Association of post-parturient endometritis with serum metabolites, cortisol and neutrophil function over an extended sampling period in dairy cows
Background: In dairy cows, the development of endometritis following parturition can adversely affect reproduction, leading to subfertility. The metabolic profile, serum cortisol and peripheral blood neutrophil phagocytic ability of cows that develop endometritis have yet to be fully characterized over an extended period. Objectives: To determine the temporal changes in serum metabolites, serum cortisol and neutrophil phagocytic ability during the extended pre- and post-partum period and relate this to the development of endometritis in dairy cows. Methods: Blood samples were collected from 40 dairy cows (Canadian Holstein) five weeks before the expected calving date and then repeated biweekly until seven weeks postpartum (eight samples/animal). Serum glucose, calcium, beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), urea and cortisol concentrations were measured. Peripheral blood neutrophil phagocytic ability was evaluated using flow cytometry. Cows with endometritis (> 18 % neutrophils/100 cells) were identified at five weeks postpartum using a cytological evaluation of uterine cytosmears collected using the modified cytobrush technique. Results: Twelve out of 40 cows (30 %) were diagnosed with endometritis around five weeks postpartum. Compared to non-endometritic cows, endometritic cows had higher glucose concentrations at parturition (P < 0.01) and seven weeks postpartum (P = 0.02), higher calcium concentrations one week prior to parturition (P = 0.02) and at parturition (P = 0.02), and higher BHB concentrations one week following parturition (P = 0.03). Furthermore, endometritic cows had lower peripheral neutrophil counts (P < 0.01) with a lower neutrophil phagocytic ability (P = 0.05) at one week postpartum than their non-endometritic counterparts. The NEFA, urea, or cortisol concentrations did not differ between the two groups over the sampling period. Conclusions: Based on the current data, the development of endometritis was associated with higher serum concentrations of total calcium one week prior to parturition, higher serum glucose and total calcium at parturition, and higher BHB concentrations, lower peripheral blood neutrophil count and lower phagocytic ability one week following parturition. Monitoring of these key metabolites may aid in the early identification of at-risk cows.
Neutrophil, Bovine Medicine, Endometritis
Master of Science (M.Sc.)