponta da cauda, na jugular e na coccígea foram semelhantes. No entanto, o sangue retirado da veia mamária tinha uma concentração mais baixa. Portanto, as amostras de sangue para aferição de BHBA podem ser recolhidas nas veias jugular e coccígeas e na ponta da cauda, sendo as duas últimas as opções mais fáceis para monitorar o BHBA em rebanho leiteiro.(AU)

Frequency of microorganisms isolated at different stages of lactation and milk production loss associated with somatic cell count and to mastitis-causing pathogens / Frequência de microrganismos isolados em diferentes fases da lactação e perda de produção de leite associada à contagem de células somáticas e aos patógenos causadores de mastite

The aim of this study was to evaluate the frequency of isolation of agents causing subclinical mastitis in a herd and to estimate production losses associated with SCC> 200,000cells/mL. Three 7-day interval microbiological cultures were performed in all lactating animals from the same farm that was evaluated from June to July. To evaluate the negative and positive isolation frequencies between the lactation phases, a Chi-square test was performed. Simple linear regressions were performed to evaluate the lactation curve of animals grouped by pathogens isolated from negative cows in the microbiological culture and with SCC <200,000cells/mL. To estimate the production losses between the groups, regression coefficients were used. Results found in this experiment were: Culture-negative cows with SCC ≥ 200,000cells/mL, cows testing positive in milk culture, with SCC <200,000cells/mL and cows testing positive in milk culture, with SCC ≥ 200,000cells/mL. Milk production was -3.5; -0.5 and -4.27kg, respectively, when compared to culture-negative cows with SCC <200,000cells/mL. Cows infected with yeast cells, Coagulase-negative staphylococci (CNS), Staphylococcus aureus and environmental streptococci produced -3.42; -0.5; -0.168 and -2.5kg of milk when compared to culture-negative cows with SCC <200,000cells/mL. SCC indicates an inflammatory reaction in the mammary gland and it is directly associated with milk production losses and with presence of microorganisms in the mammary gland.(AU)

O objetivo deste estudo foi avaliar a frequência de isolamento de agentes causadores de mastite subclínica em um rebanho e estimar as perdas de produção associadas com CCS>200.000 cél./mL. Três cultivos microbiológicos intervalados por sete dias foram realizados em todos os animais em lactação da propriedade avaliada, no período de junho a julho. Para avaliar as frequências de isolamento negativo e positivo entre as fases da lactação, foi realizado um teste de qui-quadrado. Foram realizadas regressões lineares simples para avaliar a curva de lactação dos animais agrupados por patógenos isolados em relação a vacas negativas na cultura microbiológica e com CCS < 200.000 cél./mL. Os coeficientes das regressões foram utilizados para estimar as perdas de produção entre os grupos. Vacas com resultado negativo na microbiologia, mas com CCS ≥ 200.000 cél./mL, positivas na microbiologia com CCS < 200.000 cél./mL e positivas com CCS ≥ 200.000 cél./mL, produziram por dia, respectivamente, -3,5; -0,5 e -4,27kg de leite em relação às vacas negativas com CCS < 200.000 cél./mL. Vacas infectadas com células leveduriformes, Staphylococcus coagulase negativa, Staphylococcus aureus e Streptococcus ambientais produziram, respectivamente, -3,42; -0,5; -0,168 e -2,5kg de leite, comparadas a vacas negativas com CCS < 200.000 cél./mL. A CCS, indicativa de reação inflamatória, encontra-se diretamente associada às perdas de produção de leite, assim como a presença do microrganismo na glândula mamária.(AU)

Expression of hepatic genes related to energy metabolism during the transition period of Holstein and F1 Holstein-Gir cows.

The aim of this study was to investigate the expression of genes encoding enzymes and other factors involved with carbohydrate and lipid metabolism in the liver of 2 genetic groups of dairy cows during the transition period. We analyzed the expression of glucose-6-phosphatase (G6PC), cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), methylmalonyl-CoA mutase (MUT), ß-hydroxybutyrate dehydrogenase-2 (BDH2), acetyl-CoA carboxylase (ACC), carnitine palmitoyltransferase-2 (CPT2), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), glucose transporter-2 (SLC2A2), and the transcription factor peroxisome proliferator-activated receptor α (PPARA). Blood concentrations of glucose, nonesterified fatty acids, and ß-hydroxybutyrate were also determined. Liver biopsies and blood samples were taken at d 15 prepartum and at d 6, 21, 36, 51, and 66 postpartum from Holsteins (n = 6) and F1 Holstein-Gir (n = 6) cows. Cows were kept under the same prepartum and postpartum management conditions. The results showed that the expression of G6PC, PEPCK-C, BDH2, ACC, CPT2, HMGCR, SLC2A2, and PPARA genes did not differ between genetic groups. Except for PEPCK-C, no interaction between genetic groups and the experimental period was observed. Within both groups of cows, G6PC and PEPCK-C gene expression decreased when comparing prepartum gene expression with 21 and 36 DIM, and increased in d 51 postpartum. MUT mRNA levels differed between the 2 genetic groups and displayed a significant increase after d 36 postpartum, whereas mRNA levels of HMGCR tended to increase when comparing d 21 and 36 to d 51 postpartum. Glucose concentrations also differed between genetic groups, being significantly higher in the plasma of F1 Holstein-Gir cows than in Holstein cows, but no differences were found within each group during the analysis period. ß-Hydroxybutyrate and nonesterified fatty acid concentrations did not differ between genetic groups, but displayed increased levels from prepartum to d 6 and 21 postpartum. Our results indicated that expression in the liver of genes involved with glucose and fatty acid metabolism were similar in both groups of cows and significant differences were observed between the 2 groups in the expression of MUT, a gene involved in propionate metabolism.

Mineral profile of crossbred F 1 Holstein x Gyr dairy cows during the transition period in summer and winter / Perfil mineral de vacas F1 Holandês x Gir durante o período de transição no verão e inverno

The transition period is often a great challenge for dairy cows and mineral imbalances are frequent. With the aim to better understand the mineral profile of F1 Holstein x Gyr dairy cows and their performances under the different conditions of summer and winter, we collected blood samples to measure calcium, magnesium and phosphorus. Samplings were performed during summer and winter, on 15 and 13 pluriparous F1 Holstein x Gyr dairy cows, respectively. Blood sampling started 4 weeks prior to the expected calving date until 30 days postpartum. The mean concentrations of all three minerals had a different pattern during the transition period in each season, representing the interaction time x season. Calcium concentration was lower in winter and more animals suffered from subclinical hypocalcemia (100%) then in summer (38.46%). Magnesium concentration was also lower in winter and 46.67% of animals had hypomagnesemia, contributing for the higher hypocalcemia frequency observed in the same season. A high proportion of animals had hyperphosphatemia what can represent an environmental problem and more attention should be given to it. The high frequency of animals with subclinical hypocalcemia is alarming once that can lead to greater consequences.(AU)

O período de transição é uma fase de grandes desafios para vacas leiteiras, e desequilíbrios minerais são frequentes. O objetivo ao desenvolver este trabalho foi de entender melhor o perfil mineral de vacas leiteiras F1 Holandês x Gir e suas performances sob as diferentes condições de verão e inverno. Para isso, foram mensurados cálcio, magnésio e fósforo sanguíneo. As coletas de sangue foram realizadas durante os períodos de verão e inverno, e utilizaram-se, respectivamente, 15 e 13 vacas leiteiras pluríparas, todas F1 Holandês x Gir. As coletas de sangue começaram quatro semanas antes da data prevista do parto até 30 dias pós-parto. As concentrações médias e o padrão de variação dos três minerais foram distintos em cada estação do ano, representando a interação tempo de coleta x estação do ano. A concentração de cálcio foi menor no inverno, período em que todos os animais apresentaram hipocalcemia subclínica, enquanto no verão 38,46% apresentaram essa condição. A concentração de magnésio foi maior no verão e nenhum animal teve hipomagnesemia, enquanto no inverno 46,67% dos animais apresentaram hipomagnesemia subclínica, contribuindo para a maior frequência de hipocalcemia observada no inverno. Uma alta proporção de animais teve hiperfosfatemia, o que pode representar um problema ambiental. A alta frequência de animais com hipocalcemia subclínica é alarmante principalmente devido às consequências geradas por essa condição.(AU)

Estimativa das perdas de produção leiteira em vacas mestiças Holandês x Zebu com mastite subclínica baseada em duas metodologias de análise / Comparison of two methodologies to estimate losses of milk production in crossbred Holstein x Zebu cows with sub-clinical mastitis

Contagem de células somáticas (CCS) e produção de leite de vacas mestiças Holandês x Gir foram utilizadas para avaliação da perda de produção de leite estimada por duas metodologias, baseadas na CCS média da lactação total encerrada ou na CCS e nas pesagens de leite em diferentes estágios de lactação. Nas primíparas consideradas com mastite subclínica (CCS ≥ 200.000 células mL-1), a perda de produção na lactação total, avaliada pela CCS média da lactação, foi de 814kg. Para as multíparas, não houve diferença na produção de leite entre vacas com e sem MSC com base na CCS média da lactação. A estimativa avaliada por meio de testes mensais de CCS e pesagens de leite em diferentes estágios de lactação, balanceada pela prevalência de mastite subclínica do mês foi de 917,9kg para primíparas e 1178,9kg para multíparas. A contraposição da produção de leite com a CCS em diferentes estágios da lactação evidenciou maior perda de produção em relação à observação da CCS média da lactação. A perda de produção de leite de vacas baseada na CCS média de toda a lactação foi subestimada quando comparada à contraposição da produção de leite com CCS em diferentes estágios da lactação.(AU)

Somatic cell count (SCC) and milk production of crossbred Holstein x Gir were used to evaluate the estimated loss of milk production two methodologies, based on the average SCC of total closed lactation, or average SCC and weighing milk at different stages of lactation. In primiparous with SCC mL ≥200,000 cells-1 production loss in the total lactation, evaluated by the average lactation SCC, was 814 kilograms. For multiparous, there was no difference in milk production between cows with and without SCM based on the SCC media of lactation. The estimate of lost production assessed through monthly testing of SCC and milk weighing at different stages of lactation, balanced by the prevalence of subclinical mastitis, was 917.9kg for primiparous and 1178.9kg for multiparous. The estimative of milk production with CCS at different stages of lactation showed greater loss of milk production when compared to the estimative based on the average SCC throughout the period of lactation. The milk production loss method based on the average somatic cell count of the whole lactation was underestimated when compared to the method based on average SCC in different stages of lactation.(AU)

Estudo longitudinal da mastite subclínica e produção de leite em um rebanho mestiço Holandês-Zebu criado em sistema semi-intensivo / Longitudinal study of subclinical mastitis and milk production on crossbred Holstein x Zebu cattle, housed in a semi-intensive system

Acompanhou-se durante 15 meses um rebanho leiteiro, composto por diferentes graus de sangue Holandês-Zebu (HZ), em sistema semi-intensivo. Objetivou-se avaliar o comportamento longitudinal da contagem de células somáticas (CCS) e a influência da mastite subclínica (MS) na produção total e no pico de produção de leite de vacas mestiças HZ. Inicialmente, coletaram-se amostras de leite individual para análise microbiológica, a fim de identificar o perfil de patógenos causadores de mastite. Realizou-se mensalmente a CCS com o intuito de monitorar a MS. Semanalmente, avaliou-se a produção de leite. Para avaliar o efeito da CCS sobre a produção de leite, as vacas foram divididas em dois grupos, <200.000 e ≥200.000 células/mL...

A herd of dairy cattle with different crossbreeding Holstein x Zebu (HZ), housed in a semi-intensive production system, was monitored for 15 months. We aimed to evaluate the longitudinal behavior of somatic cell count (SCC) and the influence of subclinical mastitis (SM) on the milk yield and on the peak yield of crossbred HZ dairy cows. Initially, individual milk samples were collected for microbiological analysis for identification of mastitis pathogens. The SCC was performed monthly to monitor subclinical mastitis. Additionally, milk production was evaluated weekly. To evaluate the effects of SCC on milk production, the cows were identified as falling into two groups: <200.000 and ≥200.000 cells/mL...

Energetic status of crossbreed dairy cows during transition period in two different seasons / Perfil energético de vacas leiteiras mestiças no período de transição em duas estações do ano

We used 31 crossbreed dairy cows to compare the energetic profile in summer and winter. Blood samples were taken weekly prepartum, at calving and on days 2, 5, 10, 15, 21 and 30 postpartum. All metabolic indicators analyzed were influenced by the physiological status. The glucose concentrations were higher during winter while the triglyceride concentrations and lactate dehydrogenase (LDH) were higher in the summer. The season influenced the concentrations of cholesterol, AST and GGT, showing a different pattern between summer and winter. Non-esterified fatty acids (NEFA) and beta-hidroxibutirate (BHB) were not influenced by the season. Cows that calved during winter had a greater body condition score (BCS) and lost more BCS until calving. During summer, 32.26% of the animals and 29.03% during winter had NEFA concentrations above the optimum level and 22.58% of the animals in summer and 19.35% in the winter had subclinical ketosis at some point during the transition period, making then more susceptible to diseases.

Foram utilizadas 31 vacas leiteiras mestiças para comparar o perfil energético em duas estações, verão e inverno. Amostras de sangue foram colhidas semanalmente durante o pré-parto, no dia do parto e nos dias dois, cinco, 10, 15, 21 e 30 do pós-parto. Todos os metabólitos analisados foram influenciados pelo estádio fisiológico. As concentrações de glicose foram maiores no inverno, enquanto as concentrações de triglicérides e lactato desidrogenase (LDH) foram maiores no verão. As concentrações de colesterol, AST e GGT mostraram um padrão de comportamento diferente entre o verão e o inverno. Ácidos graxos não esterificados (NEFA) e beta-hidroxibutirato (BHB) não foram influenciados pela estação do ano. As vacas que pariram durante o inverno tinham um escore de condição corporal (ECC) maior e perderam mais ECC até o parto. No verão, 32,26% e, no inverno, 29,03% dos animais apresentaram concentrações de NEFA acima do recomendado no pré-parto; 22,58% dos animais no verão e 19,35% no inverno tiveram cetose subclínica em algum momento do período de transição, tornando-os mais suscetíveis a outras doenças.

Effects of milk replacer feeding strategies on performance, ruminal development, and metabolism of dairy calves.

Performance, rumen development, and metabolism of male Holstein calves (n=54) were evaluated according to 1 of 3 liquid feeding strategies: 4 L of milk replacer (MR)/d until 60 d old (4 L-60 d), 6L of MR/d until 29 d old and 4 L/d from 30 to 60 d (6L-29 d/4 L-60 d), or 6L of MR/day until 60 d old (60 d-6L). Water and starter were provided ad libitum. Intakes of MR and starter were monitored daily and body weight (BW) weekly. Blood samples for glucose and insulin concentrations and ruminal content samples for volatile fatty acids and ruminal ammonia concentrations were collected at 15, 30, 45, 60, 75, and 90 d of age. Six calves on each treatment were euthanized at 30, 60, and 90 d of age. Empty weights of forestomach and abomasum, papillae length, and mitotic index were measured. Average MR intake/d (expressed as a percent of BW) was greater for calves receiving 6L/d than for those receiving 4 L/d until 30 d of age. Calves on the 6 L-29 d/4 L-60 d had the smallest MR intake from 30 to 60 d old, followed by the 4 L-60 d and 6L-60 d treatments. Starter intake (kg of dry matter/day) did not differ between groups. It increased from 0.065 kg/d in the first month to 0.386 kg/d in the second month, and to 2.065 kg/d after weaning. Weight gain was greater for calves fed more MR in the first month, but no difference was observed during the second month. After weaning, 6L-60 d calves had greater rate of weight gain than others and were heavier at 30, 60, and 90 d of age. Weight of empty forestomachs, ruminal pH, and ammoniac nitrogen concentration were not different among groups. Propionate concentration was lower for 6 L-60 d calves, but acetate and butyrate concentrations were not influenced by MR feeding strategy. Calves fed more MR until d 30 had greater ruminal epithelium mitotic index. The different MR feeding strategies did not influence papillae length or ruminal epithelium thickness. Lesions such as ruminal parakeratosis or hyperkeratosis were not observed. The MR feeding strategy did not affect glucose concentration, but insulin was higher in 6L-60 d calves than in the other groups. Glucose concentration increased with age, whereas insulin decreased until 45 d old, and then started to increase until 90 d. In conclusion, MR feeding strategy did not influence ruminal development. Feeding calves 6 L of MR/d over 60 d resulted in greater rate of weight gain without negative effects on starter intake or forestomach development. The weight advantage that 6L-60 d calves obtained preweaning was maintained until 90 d of age.

Vacinação com Escherichia coli J5 no pré-parto e ocorrência de mastite e produção de leite de vacas mestiças leiteiras / Escherichia coli J5 vaccination during pre-calving and mastitis and milk production of crossbred cows

Avaliaram-se a utilização da vacina Escherichia coli J5 no período pré-parto e a ocorrência de mastite e de produção de leite. Foram utilizadas 93 vacas, sendo 43 vacinadas e 50 não vacinadas. Para a análise dos dados de produção e CCS (contagem de células somáticas), utilizou-se delineamento inteiramente ao acaso em sistemas de parcelas subdivididas. Os dados de CCS e duração de casos clínicos de mastite foram transformados em Log10CCS. Para as médias de CCS e a duração de casos clínicos, usou-se o teste t. Para comparações de médias de recidivas de casos clínicos, usou-se o teste de Mann-Whitney. Para frequência de microrganismos e de mastite subclínica, usou-se o teste de qui-quadrado. A interação dessas variáveis foi analisada pelo teste de McNemar. Não houve redução na prevalência de infecções por coliformes entre a secagem e o parto nos dois grupos. A duração total dos casos clínicos de mastite em animais que apresentaram mastite clínica foi menor em vacas vacinadas. O número de episódios clínicos e a intensidade dos casos clínicos não diferiu entre os grupos. A prevalência de animais com mastite subclínica no pós-parto e a (CCS) nos 100 primeiros dias de lactação foram mais baixas no grupo de animais vacinados. Não foi observada diferença na produção de leite entre os grupos. A vacinação de vacas com E. coli J5 melhora a saúde da glândula mamária de vacas leiteiras e, consequentemente, reduz a prevalência de animais com mastite subclínica no pós-parto, bem como a duração dos casos clínicos de mastite e a CCS nos 100 primeiros dias de lactação.

The effect of immunization with Escherichia coli J5 vaccine in the pre-partum on the occurrence of mastitis and milk production in crossbred dairy cows was evaluated. Ninety-three cows were used as follows: forty-three were vaccinated and fifty cows were unvaccinated. For the production analysis, data and CCS were used in a completely randomized split-plot system. CCS data and duration of clinical cases of mastitis were transformed into Log10CCS. For the CSS averages and duration of clinical cases we used the t test. For comparisons of means of recurrences of clinical cases we used the Mann-Whitney test. For frequency of subclinical mastitis organisms and we used the chi-square test. The interaction of these variables was analyzed using the McNemar test. There was no reduction in the prevalence of infections caused by coliforms between drying-off and parturition in both groups. The total duration of clinical mastitis in animals with clinical mastitis was lower in vaccinated than unvaccinated cows. The number of clinical episodes and intensity of clinical cases did not differ between groups. The prevalence of animals with subclinical mastitis at postpartum and somatic cell count (SCC) in the first 100 days of lactation was lower in vaccinated than unvaccinated cows. However, there was no difference in milk production between groups. Vaccination of cows with E. coli J5 improves mammary gland health by reducing the prevalence of animals with subclinical mastitis at postpartum, as well as the duration of the clinical cases of mastitis and SCC in the first 100 days of lactation.

Utilização da vacina Escherichia coli J5 na imunização de novilhas leiteiras contra mastites causadas por E. coli / Use of an Escherichia coli J5 vaccine on immunization of dairy heifers against mastitis caused by E. coli

Avaliou-se a eficácia da vacina E.coli J5 na prevenção e no controle de mastites causadas por E.coli por meio da análise da prevalência de infecções intramamárias após o parto, ocorrência e intensidade de casos clínicos de mastite nos primeiros 100 dias de lactação, influência na contagem de células somáticas (CCS) e produção de leite. As novilhas, n=131, foram distribuídas em três grupos de animais - vacinados três vezes, vacinados duas vezes e não vacinados. As imunizações ocorreram 60 dias antes do parto, 30 dias antes do parto e na primeira semana pós-parto, esta última só para o grupo de três vacinações. Foram coletadas amostras de leite para diagnóstico microbiológico e avaliação da CCS, e registrados os dados relacionados à ocorrência e à intensidade dos casos clínicos e à produção de leite nos primeiros 100 dias de lactação. Não houve redução na prevalência de E.coli no pós-parto de novilhas vacinadas, e houve redução na ocorrência de casos clínicos por E.coli em novilhas vacinadas. Não foram observadas diferenças entre grupos com relação à CCS. Novilhas vacinadas com as três doses apresentaram maior produção de leite. A vacinação com E.coli J5 foi eficaz em reduzir a ocorrência de casos clínicos nos primeiros 100 dias da lactação, mas não interferiu na prevalência de infecções intramamárias após o parto, na intensidade de casos clínicos e na CCS.

Immunization of dairy heifers with E.coli J5 vaccine in order to prevent and control mastitis caused by E.coli was evaluated. Prevalence of postpartum intramammary infections by this agent; clinical mastitis occurrence and severity in the first 100 days of lactation, and its influence on somatic cell counts (SCC) and milk yield were analyzed. Heifers (n=131) were randomly assigned into three groups of vaccinated and unvaccinated animals. Immunizations occurred at 60 days prepartum, 30 days prepartum and in the first week after calving. Milk samples were collected for microbiological diagnosis and SCC evaluation, and data related to clinical mastitis occurrence; its severity and milk yield were recorded. No reduction in prevalence of postpartum intramammary infections caused by E.coli was observed in vaccinated heifers. Vaccinated heifers had less clinical mastitis than the unvaccinated group. Milk SCC did not differ between the experimental groups. Milk yield was higher in vaccinated animals. Immunization with the E.coli J5 vaccine was effective in reducing the occurrence of clinical mastitis and increase in milk yield in the first 100 days of lactation but did not affect SCC, prevalence of intramammary infections and severity of clinical mastitis after calving.

Pancreatite crônica intersticial e caquexia causada por Eurytrema coelomaticum em vaca Nelore / Chronic interstitial pancreatitis and chronic wasting disease caused by Eurytrema coelomaticum in Nelore cow

A euritrematose bovina, causada por Eurytrema coelomaticum, tem sido relatada no Brasil. A doença pode afetar animais domésticos, incluindo ruminantes. Estes parasitos geralmente vivem nos ductos pancreáticos e ocasionalmente nos ductos biliares. Este estudo relata um quadro de caquexia em um bovino parasitado por E. coelomaticum proveniente de um rebanho de gado de corte localizado no Estado de Minas Gerais. O animal acometido apresentou perda progressiva de peso, glicosúria e cetonúria. Na necropsia o pâncreas apresentava-se diminuído de tamanho, brancacento, intensa e difusamente firme (fibrose). Vários ductos apresentavam-se dilatados e repletos de Eurytrema. Microscopicamente foi observada destruição extensa do parênquima pancreático e fibrose, ovos e parasitas intralesionais, hiperplasia ductal e inflamação multifocal crônica. Este relato descreve a perda progressiva de peso e pancreatite crônica associada a E. coelomaticum em bovino de corte no Estado de Minas Gerais.

Citologia de medula óssea das primeiras seis semanas de vida de bovinos da raça Holandesa / Cytology of the bone marrow of the first six weeks of life of Holstein cattle

The possible changes in the bone marrow associated with hematological changes in peripheral blood during the first six weeks of life in cattle were evaluated. To this purpose, blood samples were evaluated at 2, 4, 7, 10, 14, 21, 28, 35, and 42 days of life, and cytologic examination of bone marrow at 2, 7, 21, and 42 days of life in 10 Holstein calves. The bone marrow examination showed, in different times, myeloid:erythroid ratio from 0.60 to 0.69. The erythroid lineage distribution remained pyramidal, with concentration of precursor cells above the initial reference values for adult cattle. Proliferation pool of myeloid lineage also remained above the reference range, with decreases of concentrations in the third and sixth weeks. In the lymphoid lineage, the concentration of lymphocytes showed a decrease in the first three weeks, with a tendency to rise in the sixth week.

Epidemiologic aspects of an outbreak of Trypanosoma vivax in a dairy cattle herd in Minas Gerais state, Brazil.

The aim of this study was to assess the epidemiological situation of bovine trypanosomiasis caused by Trypanosoma vivax in a dairy cattle herd from Igarapé, Minas Gerais state, Brazil. The herd was monitored from September 2007 to February 2009 by sampling blood for determination of packed cell volume (PCV), microhaematocrit centrifugation test of parasitaemia (MHCT), serology (IFA), morphological identification of T. vivax and molecular diagnosis by polymerase chain reaction (PCR). During all the experimental period, 25 animals were MHCT and PCR positive, considering that in each sample collection a mean of 70 animals was evaluated. The morphometric characteristics of trypomastigote forms confirmed the infection by T. vivax. The seroprevalence ranged from 7.4% in September 2007 to 48% in February 2009, and the highest incidence observed could be correlated with an increased population of Stomoxys calcitrans flies in that region. Anaemia was the most important change found in infected animals, which showed lower averages of PCV than parasitologically negative animals (p<0.0001). Infected individuals showed lower averages of PCV than parasitologically negative animals (p<0.0001), indicating higher anaemia in the former compared with the latter group.

Taxa de sudação e parâmetros histológicos de bovinos submetidos ao estresse calórico / Sweat rate and histological parameters of cattle submitted to heat stress

Caracterizaram-se o pelame, a taxa de sudação e os parâmetros histológicos de 71 bovinos F2 (½ Gir x ½ Holandês), 39 machos e 32 fêmeas, entre 14 e 20 meses de idade, submetidos a condições de termoneutralidade (22ºC e 70 por cento de umidade relativa - UR) e ao estresse calórico (42ºC e 60 por cento UR). Os tratamentos foram realizados nas estações de verão e inverno em câmara bioclimática. O comprimento dos pelos e a espessura da capa foram maiores no inverno que no verão, sendo de 1,58 e 1,04cm e 5,31 e 3,91mm, respectivamente (P<0,05). A histologia da pele mostrou que, no verão, a área da glândula sudorípara e a distância da glândula ao epitélio foram menores que no inverno, sendo de 2589 e 4051µm e 294 e 344µm, respectivamente (P<0,05). Concluiu-se que a estação do ano influencia as características de pelame, o posicionamento e a atividade das glândulas sudoríparas de forma a maximizar o controle da homeostase térmica.

Coat thickness, sweat rate, and histological parameters were characterized in 39 males and 32 females crossbred cattle (½ Holstein x ½ Gir), averaging 14 to 20 months of age, submitted to thermoneutrality (22ºC and 70 percent of relative humidity - RH) and heat stress (42ºC and 60 percent RH) in summer and winter in a climatic chamber. Fur length and coat thickness were significantly higher in summer than winter, 1.58 and 1.04cm and 5.31 and 3.91mm, respectively (P<0.05). Skin histology showed that sweat gland area and distance of gland to epithelium was shorter in summer than in winter, 2,589 and 4,051µm and 294 and 344µm, respectively (P<0.05). It was concluded that the season influenced the coat thickness, the sweat glands disposal and activity to maximize thermic homeostasis control.

Parâmetros clínicos, hematológicos, bioquímicos e hormonais de bovinos submetidos ao estresse calórico / Clinical, hematological, biochemical, and hormonal parameters of cattle submitted to heat stress

Caracterizaram-se as respostas clínicas, hematológicas, bioquímicas e hormonais de 71 bovinos F2 (½ Gir x ½ Holandês), 39 machos e 32 fêmeas, entre 14 e 20 meses de idade, submetidos a condições de termoneutralidade (22ºC a 70 por cento de umidade relativa) e ao estresse calórico (42ºC e 60 por cento de umidade relativa). Os tratamentos foram realizados nas estações de verão e inverno em câmara bioclimática. Ao exame clínico, todos os animais apresentaram salivação e retração de globo ocular. Os animais apresentaram aumento do número de eritrócitos, concentração de hemoglobina, hematócrito, proteínas totais, ureia, creatinina, sódio, potássio, cloretos, cortisol, pH e densidade urinária e matéria seca das fezes no período de estresse calórico (P<0,05). O aumento de todas essas variáveis foi mais acentuado no verão (P<0,05). Os valores de γ-glutamil transferase e aspatato aminotransferase aumentaram no período da tarde no verão (P<0,05), e a concentração sérica de potássio foi constante entre estações (P>0,05). Concluiu-se que as variáveis hematológicas, bioquímicas e hormonais, bem como as características fenotípicas, revelaram-se importantes para caracterizar o estresse calórico em bovinos.

Clinical, haemathological, biochemical, and hormonal parameters were characterized in 39 males and 32 females crossbred cattle (½ Holstein x ½ Gir), averaging 14 to 20 months of age, submitted to thermoneutrality (22ºC and 70 percent of RH) and heat stress (42ºC and 60 percent RH) in summer and winter in climatic chamber. At clinical examination, all animals presented salivation and ocular globe retraction. Under heat stress, animals increased erythrocytes count, hemoglobin total concentration, hematocrit, concentraction of total proteins, urea, creatinin, sodium, potassium, chlorides, cortisol, urinary pH and density, and dry matter of feces (P<0.05). The increase of all these variables was more evident in the summer. The values of γ-glutamil transferase and aspartate aminotransferase increased under stress only in the summer (P<0.05), been potassium blood concentration constant during the seasons (P>0.05). It was concluded that hematology, biochemical, and hormonal parameters are important to characterize the heat stress in cattle.

Clinicopathologic features of experimental Clostridium perfringens type D enterotoxemia in cattle.

This study was designed to experimentally reproduce enterotoxemia by Clostridium perfringens type D in cattle and to characterize the clinicopathologic findings of this disease. Fourteen 9-month-old calves were inoculated intraduodenally according to the following schedule: group 1 (n = 4), C. perfringens type D whole culture; group 2 (n = 3), C. perfringens type D washed cells; group 3 (n = 5), C. perfringens type D filtered and concentrated supernatant; group 4 (n = 2), sterile, nontoxic culture medium. In addition, all animals received a 20% starch solution in the abomasum. Ten animals from groups 1 (4/4), 2 (3/3), and 3 (3/5) showed severe respiratory and neurologic signs. Gross findings were observed in these 10 animals and consisted of acute pulmonary edema, excessive protein-rich pericardial fluid, watery contents in the small intestine, and multifocal petechial hemorrhages on the jejunal mucosa. The brain of one animal of group 2 that survived for 8 days showed multifocal, bilateral, and symmetric encephalomalacia in the corpus striatum. The most striking histologic changes consisted of perivascular high protein edema in the brain, and alveolar and interstitial proteinaceous pulmonary edema. The animal that survived for 8 days and that had gross lesions in the corpus striatum showed histologically severe, focal necrosis of this area, cerebellar peduncles, and thalamus. Koch's postulates have been met and these results show that experimental enterotoxemia by C. perfringens type D in cattle has similar clinical and pathologic characteristics to the natural and experimental disease in sheep.

Meningoencefalite por Herpesvirus bovino 5 em Minas Gerais: relato de caso clínico / Meningoencephalitis by Bovine herpesvirus 5 in Minas Gerais state: clinical case report

Relata-se um caso de meningoencefalite causada por Herpesvirus bovino 5 (BoHV-5) heritabilityem uma vaca com cinco anos de idade. O animal manifestou quadro clínico inicial de síndrome medular baixa, caracterizada por incoordenação dos membros pélvicos, sinais estes ainda não descritos para a enfermidade. Dentro de pouco tempo a doença evoluiu para síndrome cerebral, e o óbito ocorreu seis dias após o inicio dos sintomas. Na histopatologia, evidenciou-se meningoencefalite difusa, não supurada, e a confirmação do diagnóstico foi feita por reação em cadeia de polimerase e sequenciamento do segmento parcial da glicoproteína G do vírus. O trabalho confirma a presença do BoHV-5 em Minas Gerais, descreve características clínicas novas para a enfermidade e ressalta sua importância no diagnóstico diferencial das neuropatias bovinas.

A clinical case of meningoencephalitis by Bovine herpesvirus 5 (BoHV-5) in a five-year-old cow was reported. The disease began with low spinal cord signs, characterized by incoordination, and these symptoms had never been related to this illness before. Signs of a brain syndrome were observed and the cow died in six days. At the histopathology, a spread non-supurative meningoencephalitis was diagnosed, and the virus identification was made by PCR and partial sequence of the glycoprotein G. This study confirm the BoHV-5 presence in the State of Minas Gerais, Brazil, describes new clinic characteristics, and show the importance of the disease in the differentiate diagnosis with others bovine central nervous system affections.

Ocorrência de Trypanosoma vivax no estado de Minas Gerais / Occurrence of Trypanosoma vivax in Minas Gerais state, Brazil

A cow from Igarapé city, Minas Gerais state, Brazil, showing vision damage was referred at the Veterinary Hospital of the Universidade Federal de Minas Gerais. Clinical examination revealed anemia and a flagellated protozoan was observed in the blood smears obtained from the animal. The morphometric analysis demonstrated that the protozoan was Trypanosoma vivax. This is the first report of T. vivax occurrence in Minas Gerais state. An epidemiological investigation is currently being conducted on the farm and neighbor areas in order to estimate the parasite prevalence and the distribution of this trypanosomiasis in the region.