ABSTRACT This study aimed to evaluate the influence of management times and methods of black oat straw on corn crop development and yield under a no-tillage system for two crop seasons. A randomized block design was used with twelve treatments. They were arranged in a 3 x 4 factorial scheme with four replications, consisting of a combination between three methods (crushed, rolled, and desiccated) and four times (0, 10, 20, and 30 days before corn sowing). Black oat was evaluated for dry matter, while corn was for plant final population, height, stem diameter, ear insertion height, ear diameter, ear length, grain number per row, 1000-grain weight, and grain yield. All management methods and times interfered with corn crop yield components, but not all influenced final production. The method with the largest final corn population was not the same with an improved ear development. Such findings, however, may not be the same under highly favorable weather conditions.

ABSTRACT Ground Penetrating Radar (GPR) is a geophysical method that uses electromagnetic waves to study subsurface structure in different fields such as geology, agriculture and civil engineering. The wave penetration in the soil is strongly controlled by the electrical conductivity of soil components such as clay, organic matter, and water. In this study, tests were conducted in a floodplain in the Elizabeth Creek watershed (New Jersey – USA). We established one transect where measurements were completed using two techniques, common mid point (CMP) and constant offset profile (COP), both with 100- MHz frequency antennas. Measurements were also completed using 250 and 500 MHz shielded antennas. GPR showed good accuracy to study soil spatial variability and stratigraphy. Antennas of a higher frequency had less vertical investigation capacity and greater accuracy. In this study, it was not possible to clearly differentiate signals from organic matter and clay; this was the main limitation of the GPR system.

ABSTRACT Direct seeding systems are characterized by soil disturbance only occurring in the sowing line and the maintenance of the remaining area is achieved by covering with crop residues. Without total area soil mobilization as recommended by the no-tillage system, associated with the increase in the degree of soil compaction caused by the traffic of agricultural machinery, there can be a decrease in crop productivity. This study aimed to evaluate machine parameters, soil mobilization, and corn yield as a function of different furrow opener working depths (0.065, 0.095, 0.125, and 0.150 m) and evaluate the direct seeding of winter ground cover plants (black oat or forage turnip) in compacted Oxisol. The experiment was arranged in strips, in a randomized block design, with eight treatments and four replications. The deepening of the furrow opener shank increased the strength and power required at the drawbar in the seeding operation, as well as increased the soil mobilization in the seeding line. However, it did not prove to be an efficient management practice to increase corn productivity.

Enterotoxemia, uma das mais comuns enfermidades que acomete os pequenos ruminantes domésticos, é causada principalmente pela toxina épsilon de Clostridium perfringens tipo D. O presente estudo avaliou a resposta humoral conferida por quatro protocolos distintos de primovacinação na progênie de ovelhas não vacinadas durante a gestação. Vinte e quatro cordeiros foram aleatoriamente divididos em quatro grupos de acordo com a idade (dias) que receberam a primeira dose da vacina comercial contra clostridiose contendo toxóide epsilon na sua formulação. Todos os cordeiros foram vacinados aos 7, 15, 30 ou 45 dias de idade e receberam um reforço da dose 30 dias após a vacinação. A avaliação sorológica dos cordeiros pelo teste de ELISA indireto foi realizada por ocasião da administração da primeira dose da vacina. Os resultados elucidaram não haver comprometimento da resposta imune de cordeiros vacinados tanto aos 7, 15, 30 ou 45 dias de idade associada ao reforço da dose 30 dias após, demonstrando assim que a antecipação da primeira vacinação conferiu proteção aos cordeiros contra a enterotoxemia, permitindo otimizar o planejamento da vacinação em massa dos cordeiros.

Enterotoxaemia, a common disease that affects domestic small ruminants, is mainly caused by the epsilon toxin of Clostridium perfringens type D. The present study tested four distinct immunization protocols to evaluate humoral response in lambs, a progeny of non-vaccinated sheep during gestation. Twenty-four lambs were randomly allocated into four groups according to age (7, 15, 30 and 45 days), receiving the first dose of epsilon toxoid commercial vaccine against clostridiosis with booster after 30 days post vaccination. Indirect ELISA was performed after the first vaccine dose and booster to evaluate the immune response of the lambs. Results showed that for the four protocols tested all lambs presented serum title considered protective (≥0.2UI/ml epsilon antitoxin antibodies) and also showed that the anticipation of primovaccination of lambs against enterotoxaemia conferred serum title considered protective allowing the optimization of mass vaccination of lambs.

Enterotoxemia, uma das mais importantes enfermidades que acomete os pequenos ruminantes domésticos, é causada principalmente pela toxina épsilon de Clostridium perfringens tipo D. O presente estudo avaliou a cinética de anticorpos colostrais antitoxina épsilon em cordeiros nascidos de ovelhas submetidas a dois diferentes tipos de manejo sanitário. Um grupo de ovelhas prenhes (n=6) foi vacinado com uma dose única de vacina comercial polivalente contra clostridioses contendo toxóide épsilon na sua formulação cerca de 30 dias antes da data prevista para a parição. Outro grupo de ovelhas (n=6) de mesma idade gestacional não foi vacinado. Imediatamente após o parto, antes da ingestão do colostro, foram colhidas amostras sanguíneas dos respectivos cordeiros, bem como aos 30 e 60 dias de idade e submetidas à avaliação sorológica pelo teste de ELISA indireto. Os resultados encontrados permitem concluir que a vacinação de ovelhas prenhes 30 dias antes do parto contra a enterotoxemia causada pela toxina épsilon, com dose única de produto comercial, induz imunidade passiva em níveis considerados protetores (>0,5UI/ml) aos cordeiros por, no mínimo, 60 dias de idade.

Enterotoxemia, a disease that affect small ruminants, is caused mainly by the epsilon toxin from Clostridium perfringens type D. This study evaluated the kinetics of epsilon antitoxin colostral antibodies in lambs born to ewes submitted to two different types of health management. A group of pregnant ewes (n=6) was vaccinated with a single dose of commercial vaccine against polyvalent clostridial toxoid containing epsilon in its formulation some 30 days before the expected date of birth. Another group of ewes (n=6) of the same gestational age were not vaccinated. Immediately after birth, before intake of colostrum, blood samples were collected from their lambs as well as 30 and 60 days of age for serum evaluation by ELISA. The results allow to conclude that vaccination of pregnant ewes 30 days before parturition allowed the transfer of colostral antibodies specific enough to guarantee the immunity considered protective (0,5UI/ml) of the newborn lamb against enterotoxemia until its entry into the feedlot, with 60 days of age.

Objetivando avaliar a ocorrência de anticorpos anti-Toxoplasma gondii, em caprinos leiteiros do estado de São Paulo, e verificar possíveis associações com idade, sexo, presença de gatos, problemas reprodutivos e potenciais riscos à saúde pública, foram considerados soros de 923 caprinos, de ambos os sexos e idade acima de três meses, provenientes de 17 propriedades de diferentes municípios. Para o diagnóstico, utilizou-se a reação de imunofluorescência indireta (RIFIe"16) e, também, um inquérito sobre saúde, a fim de se coletarem informações epidemiológicas e de esfera reprodutiva de todos os capris. Os resultados foram discutidos no nível de 5% de significância. Do total das 17 propriedades, foram diagnosticados 15 focos de T. gondii, com positividade entre 2,70% e 81,25%. Não foram verificadas associações entre freqüência de soropositividade e sexo dos animais nem ocorrência de falhas reprodutivas, nos capris. Constatou-se influência positiva na taxa de anticorpos anti-T. gondii pelo aumento da idade dos caprinos e presença de gatos, nos capris. Além de a enfermidade encontrar-se amplamente difundida no estado de São Paulo, o risco eminente de transmissão de T. gondii à saúde pública também deve ser considerado, uma vez que se encontraram focos onde se comercializavam produtos "in natura", como leite e carne.

The study evaluated the anti-Toxplasma gondii antibodies occurrence in dairy goats in São Paulo State, and also verified likely associations with age, sex, presence of cats, occurrence of reproductive problems, and potential risks to public health. Serum was obtained from 923 animals of both sex, over three months of age from 17 properties in different cities. For the diagnosis, the indirect immunofluorescence reaction (RIFIe"16) and a questionnaire about health to collect epidemiological information and the reproductive cycle of every goat were used. Among all properties, 15 foci of T. gondii were diagnosed with seropositivity ranging from 2.70% to 81.25%. Neither association between the frequency of seropositivity and the sex of animals nor occurrence of reproduction failure of goats was identified. There was positive influence of anti-T. gondii antibody rate due to the older age of the animals and the presence of cats in pens. The risk of transmitting T. gondii to the public health must be considered, once in some properties where the positive serology was verified natural, products such as milk and/or meat are commercialized. Results were discussed at 5% level of significance.

Com o objetivo de se avaliar a freqüência de caprinos leiteiros soropositivos para Neospora caninum, no estado de São Paulo, e se verificarem possíveis associações com idade, sexo e problemas reprodutivos, nos capris, e, também, presença de cães, nas propriedades, foram obtidos soros de 923 caprinos de ambos os sexos e idade acima de 3 meses. Os animais eram provenientes de 17 propriedades de diferentes municípios. Para o diagnóstico, foi utilizado o teste de aglutinação para Neospora (NATe"25), e, em todos os capris, aplicou-se um inquérito a partir do qual se obtiveram informações epidemiológicas e de esfera reprodutiva. Todos os resultados estatísticos foram discutidos no nível de 5% de significância. Assim, chegou-se à conclusão de que a freqüência percentual de positividade para N. caninum foi de 19,77%, e, em apenas uma propriedade, não houve registro de animal soropositivo, o que revela difusão do agente, no Estado. Não foram verificadas diferenças significativas entre freqüências de positividade quanto ao sexo, idade ou problemas reprodutivos. Porém, ressalta-se que a presença de cães, nos capris, foi associada a uma maior freqüência de caprinos soropositivos a N. caninum. A representação geográfica da distribuição de caprinos soropositivos para o protozoário, em mapa coroplético em hachuras, pode implicar em um ganho considerável para estudos da epidemiologia geográfica, na elaboração de um planejamento de controle da enfermidade.

In order to assess the frequency of dairy goats seropositive for Neospora caninum in the state of São Paulo, and its relationship with age, sex, presence of dogs and reproductive problems in goat pens, serum samples were obtained from 923 goats of both sexes older than 3 months of age. Samples were collected in 17 properties located in different municipalities. Neospora agglutination test (NATe"25) was used to determine the presence of Neospora caninum in all animals. Epidemiological and reproductive data were obtained through a questionnaire which was administered in all goat pens. Significance level was set at 5% for all statistical tests. N. caninum positivity rate was 19.77%. Only one of the properties had no seropositive animal revealing N. caninum diffusion in the state. Seropositivity frequency did not correlate with sex, age, or reproductive problems. However, the presence of dogs was associated with a higher frequency of N. caninum seropositivity. A choroplethic map with hatch patterns showing the geographical distribution of goats seropositive for Neospora caninum may considerably contribute to geographic epidemiological studies and the development of disease control strategies.