RESUMO
El uso de probióticos de levadura mejora el aumento de peso corporal y el sistema inmunológico del ganado sometido a los desafíos de la cría, sin embargo, la pregunta sigue siendo si los probióticos podrían tener un efecto en desafíos más tenues. De esta manera, el presente estudio verificó si el uso de probióticos (Enterococcus faecium y Saccharomyces cerevisiae) proporcionado por vía oral interfiere con la inmunidad innata y el peso corporal de los terneros alimentados principalmente con ensilaje de maíz. Doce terneros de Jersey (120 kg ± 50 kg y 4-7 meses de edad) se asignaron al grupo control (n = 6) o tratamiento (n = 6) según el suministro de probióticos (2 g / día, por vía oral) para 45 dias. En los días 0, 15, 30 y 45, los animales se pesaron y se sometieron a exámenes clínicos y se recogieron muestras de sangre para el hemograma y la medición del metabolismo oxidativo de los neutrófilos. Se observó que el probiótico promovió un aumento leve y puntual de la función neutrofílica en sangre (P = 0,10, D15), aumento de los valores de hematocrito y hemoglobina (P = 0,03 y 0,05, D45) y aumento de la ganancia de peso corporal en las fases iniciales de la suplementación. (P = 0.08), lo que permite concluir que el probiótico es beneficioso para los animales en la fase de adaptación de los cambios y el manejo de la dieta, incluso cuando estos desafíos son leves.
The use of yeast probiotics improves body weight gain and the immune system of cattle submitted to husbandry challenges, however the question remains whether the probiotics could have an effect on more tenuous challenges. In this way, the present study verified if the use of probiotic (Enterococcus faecium and Saccharomyces cerevisiae) provided orally, interferes with the innate immunity and body weight of calves fed mainly with corn silage. Twelve Jersey calves (120 kg ± 50 kg and 4-7 months of age) were allocated to the control (n = 6) or treatment (n = 6) group according to the probiotic supply (2 g / day, orally) for 45 days. On days 0, 15, 30 and 45, the animals were weighted, and submitted to clinical examinations, and blood collection for hemogram and measurement of neutrophil oxidative metabolism. It was observed that the probiotic promoted a slight and punctual increase in blood neutrophilic function (P = 0.10, D15), increased hematocrit and hemoglobin values (P = 0.03 and 0.05, D45) and increased the body weight gain in the initial phases of supplementation (P = 0.08), allowing to conclude that the probiotic is beneficial for animals in the adaptation phase of diet changes and management, even when these challenges are mild.
O uso de probióticos a base de leveduras melhora o ganho de peso e o sistema imunológico de bovinos frente a grandes desafios imunológicos, no entanto permanece a dúvida se seu uso também apresentaria efeito em desafios mais tênues. Desta maneira, o presente trabalho verificou se o uso de probiótico a base de Enterococcus faecium e Saccaromyces cerevisiae via oral interfere na imunidade inata e no peso de bezerros sadios, em fase de crescimento, alimentados principalmente com silagem de milho. Para tanto, 12 bezerros da raça Jersey (120 kg ±50 kg e 4-7 meses de idade), foram alocados nos grupos controle (n=6) ou tratamento (n=6), de acordo com a oferta de probiótico (2g/dia, via oral) durante 45 dias. Nos dias 0, 15, 30 e 45, os animais foram submetidos a pesagens, exames clínicos, e colheita de sangue para realização de hemograma e mensuração do metabolismo oxidativo neutrofílico. Observou-se que, o probiótico promoveu pequeno e pontual incremento na função neutrofilica sanguínea (P=0,10, D15), incremento nos valores de hematócrito e hemoglobina (P=0,03 e 0,05, D45), além de maior ganho de peso nas fases iniciais da administração do suplemento (P=0,05), permitindo concluir que o suplemento é benéfico para animais em fase de adaptação de trocas de dieta e de manejo, mesmo quando estes desafios são tênues.
RESUMO
The aim of this study was to evaluate the humoral antibody response, the genome viral excretion and the contact transmission of pathogenic chicken origin Newcastle disease virus (NDV) from experimentally infected pigeons (Columba livia) to in-contact pigeon. The antibody response to infection was assessed by the hemagglutination inhibition (HI) test and the genome viral excretion was detected by RT-PCR. Viral strain induced high antibody levels, both in inoculated and in sentinel birds. The pathogenic viral strain for chickens was unable to produce clinical signs of the disease in experimentally infected pigeons, although it induced the humoral antibody response and produced NDV genome shedding. NDV genome was detected intermittently throughout the experimental period, from 5 days post-infection (dpi) to 24 dpi. Therefore, viral genome shedding occurred for 20 days. The viral genome was detected in all birds, between 11 and 13 dpi. Furthermore, the high infectivity of the virus was confirmed, as all non-inoculated sentinel pigeons showed antibody levels as high as those of inoculated birds.