Development of selected faecal microfloras and of phagocytic and killing capacity of neutrophils in young pigs.

Nine healthy piglets, weaned at the age of 35 days and emanating from two litters, were studied from 7 to 63 days of age. The development of their faecal flora was analysed by bacteriological quantification of coliforms, E. coli, enterococci and Clostridium perfringens. The numbers of coliforms, E. coli and enterococci decreased from about 10(8) CFU/g faeces on day 7 to about 10(5) at the end of the study. Clostridium perfringens, with an initial value of 10(4) CFU/g faeces, was not found in any faecal sample from day 21 onwards. At each sampling occasion the similarity between the floras of different pigs were investigated by biochemical fingerprinting and calculated as correlation coefficients between metabolic fingerprints. This was performed for the coliform and the enterococcal floras. Initially, the coliform floras had a low homogeneity (rmean = 0.6), indicating large initial differences between the piglets. From day 14 post-partum until weaning the homogeneity was stable at a high level (rmean = 0.9). On day 3 post-weaning a marked decrease of the homogeneity was seen (rmean = 0.5), which later returned to the level before weaning. The enterococcal floras had a high homogeneity (rmean = 0.8-0.9) through the study and was only slightly affected by weaning. The function and development of the phagocytic and killing capacity of neutrophil granulocytes was monitored by flow cytometry and chemiluminescence. No changes in these functions were seen over time or between litters.