Major Acute Phase Proteins in Pig Serum from Birth to Slaughter

Age-related changes in serum concentrations of C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA), and pig major acute phase protein (pig-MAP) were investigated in healthy pigs from birth to slaughter under field conditions. Repeated blood samples were obtained from 60 pigs at ages of 1-19 weeks. Concentrations of acute phase proteins (APP) were measured with the use of commercial ELISA kits. Concentrations of all APP increased with age (P<0.05) and positive correlations were evidenced between their concentrations and the age of pigs. Great variations in CRP, Hp, and SAA concentrations were found, as can been seen from standard deviation values. The minimal individual variability was found in regard to pig-MAP. A significant increase in all APP was observed in pigs’ serum after weaning, constituting an important characteristic of this period. The elevation of APP after weaning may be associated with stress induced by mixing animals after weaning or changes in the pattern of feed administration. The peak in APP may be also caused by the initiation of synthesis of these proteins by piglets. Because a significant association between age and APP concentrations exists, further studies are needed to decide whether the age may influence the diagnostic value of APP as a marker of infection. Additionally, studies are needed to estimate whether the APP response in infection is age-dependent to any clinical importance degree.