Abstract
In January, 1978, four fattening cattle which died one after another were examined bacteriologically. Haemophilus somnus was isolated from principal organs of three of them. It was examined for morphological and biological properties and proved to be highly susceptible for chloramphenicol and other seven anti-biotics.
When cattle raised in the same barn with the dead ones and exposed to contact infection were subjected to the sero-agglutination reaction with the isolated organism as antigen, many of them exhibited high ag-glutination titers.
