Confirmação de infecção por Brucella abortus em um rebanho bovino certificado livre em Minas Gerais: relato de caso

Relata-se a ocorrência de um surto de brucelose em um rebanho de aproximadamente 1000 animais, livre da doença há 18 anos, certificado pelo Ministério da Agricultura, Pecuária e Abastecimento desde 2006. Dois animais reagiram aos testes sorológicos de diagnóstico por ocasião dos procedimentos de recertificação em 2008. Após o sacrifício deles, Brucella abortus, biovariedade 1, amostra não vacinal, foi isolada e identificada por meio de provas bioquímicas e de biologia molecular (PCR AMOS). A origem do agente no rebanho é de difícil determinação. No entanto, a adoção de procedimentos preconizados pelo Programa Nacional de Controle e Erradicação da Brucelose permitiu evitar a disseminação da enfermidade. Ocorrências como essas, em que rebanhos livres foram infectados após anos sem a ocorrência de brucelose, nunca haviam sido relatadas no Brasil

Surface application and shallow injection of cattle slurry on grassland: nitrogen losses, herbage yields and nitrogen recoveries

An experiment was carried out over 2 years on grass and grass/clover swards in SW England to compare herbage yields and N recovery following surface application or shallow injection of cattle slurry at three different times of application. In the second year, losses of N via ammonia volatilization, denitrification and nitrate leaching were measured from applications to the grass sward. On the grass sward, there was no significant effect of time or method of application on dry-matter (DM) yield in the first year, although shallow injection reduced apparent N recovery (ANR) in the herbage by 45% when compared with surface application. In the second year, shallow injection reduced DM yields by 26% and ANR by 48%. On the grass/clover sward, there were no significant effects of time or method of application on DM yields or AWR in either year. Inclusion of dicyandiamide (DCD) in the October slurry applications had no significant effect in the first year, but in the second year on the grass sward increased DM yield by 31% and 14% and ANR by 156% and 42% for shallow injection and surface applications respectively. Measurements in the second year on the grass award showed a reduction in N loss by ammonia volatilization using shallow injection of 40% and 79% for March and June applications respectively. Losses due to denitrification were greatest following October application, Shallow injection increased denitrification losses following March application, but there were no significant differences following October or June applications. N losses due to leaching were small, with no significant difference between treatments. Reasons for the reductions in DM yield and ANR following shallow injection, despite the large reduction in N loss by ammonia volatilization. are discussed