Isolation of Erysipelothrix rhusiopathiae from apparently healthy pigs reared under intensive and free range systems of management.

The carriage of Erysipelothrix rhusiopathiae by pigs reared under free range and intensive systems of management was compared. Large white (exotic) breeds kept under an intensive system and local (native) breeds kept under a free range system were studied. Of the 29 pigs kept under the intensive system, 44.8% carried E. rhusiopathiae in their tonsils while 51.7% of pigs kept under free range system also carried the organism in their tonsils. In each of the systems 6.9% of the pigs carried E. rhusiopathiae in their bile and muscles. Blood samples from all the animals surveyed were negative for the organism. There was no significant difference in the carriage of E. rhusiopathiae in pigs reared under the two systems of management. The ubiquity of E. rhusiopathiae in the environment, its resistance to environmental influences, poor standards of hygiene and the problem of detecting apparently healthy animals, are possible epidemiological factors which may have increased the carrier rate in the intensive system where E. rhusiopathiae was supposed to be less. The total number of carrier-pigs in the intensive system was 44.8% while in the free range system it was 51.7%.