EN
The aim of the present study was to determine the cooperative interactions among some non-specific humoral factors participating in the immune response of healthy suckling piglets and piglets with diarrhea caused by E.coli at different ages. A total of 168 hybrid piglets (aged 12 to 18 days and 19 to 25 days), clinically healthy and suffering from diarrhea, were examined. The serum levels of lysozyme, ceruloplasmin (CP) and C-reactive protein (CRP) were determined in randomly selected sibs (clinically healthy piglets and piglets with diarrhea). Feces samples were taken from piglets with diarrhea to identify E. coli strains. A positive correlation between lysozyme activity and the serum concentration of CP was observed in healthy animals. This shows that over the experimental period the values of both these indices increased along parallel lines at a relatively stable CRP level. Elevated serum levels of lysozyme, CP and CRP in piglets with diarrhea caused by E. coli, as compared with healthy piglets, reflected the participation of these non-specific humoral factors in the immune response against E. coli. The increase in lysozyme activity, resulting from the immune response, was parallel to the increase in CP concentration (a positive correlation), but not parallel to the increase in CRP concentration (a negative correlation). These changes were found to be age-related. In younger piglets, the lysozyme activity was significantly correlated with CRP level but in older ones with level of CP.