Efficacy of oral vaccination against swine erysipelas in growing-finishing pigs in a clinically infected Slovakian pig herd.

In a large Slovakian growing-finishing pig production unit, the effects of oral vaccination against swine erysipelas (SE) were investigated in three groups of pigs of 10 weeks of age. In group 1, the pigs were vaccinated intramuscularly at 1 and 3 weeks after arrival in the growing-finishing barn using an Erysipelothrix rhusiopathiae bacterin. Group 2 pigs were vaccinated at the same time as group 1 using an oral avirulent live SE vaccine administered through drinking water; the pigs in the third group were placebo treated. Clinical signs of acute SE, arthritic changes, average daily weight gain (ADG), feed conversion ratio, and mortality were evaluated. None of the pigs in groups 1 and 2 but 31.7% of the control animals (group 3) showed typical clinical signs of acute SE. More (P<0.01) non-vaccinated pigs had chronic arthritic changes compared with groups 1 and 2. No significant differences in mortality were recorded between the groups. Groups 1 and 2 had higher (P<0.05) ADG and lower feed conversion ratios compared with group 3 pigs. The results demonstrated that the oral avirulent live culture was efficacious in significantly reducing the clinical symptoms caused by E. rhusiopathiae infection, so enhancing the pigs' performance.