PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Baptista A.A.S., Donato T.C., Souza, E.E., Gonçalves G.A.M., Garcia, K.C.O.D., Rodrigues J.C.Z., Sequeira J.L. & Andreatti Filho R.L. 2013. Induction of immune response in broiler chickens immunized with recombinant FliC and challenged by Salmonella Typhimurium. Pesquisa Veterinária Brasileira 33(10):1215-1221. Departamento de Clínica Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista Júlio de Mesquita Filho, Unesp-Botucatu, Distrito de Rubião Júnior s/n, Botucatu, SP 18608-970, Brazil. E-mail: angelita_sampaio@yahoo.com.br The study examined (1) the immune response in broiler chickens after oral immunization with recombinant flagellin (rFliC) from Salmonella Typhimurium conjugated with sodium alginate microparticles, and the immune response enhancement in association with recombinant cholera toxin B subunit protein (rCTB) and pool of Lactobacillus spp. (PL). The immune responses were evaluated by dosage of IgY serum and IgA from intestinal fluid and immunostaining of CD8+ T lymphocytes in the cecum. The immunized animals were challenged with Salmonella Typhimurium (ST) 21 days after treatment. In all immunized groups, a significant increase (p<0.05) was observed in IgA levels (mg/mL), especially three weeks after immunization. The serum IgY levels (mg/mL) were little affected by the treatments and differed significantly among groups only in the second post-immunization week (p<0.05). After the challenge, the number of CD8+ T cells differed significantly between the treatments and negative control. Retrieval of Salmonella Typhimurium was not detected at 48 hours after the challenge in T2 (rFliC+rCTb), T3 (rFliC+PL) and T4 (rFliC+rCTB PL). The rFliC administered orally with or without rCTB and Lactobacillus spp. produces significant induction of humoral immune response, and the immunized chickens were more effective in eliminating Salmonella after challenge.

• Salmonella Typhimurium FliC

Abstract in Portuguese:

RESUMO.- Baptista A.A.S., Donato T.C., Souza, E.E., Gonçalves G.A.M., Garcia, K.C.O.D., Rodrigues J.C.Z., Sequeira J.L. & Andreatti Filho R.L. 2013. Induction of immune response in broiler chickens immunized with recombinant FliC and challenged by Salmonella Typhimurium. [Indução de resposta imune em frangos de corte imunizados com FliC recombinante e desafiados por Salmonella Typhimurium.] Pesquisa Veterinária Brasileira 33(10):1215-1221. Departamento de Clínica Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista Júlio de Mesquita Filho, Unesp-Botucatu, Distrito de Rubião Júnior s/n, Botucatu, SP 18608-970, Brazil. E-mail: angelita_sampaio@yahoo.com.br Este estudo investigou a resposta imunitária de frangos de corte após a imunização oral com flagelina recombinante (rFliC) de Salmonella Typhimurium conjugada com micropartículas de alginato de sódio, e como intensificador de resposta imune foi associada a proteína subunidade B da toxina colérica (rCTB) e pool de Lactobacillus spp. (PL). As respostas imunes foram avaliadas por dosagem de IgY sérica e IgA do fluído intestinal e imunomarcação de linfócitos T CD8+ presentes no ceco. Os animais imunizados foram desafiados aos 21 dias após tratamento com Salmonella Typhimurium (ST). Foi observado em todos os grupos imunizados um aumento significativo (p<0,05) nos níveis de IgA (mg/mL) principalmente três semanas após as imunizações. Os níveis de IgY sérica (mg/mL) foram pouco influenciados pelos tratamentos, apenas na segunda semana após imunização observou-se diferenças significativas (p<0,05) entre os grupos. Observou-se que o número de linfócitos T CD8+ apresentou diferença significativa entre os tratamentos e o controle negativo após o desafio. Quanto a recuperação de Salmonella Typhimurium, observou-se que 48 horas após o desafio já não havia detecção do agente nos grupos T2 (rFliC+rCTb), T3 (rFliC+PL) e T4 (rFliC+rCTB+PL). Concluí-se que rFliC administrada, via oral, associada ou não a Lactobacillus spp e rCTB, demonstrou induzir significativamente a resposta imune humoral e que as aves imunizadas foram mais eficientes na eliminação de Salmonella após desafio.

Abstract in English:

ABSTRACT.- Fernandes W.R., Rodrigues J.A., Michima L.E.S. & Siqueira R.F. 2012. [Oxidative stress evaluation in Standardbred horses through malondialdehyde (MDA) and erythrocytic reduced glutathione (GSH) mensuration.] Avaliação do estresse oxidativo em cavalos de trote através da mensuração de malondialdeído (MDA) e glutationa reduzida (GSH) eritrocitária. Pesquisa Veterinária Brasileira 32(7):677-680. Departamento de Clínica Médica, Faculdade de Medicina Veterinária, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Bloco 15, Cidade Universitária, São Paulo, SP 05508-270, Brazil. E-mail: refarinelli@yahoo.com.br Oxidative stress by physical exercise induces a lipidic peroxidation reaction in cellular membranes and damages in proteins and nucleic acids. Malondialdehyde (MDA) is one of the final products of this reaction. Erythrocytic reduced glutathione (GSH), a multifunctional antioxidant, is present in the plasma and erythrocyts and it represents the total antioxidant suitability of the organism after an oxidative stress. The aim of this study was to evaluate the oxidative stress in different physical exercise conditions through serum MDA and erythrocytic GSH measurement in 45 American Trotter and crossbred horses distributed in three groups: G1 (no physical exercise), G2 (until 6 months of regular physical exercise) and G3 (more than 12 months of regular physical exercise). In the animals with no physical exercise MDA values were lower than the others. There was no difference in GSH values corrected by hemoglobin (Hb) or hematocrit (VG) values among the groups. However, there was a tendency of greater values in G2, where their antioxidant system is adapting to the regular physical exercises and their consequent damages. We conclude that physical exercises induce cellular damage by oxidative stress, but the antioxidant system keeps the homeostasy and it is capable to adapt itself to the free radicals harm.

• Oxidative stress malondialdehyde glutathione estresse oxidativo malondialdeído glutationa

Abstract in Portuguese:

RESUMO.- Fernandes W.R., Rodrigues J.A., Michima L.E.S. & Siqueira R.F. 2012. [Oxidative stress evaluation in Standardbred horses through malondialdehyde (MDA) and erythrocytic reduced glutathione (GSH) mensuration.] Avaliação do estresse oxidativo em cavalos de trote através da mensuração de malondialdeído (MDA) e glutationa reduzida (GSH) eritrocitária. Pesquisa Veterinária Brasileira 32(7):677-680. Departamento de Clínica Médica, Faculdade de Medicina Veterinária, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Bloco 15, Cidade Universitária, São Paulo, SP 05508-270, Brazil. E-mail: refarinelli@yahoo.com.br O estresse oxidativo, decorrente de uma atividade física, leva a peroxidação lipídica de membranas celulares, além de danos protéicos e em ácidos nucléicos, e um dos produtos finais desta reação é o malondialdeído (MDA). A glutationa reduzida (GSH), considerada um antioxidante multifuncional, está presente no plasma e principalmente nas hemácias e tem importância pelo fato de ser um dos índices da capacidade total antioxidante do corpo após um estresse oxidativo. Com o objetivo de avaliar o estresse oxidativo em diferentes condições de treinamento físico, determinaram-se a concentração de MDA sérico e GSH eritrocitária em 45 cavalos da raça American Trotter e mestiços divididos em três grupos: G1 (sem treinamento), G2 (até 6 meses de treinamento) e G3 (treinamento há mais de 12 meses). Observou-se que o MDA teve um valor significativamente menor no grupo de animais sem treinamento físico. Não houve diferença estatística significante para GSH corrigida pela Hb e para GSH corrigida pelo VG entre os grupos analisados, mas houve uma aparente tendência a maiores valores no G2, no qual o sistema antioxidante está em fase de adaptação ao treinamento físico constante e suas consequentes injúrias. Conclui-se que a atividade física acarreta danos celulares frente ao estresse oxidativo, mas o sistema antioxidante tem papel fundamental nesta homeostasia observando uma adaptação às injúrias causadas pelos radicais livres.

Abstract in English:

ABSTRACT.- Coelho A.C., Pinto M.L., Coelho A.M. & Rodrigues J. 2009. [Comparison of two techniques of isolation of Mycobacterium avium subsp. paratuberculosis in faecal samples of ovine with clinical suspicion of paratuberculosis.] Comparação de duas técnicas de isolamento de Mycobacterium avium subsp. paratuberculosis em amostras de fezes de ovinos com suspeita clínica de paratuberculose. Pesquisa Veterinária Brasileira 29(5):415-420. Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal. E-mail: accoelho@utad.pt Paratuberculosis is a chronic enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis. Culture of bacteria from faeces and tissues samples constitutes one of the most effective methods of confirming the diagnosis of para-tuberculosis and the only method available to obtain strains of mycobacteria. However, this method is less sensitive and requires months of incubation before colony growth occurs. In this study, culture method was used on sheep faeces to diagnose paratuber-culosis in animals with compatible signs of the disease. A comparison of two culture media used to isolation was also investigated. Culture was positive in 2.0% of faecal samples. Isolation was obtained using Löwenstein Jensen® with mycobactin® J, and the Middlebrook® 7H11 with OADC®. The Löwenstein Jensen® with mycobactin® J was that provided highest amount of isolations. The percentages of isolation in each culture media were 2.0% (6/300) to Löwenstein Jensen® with micobactina J, and 1.0% (3/300) to Middlebrook® 7H11/OADC. The three positive samples in Middlebrook® 7H11/OADC were also positive in Löwenstein Jensen® with micobactina J. In the Middlebrook® 7H11/OADC alone there was no sample growth. The results of this study suggest that culture media of Löwenstein-Jensen® with micobactina® J is more effective for the isolation of sheep strains in Portugal.

• Paratuberculosis Mycobacterium avium subsp. paratuberculosis paratuberculose

Abstract in Portuguese:

ABSTRACT.- Coelho A.C., Pinto M.L., Coelho A.M. & Rodrigues J. 2009. [Comparison of two techniques of isolation of Mycobacterium avium subsp. paratuberculosis in faecal samples of ovine with clinical suspicion of paratuberculosis.] Comparação de duas técnicas de isolamento de Mycobacterium avium subsp. paratuberculosis em amostras de fezes de ovinos com suspeita clínica de paratuberculose. Pesquisa Veterinária Brasileira 29(5):415-420. Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal. E-mail: accoelho@utad.pt Paratuberculosis is a chronic enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis. Culture of bacteria from faeces and tissues samples constitutes one of the most effective methods of confirming the diagnosis of para-tuberculosis and the only method available to obtain strains of mycobacteria. However, this method is less sensitive and requires months of incubation before colony growth occurs. In this study, culture method was used on sheep faeces to diagnose paratuber-culosis in animals with compatible signs of the disease. A comparison of two culture media used to isolation was also investigated. Culture was positive in 2.0% of faecal samples. Isolation was obtained using Löwenstein Jensen® with mycobactin® J, and the Middlebrook® 7H11 with OADC®. The Löwenstein Jensen® with mycobactin® J was that provided highest amount of isolations. The percentages of isolation in each culture media were 2.0% (6/300) to Löwenstein Jensen® with micobactina J, and 1.0% (3/300) to Middlebrook® 7H11/OADC. The three positive samples in Middlebrook® 7H11/OADC were also positive in Löwenstein Jensen® with micobactina J. In the Middlebrook® 7H11/OADC alone there was no sample growth. The results of this study suggest that culture media of Löwenstein-Jensen® with micobactina® J is more effective for the isolation of sheep strains in Portugal.

Abstract in English:

ABSTRACT.- Rodrigues J., Meireles G.S., Carvalho Filho P.R., Ribeiro C.T., Flausino W. & Lopes C.W.G. 2008. [Sarcocystis cruzi (Apicomplexa: Sarcocystidae) in the crab-eating fox (Cerdocyon thous).] Sarcocystis cruzi (Apicomplexa: Sarcocystidae) no cachorro-do-mato (Cerdocyon thous). Pesquisa Veterinária Brasileira 28(11):561-564. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: lopescwg@ufrrj.br Sporocysts of Sarcocystis were identified in feces samples of a crab-eating fox, and were orally given to a suckling calf; after 3 months of infection, sarcocysts morphologically similar to Sarcocystis cruzi were observed in cardiac and skeletal striated muscles. The cardiac muscles of this calf were orally given to a puppy free of coccidia, that shed sporocysts in its feces.with a prepatent and patent period of 11 and 12 days after infection, respectively. To compare the morphology of the sporocysts and cysts, a second puppy was fed on bovine cardiac muscles infected naturally, and sporocysts identical to those shed by the first dog were recovered from its feces. In spite of the significant difference between sporocysts found in the mucosa of the crab-eating fox and those shed by the first and second puppies, the species observed in this study was considered to be Sarcocystis cruzi, based on size of the sporocyts, morphology of the cyst wall, and the pray-predator cycle.

• Sarcocystis cruzi sporocysts cysts crab-eating fox Cerdocyon thous dogs cattle

Abstract in Portuguese:

ABSTRACT.- Rodrigues J., Meireles G.S., Carvalho Filho P.R., Ribeiro C.T., Flausino W. & Lopes C.W.G. 2008. [Sarcocystis cruzi (Apicomplexa: Sarcocystidae) in the crab-eating fox (Cerdocyon thous).] Sarcocystis cruzi (Apicomplexa: Sarcocystidae) no cachorro-do-mato (Cerdocyon thous). Pesquisa Veterinária Brasileira 28(11):561-564. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: lopescwg@ufrrj.br Sporocysts of Sarcocystis were identified in feces samples of a crab-eating fox, and were orally given to a suckling calf; after 3 months of infection, sarcocysts morphologically similar to Sarcocystis cruzi were observed in cardiac and skeletal striated muscles. The cardiac muscles of this calf were orally given to a puppy free of coccidia, that shed sporocysts in its feces.with a prepatent and patent period of 11 and 12 days after infection, respectively. To compare the morphology of the sporocysts and cysts, a second puppy was fed on bovine cardiac muscles infected naturally, and sporocysts identical to those shed by the first dog were recovered from its feces. In spite of the significant difference between sporocysts found in the mucosa of the crab-eating fox and those shed by the first and second puppies, the species observed in this study was considered to be Sarcocystis cruzi, based on size of the sporocyts, morphology of the cyst wall, and the pray-predator cycle.

Abstract in English:

Blood samples were obtained at slaughter from sixty 43 to 56 day old broilers, from each of 60 healthy flocks located in a region of high density poultry production. The flocks tested corresponded to approximately 10% of the total number existing in the region and were located within a radius of 50 km. All broilers had been vaccinated against Marek's disease atone day of age. Sera were tested in the immunodiffusion test for antibodies to avian reovirus (ARV), infectious bursal disease vírus (IBDV), fowl poxvirus (FPV), herpes virus of turkeys (HVT), avian adenovirus of groups 1 (AAV-1) and 2 (AAV-2). The sarne sera were tested in the micro serum neutralization test in plates for antibodies to infectious bronchitis virus (IBV) and infectious laryngotracheitis virus (ILTV), and for hemagglutination inhibition antibodies to Newcastle disease virus (NDV). Antibodies to ARV, detected in 2172 (63.6%) of 3418 sera, and to AAV-1, in 2701 (78.2%) of 3456 sera, were found in all 60 flocks, while antibodies to IBDV, in 3086 (89.4%) of 3452 sera, were found in only 57 of the sarne flocks. These results indicated that the three viruses are ubiquitous in broilers. Antibodies to FPV in 14 (0.5%) of 2935 sera, and to NDV in 6 (0.2%) of 3320 sera, were demonstrated in five of 59 and in one of 60 flocks, respectively, indicating that these two viruses occur only rarely. Antibodies to HVT, in 315 (9.0%) of 3384 sera, were detected in 39 of 60 flocks tested, suggesting poor serological response to vaccination and low field exposure to MDV. Antibodies to IBV, in 61 (2.1 %) of 2925 sera, were found in 12 of 57 flocks tested. However, in only one flock was the percentage of reactors significant (41 %); in the 11 flocks the percentage of broilers with antibody ranged from 1.7 to 16.1 %. Finally, no antibodies were found in 3491 sera from 60 flocks tested for AAV-2, nor in 3035 sera from 59 flocks when tested for ILTV, indicating that these two viruses do not exist in the geographical area tested. The significance of these findings is discussed.

• Antibodies broilers reovirus Gumboro Fowl pox Marek's disease adenoviruses infectious bronchitis infectious laryngotracheitis Newcastle disease

Abstract in Portuguese:

Amostras de sangue foram obtidas ao abate de 60 frangos de corte, de 43 a 56 dias de idade, de cada uma de 60 granjas sem problemas sanitários aparentes localizadas em uma região de alta densidade de produção avícola. As granjas correspondiam a 10% do número total que existe na região e estavam localizadas em um raio de 50 km. Todos os frangos tinham sido vacinados contra a doença de Marek no primeiro dia de vida. Os soros foram avaliados no teste de imunodifusão para anticorpos para reovírus aviário (R V A), vírus da doença infecciosa da bursa (VDIB), vírus da bouba aviária (VBA), vírus herpes de perus (HVT), adenovírus aviário do grupo 1 (AVA-1) e do grupo 2 (A VA-2). Os mesmos soros foram examinados no microteste de soroneutralização em placas para anticorpos para o vírus da bronquite infecciosa (VBI) e o vírus da laringotraqueíte infecciosa (VLTI), bem como anticorpos inibidores da hemoaglutinação para o vírus da doença de Newcastle (VDN). Anticorpos para RVA, detectados em 2172 (63,6%) de 3418 soros, e para AVA-1, em 2701 (78,2%) de 3456 soros, foram demonstrados em todas as 60 granjas, enquanto que, anticorpos para o VDIB, em 3086 (89,4%) de 3452 soros, foram encontrados em somente 57 destas granjas. Estes resultados indicam que os três vírus são ubíquos em frangos de corte da região estudada. Anticorpos para o VBA em 14 (0,5%) de 2935 soros, para o VDN em seis (0,2%) de 3320 soros, foram encontrados em cinco de 59 e em uma de 60 granjas, respectivamente, indicando que esses dois vírus ocorrem apenas raramente. Anticorpos para HVT, em 315 (9,0%) de 3484 soros, foram detectados em 39 de 60 granjas testadas, sugerindo resposta sorológica pobre à vacinação e baixa exposição de campo ao vírus da doença de Marek. Anticorpos para o VBI, em 61 (2,1%) de 2925 soros, foram encontrados em 12 de 57 granjas testadas. Porém, em apenas uma granja a percentagem de reagentes era significativa (41 %); nas outras 11 granjas a percentagem de frangos com anticorpos variava de 1,7 a 16,1%. Finalmente, não foram detectados anticorpos em 3491 soros de 60 granjas testada para A VA-2, nem em 3035 soros de 59 granjas testadas para o VLTI, indicando que esses vírus não existem na área geográficas estudada. O significado de todos os achados é discutido.

• Anticorpos frangos de corte reovírus Gumboro bouba Marek adenovírus bronquite infecciosa laringotraqueíte infecciosa Newcastle

Abstract in English:

From October through December, 1980, a study of embryo transfer in cattle was carried out in the State of Rio Grande do Sul, Brazil. Twenty-five cows were used as donors. The breeds involved were Hereford (10), Aberdeen Angus (4), Normand (6) and Charolais (5). Forty cows Hereford Aberdeen Angus, Normand, Charolais and Holstein crosses were used as recipients. Oestrus synchronization and superovulation were obtained using prostaglandins alpha analogue and PMSG. Fourteen (56%) of the donors responded well to the superovulation treatment with PMSG, producing an average of 6.2 corpora lutea per animal. Thirty-eight embryos were collected by the non-surgical method, 29 of these being normal in development and it morphology normal. After 21 transfers using the surgical method 15 (71%) recipients became pregnant. Two out of 6 (33%) recipients treated by the non-surgical method sustained the pregnancy. It is concluded that the surgical method for bovine embryo transferis still the most efficient. However, the need for rapid improvement is the non-surgical method is stressed, due to its simplicity and easy manipulation in the field.

• Bovine embryo transfer

Abstract in Portuguese:

Durante outubro e dezembro de 1980 foi desenvolvido um estudo na área de transferência de embriões em bovinos no Rio Grande do Sul. Como doadoras foram utilizadas 25 fêmeas das raças Hereford (10), Aberdeen-Angus (4), Normanda (6) e Charolesa (5). Para receptoras foram selecionadas vacas cruza Holandesa e das raças supracitadas. Obteve-se a sincronização do ciclo estral e superovulação através da aplicação de um análogo de prostaglandina 7 F2 alfa e de PMSG8. Das 25 vacas superovuladas 14 (56%) responderam ao tratamento com PMSG com uma média de 6,2 C.1./animal. Foram coleta- dos 38 embriões pelo método não cirúrgico, sendo 29 (76% com morfologia e desenvolvimento normais. Após 21 transferências pelo método cirúrgico, 15 (71%) receptoras resultaram gestantes; após 6 pelo não cirúrgico 2 (33%) receptoras mantiveram a gestação. Conclui-se ainda que o método de transferência cirúrgica é o mais eficiente e que há a necessidade de acelerar-se o aperfeiçoamento do método de transferência não cirúrgico em função da simplicidade e rapidez da manipulação para trabalhos a nível de campo.

• Bovino transferência de embrião

Abstract in English:

Five outbreaks of intoxication by the fungus Claviceps paspali in cattle in the State of Rio Grande do Sul, Brazil, are described. The disease which occurred during April and May, 1982, was cause d by the ingestion of infected seed heads of Paspalum dilatatum and Paspalum notatum. The main clinical sigos observed were staggering and ataxia. The morbidity rate was 12,8% and mortality rate 1,8%, with cattle of both sexes and various ages being affected. Three animals necropsied had an increased cerebrospinal fluid volume, two showing subdural hemorrhages in the spinal cord. The main histological lesions were degenerative changes of Purkinje cells. In one case axonal spheroids in the cerebellar granular layer were observed. The intoxication was reproduced experimentally in three calves. One of these animals was killed and at necropsy showed increased cerebrospinal fluid vólume, subdural hemorrhages in the spinal cord and degeneration of Purkinje cells; the other two recovered 5 days after the last administration of infected seeds. The average monthly precipitation during March and April, 1982, was considerably lower than normal values for the region. It is conceivable that this drought may have modified the environment to the extent that a) sufficient green forage·was no longer available, b) the production of seed heads was considerably increased and/or c) the level of infection by C. paspali in the grass was increased. These changes may have ultimately been responsible for the occurrence of at least 33 outbreaks of the disease in the State.

• Mycotoxicosis cattle Claviceps paspali Paspalum staggers

Abstract in Portuguese:

Descrevem-se cinco surtos de intoxicação por Claviceps paspali em bovinos no Rio Grande do Sul. A doença ocorreu nos meses de abril e maio de 1982 e foi causada pela ingestão de sementes de Paspalum dilatatum e Paspalum notatum infectadas pelo fungo. Os principais sintomas observados foram tremores musculares e ataxia. A morbidade foi de 12,8% e a mortalidade de 1,8%, sendo afetados animais de diversas categorias. Três animais necropsiados apresentaram aumento de líquido cefalorraquidiano, e dois deles, hemorragias subdurais na medula. Histologicamente observou-se degeneração das células de Purkinje e, em um caso, numerosos esferóides na capa granular do cerebelo. A doença foi reproduzida experimentalmente em três bezerros. Um foi sacrificado, observando-se, na necropsia, aumento do líquido cefalorraquidiano, hemorragias subdurais na medula e alterações degenerativas das células de Purkinje. Nos dois restantes, os sintomas clínicos desapareceram totalmente cinco dias após terem deixado de·ingerir a planta. O estudo dos dados climáticos mostrou que nos meses de março e abril de 1982 as precipitações pluviais foram consideravalmente menores que as normais para a região. Admite-se que alguns aspectos epidemiológicos teriam sido modificados pela estiagem, determinando a ocorrência dos surtos descritos e de pelo menos outros vinte e oito surtos constatados no Estado durante o outono de 1982. Três desses fenômenos são sugeridos como prováveis fatores desencadeantes: a) diminuição de disponibilidade de forragem verde; b) concentração da frutificação gramínea; c) aumento da taxa de infecção de Paspalum por Claviceps paspali e/ou de seu conteúdo em toxinas.

• Micotoxicoses bovinos Claviceps paspali Psapalum dilatatum Paspalum notatum tremores musculares