[en] The interest in the immunology and endocrinology aspects of the peripartum in dairy cows has been increasing in the last years, since the animal status during the pre- and postpartum period determines the subsequent productive and reproductive performance of the animal. At parturition, a drop in the immune functions of the peripheral blood polymorph-nuclear cells (PMN) was observed after a peak of Pregnancy-Associated Glycoproteins (PAGs) and recently, the inseminating bull was found to affect the plasma levels of bovine Pregnancy-Associated Glycoproteins (bovine PAGs) in the pregnant Holstein-Friesian dairy cows. The present work was aimed to determine whether changes in leukocyte counts during the peripartum, indicative of the animal immune status, could be related to the inseminating bull and to the levels of plasma pregnancy-associated glycoproteins (PAGs). Ninety six clinically healthy, single pregnant cows were selected in a commercial dairy herd. Six blood samples (four prepartum and two postpartum) were obtained every two weeks, and total and differential blood cell counts were analyzed. Based on procedures of General Linear Model analysis of variance for repeated measures, the inseminating bull affected counts of total leukocytes and lymphocytes (P<0.001; between-subject effects) throughout the peripartum period. In addition, cows with high plasma levels of PAGs (>900 ρg/µL) on Day 262-268 of gestation had higher numbers of total leukocytes and neutrophils throughout the peripartum period (P<0.001; between-subject effects). Young animals (≤ 1 lactation) had higher total leukocyte and lymphocytes counts than older cows (two or more lactations) throughout the study period. These results showed a clear relationship between the inseminating bull and plasma PAG levels and peripheral leukocyte counts during the peripartum period of dairy cows.
Spanish CICYT grants AGL2010-21273-C01/GAN and AGL2010-21273-C02/GAN. Spanish Ministry of Science and Innovation, MICINN, BES-2008-9883