Abstract
The prevalence of Treponema hyodysenteriae in faecal samples from healthy pigs of various ages in different farrowing units was investigated. Samples from herds designated as Category I were processed within 2 hrs. of sampling. Samples from herds designated as Category II were transported 2 to 3 days before cultivation procedures started. T. hyodysenteriae was demonstrated in 53.7 % to 93 % of the samples collected from Category I herds. No marked difference in the frequency of positive samples from the various age groups of pigs was found. In Category II herds, the organism was demonstrated in 10 % of the samples. The degree of beta-haemolysis shown by isolated strains was grouped into 3 groups: weak, moderate and strong. Strongly betahaemolytic strains, supposedly enteropathogenic, were demonstrated in all Category I herds. Such strains were found in 4.6 % to 25 % of the positive samples in these herds. In Category II herds, 2 out of 17 positive samples harboured strongly beta-haemolytic strains of T. hyodysenteriae. The amount of growth of T. hyodysenteriae on primary plates inoculated with sample material originating from the 2 categories of herds was mostly moderate or abundant. Strongly beta-haemolytic isolates originating from Category I herds produced abundant growth on primary plates in approx. 60 % of samples harbouring such strains. In samples from Category I herds with strains producing weak or moderate beta-haemolysis sparse and moderate amount of growth of the organism was predominant.