Effect of Saccharomyces cerevisiae byproducts on milk phagocyte function and milk production in mid-lactation cows / Efeito dos subprodutos de Saccharomyces cerevisiaena função de fagócitos lácteos e na produção de leite de vacas no meio do estágio da lactação

Saccharomyces cerevisiae is a supplement option for ruminants due to its ability to stimulate the immune system and productivity; however, there are few studies that demonstrate the effectiveness of this yeast in dairy cattle, especially regarding its effect on milk phagocyte function. Thus, this study examined the effect of two presentations of autolyzed S. cerevisiae on milk phagocyte function and milk production in healthy Holstein cows from the third to the fifth months of lactation with somatic cell count (SCC) less than 200,000 cells mL-1. Ten animals received cell wall-rich S. cerevisiae autolysate (WC 15 g animal day-1); 8 received the cytoplasm-rich extract (CYT 5 g animal day-1) and 7 received a diet without supplementation (C, control) for 60 days. Weekly oxidative metabolism analysis of milk leukocytes, production and milk constituents was carried out. The oxidative metabolism of milk leukocytes was higher in the WC group than in the C group between D32 and D48 (P≤ 0.05) and in the CYT group than in the C group between D24 and D40 (P≤ 0.05). The production and percentage of milk fat increased in CYT at D48 and D56. It is concluded that the CYT group had a greater effect on productivity, while on immunity the effect was intermediate, compared to the WC group, which was efficient in improving the immunity of the mammary gland.(AU)

Saccharomyces cerevisiae é uma opção de suplemento para ruminantes devido à sua capacidade de estimular o sistema imunológico e a produtividade; entretanto, ainda há poucos estudos que demonstrem a real eficácia das diferentes apresentações desta levedura em bovinos leiteiros, principalmente quanto ao seu efeito sobre a função dos fagócitos lácteos. Assim, o efeito de duas apresentações de S. cerevisiae autolisado na função fagocitária do leite e produção de leite de vacas da raça Holandes saudáveis entre o terceiro e quinto mês de lactação, com CCS inferior a 200.000 células mL-1. Para tanto, 10 animais receberam autolisado de S. cerevisiae ricos em parede celular (WC - 15 g animal dia-1); oito receberam o extrato rico em citoplasma (CYT - 5 g animal dia-1) e 7 receberam dieta sem suplementação (C - controle) por 60 dias. Análises do metabolismo oxidativo de leucócitos lácteos, produção de leite e constituintes do leite foram realizadas semanalmente. O metabolismo oxidativo dos leucócitos lácteos foi maior no grupo WC do que no grupo C entre D32 e D48 (P≤ 0,05) e no grupo CYT do que no grupo C entre D24 e D40 (P≤ 0,05). A produção de leite e a porcentagem de gordura do leite aumentaram no citoplasma (CYT) em D48 e D56. Concluiu-se que o grupo CYT teve um efeito maior na produtividade enquanto que na imunidade o efeito foi intermediário, comparando ao grupo WC que se mostrou eficiente na melhora da imunidade da glândula mamária.(AU)

The in vitro effects of n-3 fatty acids on immune response regulation of bovine ex vivo endometrial explants / Os efeitos in vitro dos ácidos graxos n-3 na regulação da resposta imune de explantes endometriais bovinos ex vivo

Fatty acids are considered metabolic intermediaries, although new facts indicate they also work as signaling molecules with different roles in the immune response. Based on that, in this study, we investigated the anti-inflammatory effects of n-3 polyunsaturated fatty acids (PUFAs) as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and α-linolenic acid (LNA) in ex vivo bovine endometrial explants. For this, two groups were formed: (1) LPS-challenged and (2) control, both to evaluate the accumulation of proinflammatory cytokines as interleukin 1ß (IL1B) and interleukin 6 (IL6). To develop the study, bovine female reproductive tracts from non-pregnant Angus heifers without evidence of reproductive diseases were selected. Endometrial explants were processed and treated for 24 h with EPA, DHA, and LNA in five different concentrations (0µM, 50µM, 100 µM, 200µM and 400 µM) and then, challenged with LPS for 24 h. Supernatants were collected to evaluate the concentration of IL1B and IL6 by ELISA. Explants treated with EPA from control groups reduced the concentrations of ILB (200µM) and IL6 (400 µM), and IL6 (50 µM; 100 µM) from the LPS-challenged group. DHA decreased the accumulation of IL1B and IL6 at 200 µM on explants from the LPS-challenged group, and 200 µM reduced IL6 from the control group. In contrast, explants treated with LNA only reduced the accumulation of IL1B to 400µM (from both groups). In conclusion, the EPA acid is the best anti-inflammatory option to decrease the concentration of both pro-inflammatory cytokines (IL1B and IL6) from LPS-challenged and control groups in bovine endometrial explants; while LNA evidence to be the last option to promote an anti-inflammatory response.(AU)

Os ácidos graxos são considerados intermediários metabólicos, embora novos fatos indiquem que eles também atuem como moléculas sinalizadoras com diferentes papéis na resposta imune. Dessa forma, este estudo investigou os efeitos anti-inflamatórios de ácidos graxos poliinsaturados n-3 (PUFAs) como ácido eicosapentaenóico (EPA), ácido docosahexaenóico (DHA) e ácido α-linolênico (LNA) em explantes endometriais ex vivo de bovinos. Para tal, o experimento foi divido em dois grupos: (1) Desafiado-LPS e (2) Controle, para que então pudesse avaliar o acúmulo de citocinas pró-inflamatórias como interleucina 1ß (IL1B) e interleucina 6 (IL6). Foram selecionados tratos reprodutivos de fêmeas bovinas de novilhas Angus não prenhes sem evidência de doenças reprodutivas. Explantes endometriais foram processados e tratados por 24h com EPA, DHA e LNA em cinco concentrações diferentes (0µM, 50µM, 100 µM, 200µM e 400 µM) e, em seguida, desafiados com LPS por mais 24h. Os sobrenadantes foram colhidos para avaliar a concentração de IL1B e IL6 pelo teste de ELISA. Os explantes tratados com EPA dos grupos de controle reduziram as concentrações de ILB (200 µM) e IL6 (400 µM) e no grupo desafiado com LPS houve redução das concentrações de IL6 (50 µM; 100 µM). Nos explantes do grupo desafiado com LPS, o DHA diminuiu o acúmulo de IL1B e IL6 nas concentrações de 200 µM, e no grupo controle reduziu IL6 nas concentrações de 200 µM, enquanto os explantes tratados com LNA reduziram apenas o acúmulo de IL1B a 400 µM (de ambos os grupos). Em conclusão, o ácido EPA provou ser a melhor opção anti-inflamatória para diminuir a concentração de ambas as citocinas pró-inflamatórias (IL1B e IL6) de grupos desafiados com LPS e controle em explantes endometriais bovinos; enquanto o LNA evidencia ser a opção menos viável para promover uma resposta anti-inflamatória.(AU)

Weaning at 30, 75 and 180 days: Comparison between immune responses of beef calves.

The interruption of the maternal-filial bond in young calves can alter the physiological responses due to increased stress at this moment. Therefore, we aimed to analyze the association between age at weaning and the immune responses of 64 beef calves weaned abruptly. The animals were distributed in three weaning (W) treatments: hyper-early (W30), early (W75) and conventional (W180). The treatments agree with the weaning ages used in cow-calf systems in South America. Blood samples were collected of all experimental animals on the day of weaning and days 1, 2 and 7 post-weaning day of the three treatments. Blood samples were used to analyze hematological variables, total plasma proteins (TPP), fibrinogen, serum amyloid A protein (SAA) and cortisol. The variables analyzed were influenced by the sampling day (P < 0.001) and the calf gender (P < 0.05), and an interaction between treatment x sampling day was observed. Over the study period, high serum cortisol levels were observed for W30 calves. The serum amyloid A protein was significantly influenced by sampling day. When compared to W180 calves, W30 and W75 animals showed prolonged concentrations in plasma fibrinogen. In addition, they presented neutrophilia and lymphopenia during the 180-187 days period, which resulted in a greater neutrophil:lymphocyte ratio (N:L ratio). Calf gender resulted in changes in the number of blood leukocytes (P < 0.05). This result provides an alert for weaning at an early age, indicating that different management strategies must be tested to minimize physiological instabilities in critical periods of the life of animals.

Innate and humoral immune parameters at delivery in colostrum and calves from heifers experimentally infected with Neospora caninum.

Neospora caninum is a leading cause of abortion in cattle worldwide. The study of the immune response against N. caninum is critical to understand its epidemiology, pathogenesis, diagnosis and, ultimately, in preventing and controlling bovine neosporosis. Herein, we determined the gene expression of innate immune components endosomal RNA-sensing TLRs, BMAP28 cathelicidin, TNF-α and IL-10 and characterized the variation in both IgG ratio and avidity at delivery in N. caninum-infected heifers challenged at day 210 of gestation, colostrum and their calves. Increased BMAP28 expression was observed not only in colostrum but also in peripheral blood mononuclear cells (PBMC) and umbilical cord of calves from N. caninum-infected heifers in comparison with mock-infected control group. In addition, statistically significant decrease of TLR7 and IL-10 expression levels were observed in umbilical cord, suggesting an attempt to avoid an exacerbated immune response against the parasite. At delivery, serum and colostrum samples from infected group evidenced specific IgG anti-N. caninum. Infected heifers showed IgG1/IgG2 ratios <1 and high avidity specific IgG. As expected, colostrum samples of these animals exhibited a high IgG1 concentration and elevated avidity values. Three out of four calves from N. caninum-infected heifers had specific IgG with IgG1/IgG2 ratios>1 and lower avidity values before colostrum intake. Interestingly, both IgG1/IgG2 ratios and avidity values increased in seropositive calves after colostrum intake. Overall, this study provides novel information on neonatal immunity in congenitally infected calves, which is essential to understand how the immune pathways could be manipulated or immune components could be employed in order to improve protection against neosporosis.

Spontaneous poisoning by Cestrum intermedium in dairy cattle / Intoxicação espontânea por Cestrum intermedium em bovinos de leite

Acute hepatotoxicity caused by plants poisoning is responsible for economic losses in farm animals in Brazil. Reports of Cestrum intermedium natural poisoning in cattle are not commonly described in Rio Grande do Sul (RS). This study aimed to document an outbreak of spontaneous C. intermedium poisoning in dairy cattle in the Central-Eastern Mesoregion of RS. Three nine-month-old Holstein and Jersey heifers were affected after they were placed in a small paddock with shortage forage. In this area, specimens of C. intermedium Sendtn with signs of consumption were observed. Morbidity and lethality rates were 100% and clinical courses ranged from 9 to 12 hours. At post mortem examination of the three heifers, there was predominance of acute liver lesions. The liver was moderately enlarged and on the cut surface there was a marked accentuation of the lobular pattern and hemorrhage. Inside the rumen, partially digested C. intermedium Sendtn leaves were observed. The histological aspects of the liver were mostly centrilobular coagulative necrosis and hemorrhage, frequently extended to the midzonal region. The immunohistochemistry technique was performed, in which the polyclonal antibody caspase 3 was used in liver fragments. Moderate to marked immunolabeling was observed in the cytoplasm and nucleus of hepatocytes, predominantly on the periphery of areas of hepatic necrosis indicating cell apoptosis. The diagnosis of C. intermedium Sendtn poisoning in dairy cattle in this study was based on epidemiological, clinical and anatomopathological findings. Since the C. intermedium poisoning is uncommon in dairy cattle, we are describing it for the first time in the Central-Eastern Mesoregion of RS, and represents a differential diagnosis of other acute toxic liver diseases in cattle.(AU)

Intoxicações por plantas que causam hepatotoxicidade aguda são responsáveis por prejuízos econômicos em animais de produção no Brasil. Relatos de intoxicações naturais por Cestrum intermedium em bovinos não são comumente descritos no Rio Grande do Sul (RS). Este trabalho teve como objetivo documentar um surto de intoxicação espontânea por C. intermedium em bovinos leiteiros ocorrido na região Centro-Oriental do RS. Três bovinos com nove meses de idade, das raças Holandês e Jersey, foram acometidos depois de serem introduzidos em um pequeno piquete com escassez de forragem. Nessa área foram observados exemplares de Cestrum intermedium Sendtn com sinais de consumo. As taxas de morbidade e letalidade foram de 100% e os cursos clínicos variaram de 9 a 12 horas. Na necropsia dos três bovinos, observou-se predomínio de lesões hepáticas agudas. O fígado dos animais acometidos estava moderadamente aumentado de tamanho e na superfície de corte havia marcada acentuação do padrão lobular e hemorragia. Na abertura do rúmen, foram observadas folhas de Cestrum intermedium Sendtn parcialmente digeridas. Histologicamente, o fígado apresentava necrose coagulativa centrolobular e hemorragia. Frequentemente, essas alterações se estendiam para a região mediozonal. Foi realizada a técnica de imuno-histoquímica, na qual utilizou-se o anticorpo policlonal caspase 3 em fragmentos de fígado. Notou-se marcação moderada a acentuada em citoplasma e núcleo de hepatócitos, predominantemente na periferia das áreas de necrose hepática indicando apoptose celular. O diagnóstico de intoxicação por Cestrum intermedium Sendtn nos bovinos leiteiros desse estudo, foi realizado com base nos achados epidemiológicos, clínicos e anatomopatológicos. A intoxicação por C. intermedium é incomum em bovinos leiteiros, sendo descrita pela primeira vez na região centro oriental do RS e representa um diagnóstico diferencial de outras hepatopatias tóxicas agudas.(AU)

Clinical, imaginological and pathological aspects of umbilical panvasculitis in calves: case report / Aspectos imaginológicos e clínico-patológicos de panvasculite umbilical em bezerro: relato de caso

The diagnosis of umbilical infections in neonates can be obtained from clinical signs, but the intracavitary involvement of structures and associated complications can be underestimated, compromising the establishment of adequate therapeutic approaches or prognosis. This case report presents the clinical, imaging, pathological and microbiological aspects of an umbilical infection in calves. Physical examination of the animal identified apathy, low body score, increased volume in the umbilical region and joints. The abdominal palpation identified firm structures in topography of the arteries and umbilical vein. Imaging examinations of the abdomen and joints were performed. Multiple, hyperechogenic focal structures have been identified in the liver, as well as cylindrical and firm structures in topography of the arteries and umbilical vein. In the joints, osteolytic changes, periosteal reactions, subchondral sclerosis and formation of osteophytes were seen. Umbilical panvasculitis triggered arthritis and an infectious process in the liver, the case being assessed as having an unfavorable prognosis and the animal being referred for euthanasia. At necropsy, multifocal abscesses were observed in the pleura, ribs, omentum, spleen and liver. There was granulomatous exudate in the urinary vesicle. The affected joints presented thickening of the joint capsule with the presence of exudat

O diagnóstico das infecções umbilicais em neonatos pode ser obtido a partir do exame clínico, porém o compro-metimento intracavitário das estruturas e as complicações associadas podem ser subestimados, comprometendo o estabeleci-mento de condutas terapêuticas ou prognósticos adequados. Apresenta-se nesse trabalho os aspectos clínicos, imaginológicos e patológicos de uma infecção umbilical em bezerro. No exame físico do animal identificou-se apatia, baixo escore corporal, aumento de volume na região umbilical e articulações e, em palpação abdominal, estruturas firmes em topografia das artérias e veia umbilical. Na avaliação ultrassonográfica abdominal identificou-se estruturas focais múltiplas, hiperecogênicas no fígado e estrutura bem definida, com parede hipoecoica e lúmen hiperecoico, estendendo-se de lobo hepático até porção cranial do anel umbilical. Na radiografia das articulações foram vistas alterações osteolíticas, reação periosteal, esclerose e formação de osteófitos, além do aumento de volume e radiopacidade de tecido moles adjacentes com presença de áreas radiolucentes, indi-cando presença gasosa local. Os sinais clínicos e os achados imaginológicos demonstraram a ocorrência de panvasculite umbi-lical que desencadeou um quadro de poliartrite séptica e processos infecciosos em diversos órgãos. O estudo imaginológico permitiu identificar onfaloflebite, grave acometimento de parênquima hepático e artrites sépticas, sendo o caso avaliado como tendo um prognóstico desfavorável e o animal eutanasiado. O tratamento conservador com antibioticoterapia prolongada e/ou a retirada ou marsupialização dos remanescentes umbilicais infectados podem ser utilizados em casos de onfaloflebites ou onfaloarterites. No entanto, esse procedimento não foi adotado devido ao comprometimento hepático e aos achados radio-gráficos que demonstraram ocorrência de osteoartrite séptica.

Clinical, imaginological and pathological aspects of umbilical panvasculitis in calves: case report / Aspectos imaginológicos e clínico-patológicos de panvasculite umbilical em bezerro: relato de caso

The diagnosis of umbilical infections in neonates can be obtained from clinical signs, but the intracavitary involvement of structures and associated complications can be underestimated, compromising the establishment of adequate therapeutic approaches or prognosis. This case report presents the clinical, imaging, pathological and microbiological aspects of an umbilical infection in calves. Physical examination of the animal identified apathy, low body score, increased volume in the umbilical region and joints. The abdominal palpation identified firm structures in topography of the arteries and umbilical vein. Imaging examinations of the abdomen and joints were performed. Multiple, hyperechogenic focal structures have been identified in the liver, as well as cylindrical and firm structures in topography of the arteries and umbilical vein. In the joints, osteolytic changes, periosteal reactions, subchondral sclerosis and formation of osteophytes were seen. Umbilical panvasculitis triggered arthritis and an infectious process in the liver, the case being assessed as having an unfavorable prognosis and the animal being referred for euthanasia. At necropsy, multifocal abscesses were observed in the pleura, ribs, omentum, spleen and liver. There was granulomatous exudate in the urinary vesicle. The affected joints presented thickening of the joint capsule with the presence of exudat(AU)

O diagnóstico das infecções umbilicais em neonatos pode ser obtido a partir do exame clínico, porém o compro-metimento intracavitário das estruturas e as complicações associadas podem ser subestimados, comprometendo o estabeleci-mento de condutas terapêuticas ou prognósticos adequados. Apresenta-se nesse trabalho os aspectos clínicos, imaginológicos e patológicos de uma infecção umbilical em bezerro. No exame físico do animal identificou-se apatia, baixo escore corporal, aumento de volume na região umbilical e articulações e, em palpação abdominal, estruturas firmes em topografia das artérias e veia umbilical. Na avaliação ultrassonográfica abdominal identificou-se estruturas focais múltiplas, hiperecogênicas no fígado e estrutura bem definida, com parede hipoecoica e lúmen hiperecoico, estendendo-se de lobo hepático até porção cranial do anel umbilical. Na radiografia das articulações foram vistas alterações osteolíticas, reação periosteal, esclerose e formação de osteófitos, além do aumento de volume e radiopacidade de tecido moles adjacentes com presença de áreas radiolucentes, indi-cando presença gasosa local. Os sinais clínicos e os achados imaginológicos demonstraram a ocorrência de panvasculite umbi-lical que desencadeou um quadro de poliartrite séptica e processos infecciosos em diversos órgãos. O estudo imaginológico permitiu identificar onfaloflebite, grave acometimento de parênquima hepático e artrites sépticas, sendo o caso avaliado como tendo um prognóstico desfavorável e o animal eutanasiado. O tratamento conservador com antibioticoterapia prolongada e/ou a retirada ou marsupialização dos remanescentes umbilicais infectados podem ser utilizados em casos de onfaloflebites ou onfaloarterites. No entanto, esse procedimento não foi adotado devido ao comprometimento hepático e aos achados radio-gráficos que demonstraram ocorrência de osteoartrite séptica.(AU)

Spontaneous poisoning by Cestrum intermedium in dairy cattle / Intoxicação espontânea por Cestrum intermedium em bovinos de leite

Acute hepatotoxicity caused by plants poisoning is responsible for economic losses in farm animals in Brazil. Reports of Cestrum intermedium natural poisoning in cattle are not commonly described in Rio Grande do Sul (RS). This study aimed to document an outbreak of spontaneous C. intermedium poisoning in dairy cattle in the Central-Eastern Mesoregion of RS. Three nine-month-old Holstein and Jersey heifers were affected after they were placed in a small paddock with shortage forage. In this area, specimens of C. intermedium Sendtn with signs of consumption were observed. Morbidity and lethality rates were 100% and clinical courses ranged from 9 to 12 hours. At post mortem examination of the three heifers, there was predominance of acute liver lesions. The liver was moderately enlarged and on the cut surface there was a marked accentuation of the lobular pattern and hemorrhage. Inside the rumen, partially digested C. intermedium Sendtn leaves were observed. The histological aspects of the liver were mostly centrilobular coagulative necrosis and hemorrhage, frequently extended to the midzonal region. The immunohistochemistry technique was performed, in which the polyclonal antibody caspase 3 was used in liver fragments. Moderate to marked immunolabeling was observed in the cytoplasm and nucleus of hepatocytes, predominantly on the periphery of areas of hepatic necrosis indicating cell apoptosis. The diagnosis of C. intermedium Sendtn poisoning in dairy cattle in this study was based on epidemiological, clinical and anatomopathological findings. Since the C. intermedium poisoning is uncommon in dairy cattle, we are describing it for the first time in the Central-Eastern Mesoregion of RS, and represents a differential diagnosis of other acute toxic liver diseases in cattle.(AU)

Intoxicações por plantas que causam hepatotoxicidade aguda são responsáveis por prejuízos econômicos em animais de produção no Brasil. Relatos de intoxicações naturais por Cestrum intermedium em bovinos não são comumente descritos no Rio Grande do Sul (RS). Este trabalho teve como objetivo documentar um surto de intoxicação espontânea por C. intermedium em bovinos leiteiros ocorrido na região Centro-Oriental do RS. Três bovinos com nove meses de idade, das raças Holandês e Jersey, foram acometidos depois de serem introduzidos em um pequeno piquete com escassez de forragem. Nessa área foram observados exemplares de Cestrum intermedium Sendtn com sinais de consumo. As taxas de morbidade e letalidade foram de 100% e os cursos clínicos variaram de 9 a 12 horas. Na necropsia dos três bovinos, observou-se predomínio de lesões hepáticas agudas. O fígado dos animais acometidos estava moderadamente aumentado de tamanho e na superfície de corte havia marcada acentuação do padrão lobular e hemorragia. Na abertura do rúmen, foram observadas folhas de Cestrum intermedium Sendtn parcialmente digeridas. Histologicamente, o fígado apresentava necrose coagulativa centrolobular e hemorragia. Frequentemente, essas alterações se estendiam para a região mediozonal. Foi realizada a técnica de imuno-histoquímica, na qual utilizou-se o anticorpo policlonal caspase 3 em fragmentos de fígado. Notou-se marcação moderada a acentuada em citoplasma e núcleo de hepatócitos, predominantemente na periferia das áreas de necrose hepática indicando apoptose celular. O diagnóstico de intoxicação por Cestrum intermedium Sendtn nos bovinos leiteiros desse estudo, foi realizado com base nos achados epidemiológicos, clínicos e anatomopatológicos. A intoxicação por C. intermedium é incomum em bovinos leiteiros, sendo descrita pela primeira vez na região centro oriental do RS e representa um diagnóstico diferencial de outras hepatopatias tóxicas agudas.(AU)

Upregulation of interferon-alpha gene in bovine embryos produced in vitro in response to experimental infection with noncytophatic bovine-viral-diarrhea virus.

In-vitro fertilization is a routine livestock-breeding technique widely used around the world. Several studies have reported the interaction of bovine viral-diarrhea virus (BVDV) with gametes and in-vitro-produced (IVP) bovine embryos. Since, gene expression in BVDV-infected IVP bovine embryos is scarcely addressed. The aim of this work was to evaluate the differential expression of genes involved in immune and inflammatory response. Groups of 20-25 embryos on Day 6 (morula stage) were exposed (infected) or not (control) to an NCP-BVDV strain in SOF medium. After 24 h, embryos that reached expanded blastocyst stage were washed. Total RNA of each embryo group was extracted to determine the transcription levels of 9 specific transcripts related with antiviral and inflammatory response by SYBR Green real time quantitative (RT-qPCR). Culture media and an aliquot of the last embryos wash on Day 7 were analyzed by titration and virus isolation, respectively. A conventional PCR confirmed BVDV presence in IVP embryos. A significantly higher expression of interferon-α was observed in blastocysts exposed to NCP-BVDV compared to the controls (p < 0.05). In this study, the upregulation of INFα and TLR7 genes involved in inflammatory and immune response in BVDV-infected IVP bovine embryos is a new finding in this field. This differential expression suggest that embryonic cells could function in a manner like immune cells by recognizing and responding early to interaction with viral pathogens. These results provide new insights into the action of BVDV on the complex molecular pathways controlling bovine early embryonic development.

Intramammary inoculation with lactic acid bacteria at dry-off triggers an immunomodulatory response in dairy cows.

The use of antibiotics to prevent bovine mastitis is responsible for the emergence and selection of resistant strains. Lactic acid bacteria (LAB) could be introduced into animal feed as an alternative prevention method that would bypass the risk of resistance development. In previous research, we demonstrated that two probiotic LAB strains isolated from bovine milk were capable of stimulating the production of antibodies and the host's immune cellular response in the udder. The present study aimed to elucidate whether the antibodies of animals inoculated with these strains were able to increase phagocytosis by neutrophils and inhibit the growth of different mastitis-causing pathogens. Moreover, the effect of LAB on the expression of pro-inflammatory cytokines was assessed. Ten animals were inoculated intramammarily with 106 cells of the two strains at dry-off. The blood serum was tested for its ability to opsonize bovine mastitis pathogens, the in vitro bactericidal activity of bovine blood and milk against these pathogens was determined, and cytokine mRNA expression was quantified in milk somatic cells. The inoculated animals did not show abnormal signs of sensitivity to the LAB. Their blood serum significantly enhanced the phagocytosis of Staphylococcus spp. and the LAB. Escherichia coli and Streptococcus uberis were inhibited by the milk serum but not the blood serum, whereas Staphylococcus aureus and Staphylococcus haemolyticus were inhibited by both. In regard to cytokine expression, interleukin (IL)-1ß increased markedly for up to 4 h post-inoculation, and an increase in IL-8 was observed 4, 12 and 24 h after inoculation. Tumour necrosis factor-α mRNA increased 1 and 2 h after inoculation and a significant difference was registered at 6 h for interferon-γ. This rapid immunomodulatory response shows that inoculating animals with LAB at dry-off, when they are especially susceptible, could be a useful strategy for the prevention of bovine mastitis.

A transcriptome and proteome of the tick Rhipicephalus microplus shaped by the genetic composition of its hosts and developmental stage.

The cattle tick, Rhipicephalus microplus, is a monoxenous tick that co-evolved with indicine cattle on the Indian subcontinent. It causes massive damage to livestock worldwide. Cattle breeds present heritable, contrasting phenotypes of tick loads, taurine breeds carrying higher loads of the parasite than indicine breeds. Thus, a useful model is available to analyze mechanisms that determine outcomes of parasitism. We sought to gain insights on these mechanisms and used RNA sequencing and Multidimensional Protein Identification Technology (MudPIT) to generate a transcriptome from whole larvae and salivary glands from nymphs, males and females feeding on genetically susceptible and resistant bovine hosts and their corresponding proteomes. 931,698 reads were annotated into 11,676 coding sequences (CDS), which were manually curated into 116 different protein families. Male ticks presented the most diverse armamentarium of mediators of parasitism. In addition, levels of expression of many genes encoding mediators of parasitism were significantly associated with the level and stage of host immunity and/or were temporally restricted to developmental stages of the tick. These insights should assist in developing novel, sustainable technologies for tick control.

Influence of an immune-modulatory feed supplement on performance and immune function of beef cows and calves preweaning.

The ability to positively alter immune and stress response with nutritional compounds is of great interest and importance to the beef industry. There is a proprietary product (OmniGen-AF [OG]; Phibro Animal Health, Quincy, IL) reported to have performance-enhancing benefits by altering animal response to stress and immune challenges. The objective of this 2-yr research project was to study the effect of supplementing OG to beef cows and their calves on breeding and growth performance. One hundred and twelve multiparous beef cows and 48 primiparous cows were randomly assigned to treatment in year 1; control (CON, no OG; n = 56 multiparous and 24 primiparous) or treatment (OG fed at 8.8 g/100 kg body weight [BW]; n = 56 multiparous and 24 primiparous). Multiparous cows (mean ± SD = 6.4 ± 0.4 yr; BW = 589 ± 9.2 kg; body condition score [BCS] 6.2 ± 0.07) were used in both years of the experiment and primiparous cows (mean ± SD = 2.1 ± 0.04 yr of age, weighed 400 ± 7.5 kg, and BSC of 5.6 ± 0.06) were only used in the first year of the experiment. CON and OG supplements were offered over two production cycles beginning in December approximately 60 d prior to projected calving through pre-breeding in May of each year. Calves from treatment cows were offered treatments in a creep supplement limited to a daily rate of 1% as-fed of BW prorated for 3-d/wk feeding from mid-July through weaning with OG offered at 8.8 g/100 kg BW. Primiparous cow's BW, BCS, and calf performance were not affected by treatment (P ≥ 0.15) in year 1. BW of multiparous OG cows tended (P = 0.10) to be heavier at weaning in year 1 and was greater (P = 0.05) at the onset of the experiment in year 2. Body condition of OG cows was greater (P ≤ 0.02) at weaning in both years 1 and 2, as well as at the onset of the experiment in year 2. Calves fed OG from the mature cows gained more (P = 0.05) BW during the creep feeding period than CON. Core body temperatures of OG heifers measured during the late summer with intravaginal temperature data loggers tended (P ≤ 0.10) to be less at 1400 and 1700 hours and were less (P = 0.05) at 1800 hours than CON heifers. Feeding OG did not result in changes (P = 0.25) in serum titer response to the BVD virus of calves during year 2. The results of the current experiment indicate feeding OG to beef cows and calves can result in improvement in BCS of cows, enhance weight gain of calves preweaning, and reduce heat loads in heifer calves during the late summer.

RNA Viruses of Amblyomma variegatum and Rhipicephalus microplus and Cattle Susceptibility in the French Antilles.

Ticks transmit a wide variety of pathogens including bacteria, parasites and viruses. Over the last decade, numerous novel viruses have been described in arthropods, including ticks, and their characterization has provided new insights into RNA virus diversity and evolution. However, little is known about their ability to infect vertebrates. As very few studies have described the diversity of viruses present in ticks from the Caribbean, we implemented an RNA-sequencing approach on Amblyomma variegatum and Rhipicephalus microplus ticks collected from cattle in Guadeloupe and Martinique. Among the viral communities infecting Caribbean ticks, we selected four viruses belonging to the Chuviridae, Phenuiviridae and Flaviviridae families for further characterization and designing antibody screening tests. While viral prevalence in individual tick samples revealed high infection rates, suggesting a high level of exposure of Caribbean cattle to these viruses, no seropositive animals were detected. These results suggest that the Chuviridae- and Phenuiviridae-related viruses identified in the present study are more likely tick endosymbionts, raising the question of the epidemiological significance of their occurrence in ticks, especially regarding their possible impact on tick biology and vector capacity. The characterization of these viruses might open the door to new ways of preventing and controlling tick-borne diseases.

Analysis of the efficiency of active immunization against IBR, BVD and leptospirosis in increasing pregnancy rate in FTAI protocols / Análise da eficiência da imunização ativa contra IBR, BVD e Leptospirose para elevar a taxa de prenhezem protocolos de IATF

Beef cattle farming is a highly representative activity for the GDP of Brazil, rendering the country an important producer of beef. For Brazil to maintain this prominent position, sanitary management actions must be carried out, such as the control of reproductive diseases. This study examines the effectiveness of vaccination against reproductive diseases in bovine females. Data from 8752 Zebu cows on the status of vaccination against reproductive diseases, body condition score (BCS) and the subsequent result of pregnancy diagnosis were evaluated. With regard to BCS, primiparous was the category that most demonstrated the effect of body condition on pregnancy rate, with BCS 3.5 cows having a 30% higher rate than the animals with BCS 2. In the group of nulliparous cows, those with BCS 3.5 had a pregnancy rate of 58% vs. 46% in BCS 3 cows. The induced nulliparae with BCS 3.5 had a 9% higher pregnancy rate than those with BCS 3. Multiparous cows also had a 9% higher rate when their BCS was 3.5 as compared with BCS 2. Among the evaluated dams, 46.5% were vaccinated against IBR, BVD and leptospirosis. Of these, the primiparae showed a 21% increase in conception as compared with the non-vaccinated group; multiparae, 10%; nulliparae, 5.9%; and induced nulliparae, 7.8%. In conclusion, BCS directly influences the reproductive efficiency of bovine females, and the use of vaccination

A bovinocultura de corte é muito representativa para o PIB brasileiro, tornando o país um importante produtor de carne bovina. Para manter este patamar ações de manejo sanitário devem ser executadas, dentre elas o controle de doenças reprodutivas. O presente trabalho teve por objetivo avaliar a eficácia do uso de vacinas contra doenças reprodutivas em fêmeas bovinas. Para isso foram avaliados dados de 8752 fêmeas bovinas zebuínas. Os dados analisados foram referentes à condição vacinal contra doenças reprodutivas, escore de condição corporal (ECC) e posterior resultado do diagnóstico de gestação. Com relação ao ECC, primípara foi a categoria que mais demonstrou o efeito do ECC na taxa de prenhez, com ECC 3,5 apresentou índice 30% superior a animais com ECC 2. Nulíparas apresentaram 58% com ECC 3,5 em comparação ao ECC 3, 46%, assim como as nulíparas induzidas, que com ECC 3,5 apresentaram taxa de prenhez 9% superior as com ECC 3. As multíparas também apresentaram 9% a mais de prenhez quando possuíam ECC 3,5 em comparação ao ECC 2. Dentre as matrizes avaliadas, 46,5% foram vacinadas contra IBR, BVD e leptospirose. Destas, as primíparas, apresentaram 21% de aumento na concepção nas vacinadas, assim como as multíparas que apresentaram 10%, nulíparas 5,9% e nulíparas induzidas 7,8%. Assim concluiu-se que o ECC influencia diretamente na eficiência reprodutiva das fêmeas bovinas e que o uso de vacina contra doenças reprodutivas pode ser indicado, porém esta indicação deve ser baseada em dados epidemiológicos e zootécnicos de cada propriedade.

Analysis of the efficiency of active immunization against IBR, BVD and leptospirosis in increasing pregnancy rate in FTAI protocols / Análise da eficiência da imunização ativa contra IBR, BVD e Leptospirose para elevar a taxa de prenhezem protocolos de IATF

Beef cattle farming is a highly representative activity for the GDP of Brazil, rendering the country an important producer of beef. For Brazil to maintain this prominent position, sanitary management actions must be carried out, such as the control of reproductive diseases. This study examines the effectiveness of vaccination against reproductive diseases in bovine females. Data from 8752 Zebu cows on the status of vaccination against reproductive diseases, body condition score (BCS) and the subsequent result of pregnancy diagnosis were evaluated. With regard to BCS, primiparous was the category that most demonstrated the effect of body condition on pregnancy rate, with BCS 3.5 cows having a 30% higher rate than the animals with BCS 2. In the group of nulliparous cows, those with BCS 3.5 had a pregnancy rate of 58% vs. 46% in BCS 3 cows. The induced nulliparae with BCS 3.5 had a 9% higher pregnancy rate than those with BCS 3. Multiparous cows also had a 9% higher rate when their BCS was 3.5 as compared with BCS 2. Among the evaluated dams, 46.5% were vaccinated against IBR, BVD and leptospirosis. Of these, the primiparae showed a 21% increase in conception as compared with the non-vaccinated group; multiparae, 10%; nulliparae, 5.9%; and induced nulliparae, 7.8%. In conclusion, BCS directly influences the reproductive efficiency of bovine females, and the use of vaccination

A bovinocultura de corte é muito representativa para o PIB brasileiro, tornando o país um importante produtor de carne bovina. Para manter este patamar ações de manejo sanitário devem ser executadas, dentre elas o controle de doenças reprodutivas. O presente trabalho teve por objetivo avaliar a eficácia do uso de vacinas contra doenças reprodutivas em fêmeas bovinas. Para isso foram avaliados dados de 8752 fêmeas bovinas zebuínas. Os dados analisados foram referentes à condição vacinal contra doenças reprodutivas, escore de condição corporal (ECC) e posterior resultado do diagnóstico de gestação. Com relação ao ECC, primípara foi a categoria que mais demonstrou o efeito do ECC na taxa de prenhez, com ECC 3,5 apresentou índice 30% superior a animais com ECC 2. Nulíparas apresentaram 58% com ECC 3,5 em comparação ao ECC 3, 46%, assim como as nulíparas induzidas, que com ECC 3,5 apresentaram taxa de prenhez 9% superior as com ECC 3. As multíparas também apresentaram 9% a mais de prenhez quando possuíam ECC 3,5 em comparação ao ECC 2. Dentre as matrizes avaliadas, 46,5% foram vacinadas contra IBR, BVD e leptospirose. Destas, as primíparas, apresentaram 21% de aumento na concepção nas vacinadas, assim como as multíparas que apresentaram 10%, nulíparas 5,9% e nulíparas induzidas 7,8%. Assim concluiu-se que o ECC influencia diretamente na eficiência reprodutiva das fêmeas bovinas e que o uso de vacina contra doenças reprodutivas pode ser indicado, porém esta indicação deve ser baseada em dados epidemiológicos e zootécnicos de cada propriedade.(AU)

Nutraceutical effect of vitamins and minerals on performance and immune and antioxidant systems in dairy calves during the nutritional transition period in summer.

We aimed to determine whether the use of injectable vitamins and minerals improves growth performance and immune and antioxidant responses in dairy calves during pre- and post-weaning period in summer. Twenty dairy calves (45 days of age) were randomized to two groups (10 each): control group (CON) and treated group [TREAT; injection providing 0.20, 0.80, 0.20, 0.10, 35 and 1 mg/kg of copper, zinc, manganese selenium, and vitamins A and E, during two periods (15 days pre- and 15 days post-weaning)]. The animals were weighed and blood samples were collected on days 1, 15, 30 and 45 of the study. Levels of serum copper, selenium, zinc, and manganese were measured on day 1; and the results showed that calves were not deficient in these minerals. The TREAT group had greater BW gain during the final third of the experiment. There was an increase in total leukocyte numbers as a result of elevation in neutrophil counts (day 45) and monocytes (days 30 and 45) in the TREAT group. This group also had lower reactive oxygen species (ROS) content (days 15, 30 and 45) and lipid peroxidation (LPO; days 15 and 45). Furthermore, the TREAT group had greater antioxidant capacity against peroxyl radicals (ACAP; days 15 and 30), activities of the enzymes glutathione peroxidase (GPx; days 15, 30 and 45) and superoxide dismutase (SOD; day 15), concentrations of total serum proteins (day 30), serum globulin (days 15 and 30), ceruloplasmin (day 15), tumor necrosis factor-alpha (TNF-α), interleukin-1, (IL-1; days 30 and 45) and interferon gamma (IFNγ; day 45), compared to CON group. High respiratory rates during hot times of the day in all study calves was suggestive of heat stress. Taken together, the data suggest that mineral and vitamins injections increased the growth performance and boosted the antioxidant and immunological systems of dairy calves during the diet transition period in summer.

Serum biochemical profile of neonatal buffalo calves / Perfil bioquímico sérico de bezerros bubalinos no período neonatal

Serum blood samples from 50 Murrah buffalo calves were examined in this study. The animals were allocated into three groups according to the number of parturitions of their mothers: G1 (n= 15) calves from primiparous buffaloes, G2 (n= 19) calves from buffaloes with two to four parturitions, and G3 (n= 16) calves from buffaloes with five or more parturitions. Blood samples were taken at birth, before colostrum ingestion, at 24h, 48h, and 72h after birth, and at 7, 14, 21, and 30 days after birth for determination of levels of gammaglutamyl transferase (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), creatine kinase, total protein, albumin, globulins (including immunoglobulin G), iron, total calcium, ionized calcium, phosphorus, sodium, and potassium. The age of the calves was found to influence all of the biochemical parameters, with the exception of ionized calcium and potassium in the calves in groups G1 and G3. The calving order was found to influence AST, GGT, total protein, albumin, and globulins, including IgG. The high serum ALP activity in the first two days after birth indicates that measurement of the levels of this enzyme may be used as an indirect method of assessing passive immunity transfer.(AU)

Amostras de sangue de 50 bezerros de búfalo Murrah foram examinados nesse estudo. Os animais foram distribuídos em três grupos de acordo com a paridade de suas genitoras: G1 (n=15) bezerros de búfalas primíparas, G2 (n=19) bezerros de búfalas com 2 a 4 gestações, e G3 (n=16) bezerros de búfalas com cinco ou mais gestações. Amostras de sangue foram colhidas ao nascimento, antes da ingestão de colostro e 24h, 48h, e 72h após o nascimento e 7, 14, 21 e 30 dias após nascimento para determinar níveis de gammaglutamil transferase (GGT), fosfatase alcalina (ALP), aspartato aminotrasferase (AST), creatina quinase, proteínas totais, albumina, globulina (inclusive imunoglobulina G), ferro, cálcio total, cálcio ionizado, fósforo, sódio e potássio. A idade dos bezerros influenciou todos os parâmetros bioquímicos, exceto cálcio ionizado e potássio nos bezerros dos grupos G1 e G3. A ordem de nascimento influenciou AST, GGT, proteínas totais, albumina e globulinas, inclusive IgG. Intensa atividade ALP no soro nos primeiros dois dias após nascimento indica que medidas dos níveis dessa enzima podem ser utilizados como método indireto de avaliar transferência passiva de imunidade.(AU)

Serum biochemical profile of neonatal buffalo calves / Perfil bioquímico sérico de bezerros bubalinos no período neonatal

Serum blood samples from 50 Murrah buffalo calves were examined in this study. The animals were allocated into three groups according to the number of parturitions of their mothers: G1 (n= 15) calves from primiparous buffaloes, G2 (n= 19) calves from buffaloes with two to four parturitions, and G3 (n= 16) calves from buffaloes with five or more parturitions. Blood samples were taken at birth, before colostrum ingestion, at 24h, 48h, and 72h after birth, and at 7, 14, 21, and 30 days after birth for determination of levels of gammaglutamyl transferase (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), creatine kinase, total protein, albumin, globulins (including immunoglobulin G), iron, total calcium, ionized calcium, phosphorus, sodium, and potassium. The age of the calves was found to influence all of the biochemical parameters, with the exception of ionized calcium and potassium in the calves in groups G1 and G3. The calving order was found to influence AST, GGT, total protein, albumin, and globulins, including IgG. The high serum ALP activity in the first two days after birth indicates that measurement of the levels of this enzyme may be used as an indirect method of assessing passive immunity transfer.(AU)

Amostras de sangue de 50 bezerros de búfalo Murrah foram examinados nesse estudo. Os animais foram distribuídos em três grupos de acordo com a paridade de suas genitoras: G1 (n=15) bezerros de búfalas primíparas, G2 (n=19) bezerros de búfalas com 2 a 4 gestações, e G3 (n=16) bezerros de búfalas com cinco ou mais gestações. Amostras de sangue foram colhidas ao nascimento, antes da ingestão de colostro e 24h, 48h, e 72h após o nascimento e 7, 14, 21 e 30 dias após nascimento para determinar níveis de gammaglutamil transferase (GGT), fosfatase alcalina (ALP), aspartato aminotrasferase (AST), creatina quinase, proteínas totais, albumina, globulina (inclusive imunoglobulina G), ferro, cálcio total, cálcio ionizado, fósforo, sódio e potássio. A idade dos bezerros influenciou todos os parâmetros bioquímicos, exceto cálcio ionizado e potássio nos bezerros dos grupos G1 e G3. A ordem de nascimento influenciou AST, GGT, proteínas totais, albumina e globulinas, inclusive IgG. Intensa atividade ALP no soro nos primeiros dois dias após nascimento indica que medidas dos níveis dessa enzima podem ser utilizados como método indireto de avaliar transferência passiva de imunidade.(AU)

Delayed type hypersensitivity induced by intradermal inoculation of a Neospora caninum tachyzoite antigen in previously exposed cattle.

The aim of this study was to evaluate delayed type hypersensitivity (DTH) induced by the intradermal inoculation of a Neospora caninum tachyzoite soluble lysate in cattle previously exposed with the protozoa. Four experimental groups were selected according to the prior exposure to N. caninum antigen. All cows were intradermally injected with a N. caninum tachyzoite soluble lysate and skinfold thickness growth at the inoculation sites was measured at 0, 24, 48, 72 and 96 h post inoculation (hpi). Additionally, specific antibodies and IFN-γ production were assessed. Cows experimentally infected with live N. caninum tachyzoites and cows naturally exposed to N. caninum developed skin reactions compatible with DTH between 24 and 96 hpi (p < 0.05). Moreover, cows inoculated with an experimental N. caninum vaccine and cows without evidence of exposure to N. caninum did not show a significant increase in skin thickness (p > 0.05). Furthermore, serological status of the animals was not modified due to the intradermal inoculation. The highest IFN-γ production was observed at 15 days after intradermal inoculation (p < 0.05). Therefore, these results suggest that cattle previously exposed to N. caninum develop a reaction compatible with DTH which could be useful as in vivo cell mediated immunity parameter for assessed bovine neosporosis.

Meningoencephalitis due to Naegleria fowleri in cattle in southern Brazil / Meningoencefalite por Naegleria fowleri em um bovino no sul do Brasil

Naegleria fowleri is a free-living amoeba commonly found in the environment, mainly in fresh water and soil. This protozoon is occasionally involved in cases of fatal central nervous system disease in humans and other animal species. We describe here a case of meningoencephalitis due to Naegleria fowleri in cattle, in southern Brazil. A four-year-old Angus cow presented a clinical history of initial mild neurological signs that progressed to paddling movements, opisthotonus and lateral recumbency after five days. This animal had been kept in an irrigated rice stubble paddock. Grossly, the main lesions consisted of multiple areas of malacia in the right olfactory bulb, piriform lobes, hippocampus, frontal lobe cortex and fornix, along with severe thickening of the mesencephalon and rhombencephalon leptomeninges. Microscopically, severe multifocal necrosuppurative and hemorrhagic meningoencephalitis associated with a large quantity of amoebic trophozoites was present. The latter were confirmed to be Naegleria spp., through immunohistochemistry. Based on the strong congruence with the histopathological data of known cases reported in the literature, a probable association with Naegleria fowleri was established. To our knowledge, this is only the second report of Naegleria fowleri-associated meningoencephalitis in cattle in South America, and it is the first in southern Brazil.(AU)

Naegleria fowleri é uma ameba de vida livre, comumente encontrada no meio ambiente, principalmente em água doce e no solo. Este protozoário é ocasionalmente associado a casos fatais de doença do sistema nervoso central em seres humanos e espécies animais. No presente trabalho, um caso de meningoencefalite por Naegleria fowleri em um bovino na região sul do Brasil é descrito. Uma vaca Angus, de quatro anos de idade apresentou histórico clínico caracterizado inicialmente por sinais neurológicos leves que progrediram para movimentos de pedalagem, opistótono e decúbito lateral após cinco dias. Este animal era mantido em um piquete em resteva de arroz irrigado. Macroscopicamente, as principais lesões foram caracterizadas por múltiplas áreas de malacia no bulbo olfatório direito, lobos piriformes, hipocampo, córtex do lobo frontal e no fórnix, bem como acentuado espessamento das leptomeninges do mesencéfalo e rombencéfalo. Microscopicamente, meningoencefalite necrossupurativa e hemorrágica associada à grande número de trofozoítos amebianos foram observadas. Estes foram confirmados como Naegleria spp. através de imuno-histoquímica. Baseado na forte congruência apresentada entre os dados histopatológicos provenientes de casos conhecidos publicados na literatura, uma provável associação com Naegleria fowleri foi estabelecida. O presente trabalho trata-se do segundo relato de meningoencefalite associada à Naegleria fowleri em bovinos na América do Sul e o primeiro na região sul do Brasil.(AU)