Abstract
Summary: 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 < 0.05) at parturition, while the number of MNCs decreased significantly (p < 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 < 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 < 0.01) during the week preceding parturition, but increased (p < 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.