Numerical variations among blood mononuclear cells during the peripartal period in the gilt

Numerical variations among mononuclear cells (MNC) were studied in blood collected from nine cross-bred primiparous gilts during two weeks before and two weeks after parturition. Simultaneously, the plasma levels of cortisol and oestrone sulphate were measured. The number of polymorphonuclear cells (PMNs) increased significantly (p less than 0.05) at parturition, while the number of MNCs decreased significantly (p less than 0.01) at the same time. Concomitantly with the total number of MNCs, the proportion of Ig-bearing MNC (Ig(+)-cells) also decreased significantly (p less than 0.01). No considerable variations of the proportion of MNCs expressing MHC Class II antigen could be seen throughout the study. The proportion of MNC with receptor for the Fc-part of IgG decreased significantly (p less than 0.01) during the week preceding parturition, but increased (p less than 0.05) again at parturition. The proportion of Ig(+)-cells was positively correlated both to the plasma level of oestrone sulphate and cortisol, while the number of Ig(+)-cells was only positively correlated to the level of cortisol. Thus, the study shows considerable numerical variations within the leukocyte sub-populations in the gilt around parturition.