Anti-Sarcocystis Antibodies in Lambs Deprived of Colostrum.

INTRODUCTION: The objective of this study was to evaluate the presence of anti-Sarcocystis spp. specific IgG antibodies in serum samples from precolostral lambs to determine the occurrence of transplacental transmission of Sarcocystis spp. in sheep. METHODS: Blood samples were collected from 80 ewes and their respective lambs, immediately after lambing and before colostrum ingestion, respectively. The presence of anti-Sarcocystis spp. IgG was evaluated in serum samples using the indirect fluorescent antibody test (IFAT). Positive samples of the lambs were submitted to titration and IFAT to detect anti-T. gondii and anti-N. caninum specific IgG. RESULTS: Anti-Sarcocystis spp. IgG was detected in 62.5% of the ewes (50/80) and in 4% of the lambs of the seropositive ewes (2/50). None of the lambs from seronegative ewes were positive. The final titers of the positive lambs were 80. No cross reaction was detected among the positive samples to anti-Sarcocystis spp., anti-N. caninum, and anti-T. gondii IgG. The detection of anti-Sarcocystis spp. antibodies in serum samples of lambs deprived of colostrum suggests transplacental transmission of infection. Thus, the vertical transmission may be an alternative route of infection of Sarcocystis spp. also in sheep. Further studies are warranted to confirm transplacental transmission in sheep and to explain the importance of this infection pathway.

Nitrogen fertilization strategies, morphogenetic and structural features in Brachiaria decumbens deferred for 95 days / Estratégias de adubação nitrogenada, características morfogênicas e estruturais em pastos de Brachiaria decumbens diferidos por 95 dias

The aim this work was to evaluate the morphogenic and structural characteristics of Brachiariadecumbens pastures to determine the most suitable nitrogen fertilization strategies, for pastures deferredfor a period of 95 days. Four strategies of fertilization at the beginning and end of the summer (0-0, 100-0, 50-50, 0-100 kg ha-1 N) were studied, respectively, with four replications. The strategy of 100 kg ha-1N applied at the end of the summer (0-100), followed the parceling strategy at the beginning and end ofthe summer (50-50) favored higher rates of leaf appearance and lower values of phyllochron. Greater rate of leaf elongation was observed for 0-100 strategy, resulting in 40% increase compared to pasturesthat were not fertilized. However, there was no effect of fertilization strategies on stem elongation rate,registering an average of 0.28 cm.dia-1. There was a higher blade:stem ratio for the stratum A (40 cmabove the soil) in all treatments, observing higher blade:stem ratio for strategies 0-100 and 50-50, atthis stratum. There was no effect for the total number of leaves and final leaf length. However, greaterstem lengths were observed in pastures with 0-100 fertilizer strategy, followed by the 50-50 strategy.The strategy of applying 100 kg ha-1 at the end of summer, followed by the strategy of 50 kg ha-1nitrogen divided at the beginning and end of summer, promote greater influence on the morphogenicand structural traits, in pastures deferred for 95 days.(AU)

O objetivo deste trabalho foi avaliar as características morfogênicas e estruturais de pastos de Brachiariadecumbens para determinar estratégias de adubação nitrogenada, mais adequadas para o pastejo diferidopor um período de 95 dias. Foram estudadas quatro estratégias de adubação no início e no final do verão(0-0, 100-0, 50-50, 0-100 kg.ha-1 de N), respectivamente, com quatro repetições. As estratégias de 100kg.ha-1 de N, aplicados no final do verão (0-100) seguidas da estratégia de parcelamento no início e finaldo verão (50-50) favoreceram maiores taxas de aparecimento de folhas, menores valores de filocrono.Maior taxa de alongamento foliar foi encontrada para estratégia 0-100, resultando num aumento de 40%em relação aos pastos que não foram adubados. Entretanto, não houve efeito das estratégias de adubaçãosobre a taxa de alongamento de colmo, registrando-se média de 0,28 cm.dia-1. As estratégias 0-100 e50-50 promoveram maior relação lâmina:colmo no estrato vertical A. Não foi verificado efeito emrelação ao número de folhas totais e ao comprimento final da folha. No entanto, maiores comprimentosde colmos foram observados nos pastos com estratégia de adubação 0-100, seguida da estratégia 50-50. A estratégia de aplicação de 100 kg.ha-1 no final do verão, seguida da estratégia de 50 kg.ha-1 deN parcelado no início e final do verão, promovem maior influência sobre as variáveis morfogênicas eestruturais em pastos diferidos por 95 dias.(AU)

Nitrogen fertilization strategies, morphogenetic and structural features in Brachiaria decumbens deferred for 95 days / Estratégias de adubação nitrogenada, características morfogênicas e estruturais em pastos de Brachiaria decumbens diferidos por 95 dias

The aim this work was to evaluate the morphogenic and structural characteristics of Brachiariadecumbens pastures to determine the most suitable nitrogen fertilization strategies, for pastures deferredfor a period of 95 days. Four strategies of fertilization at the beginning and end of the summer (0-0, 100-0, 50-50, 0-100 kg ha-1 N) were studied, respectively, with four replications. The strategy of 100 kg ha-1N applied at the end of the summer (0-100), followed the parceling strategy at the beginning and end ofthe summer (50-50) favored higher rates of leaf appearance and lower values of phyllochron. Greater rate of leaf elongation was observed for 0-100 strategy, resulting in 40% increase compared to pasturesthat were not fertilized. However, there was no effect of fertilization strategies on stem elongation rate,registering an average of 0.28 cm.dia-1. There was a higher blade:stem ratio for the stratum A (40 cmabove the soil) in all treatments, observing higher blade:stem ratio for strategies 0-100 and 50-50, atthis stratum. There was no effect for the total number of leaves and final leaf length. However, greaterstem lengths were observed in pastures with 0-100 fertilizer strategy, followed by the 50-50 strategy.The strategy of applying 100 kg ha-1 at the end of summer, followed by the strategy of 50 kg ha-1nitrogen divided at the beginning and end of summer, promote greater influence on the morphogenicand structural traits, in pastures deferred for 95 days.

O objetivo deste trabalho foi avaliar as características morfogênicas e estruturais de pastos de Brachiariadecumbens para determinar estratégias de adubação nitrogenada, mais adequadas para o pastejo diferidopor um período de 95 dias. Foram estudadas quatro estratégias de adubação no início e no final do verão(0-0, 100-0, 50-50, 0-100 kg.ha-1 de N), respectivamente, com quatro repetições. As estratégias de 100kg.ha-1 de N, aplicados no final do verão (0-100) seguidas da estratégia de parcelamento no início e finaldo verão (50-50) favoreceram maiores taxas de aparecimento de folhas, menores valores de filocrono.Maior taxa de alongamento foliar foi encontrada para estratégia 0-100, resultando num aumento de 40%em relação aos pastos que não foram adubados. Entretanto, não houve efeito das estratégias de adubaçãosobre a taxa de alongamento de colmo, registrando-se média de 0,28 cm.dia-1. As estratégias 0-100 e50-50 promoveram maior relação lâmina:colmo no estrato vertical A. Não foi verificado efeito emrelação ao número de folhas totais e ao comprimento final da folha. No entanto, maiores comprimentosde colmos foram observados nos pastos com estratégia de adubação 0-100, seguida da estratégia 50-50. A estratégia de aplicação de 100 kg.ha-1 no final do verão, seguida da estratégia de 50 kg.ha-1 deN parcelado no início e final do verão, promovem maior influência sobre as variáveis morfogênicas eestruturais em pastos diferidos por 95 dias.