Comparison of metabolic and immune biomarkers between primiparous and multiparous dairy cows during the peripartum period
Résumé
The peripartum period can decrease immune capacity leading to a higher risk of infectious diseases. The objective of this study was to investigate the influence of parity on metabolic biomarkers (NEFA, glucose, β-hydroxybutyrate, urea) and immunity (cytokines) before calving and at the beginning of lactation. Fifteen Holstein cows were classified into 4 groups according to calving date with 7 primiparous heifers and 8 multiparous cows. Blood samples were collected 3 weeks before calving, and 4, 8, 12 weeks postpartum and milk was samples at the same times only after calving. Cows were fed ad libitum a total mixed diet based on maize silage and milked twice a day. Milk minerals were measured by ICP-OES. In the plasma, metabolic markers were analyzed by spectrophotometry. Plasma pro- and anti-inflammatory cytokines were analyzed after an ex vivo challenge of whole-blood cells
with or without heat-killed Escherichia coli using a bead-based multiplex assay. Data were analyzed with a mixed model including parity, week, and their interaction as fixed effects, and cow as a random effect. Milk production was higher in multiparous than in primiparous cows (x vs y kg/d on average over 12 weeks). During the first weeks of lactation, NEFA and BOH (parity x week interaction effect), and urea (parity effect) were higher in multiparous cows, whereas glucose was lower. Milk cell count was lower in multiparous than in primiparous cows in the 2nd week after calving but was always lower than 100,000 cells/mL. Parity did not affect the integrity of the mammary epithelium (milk Na+/K+ ratio). The key inflammatory cytokines CXCL10, CCL2, IL1Rα and IFNγ were lower in the plasma of multiparous cows. At the 3rd week before and the 8th week after calving, the immunity of multiparous cows
could be less effective with lower levels of IL1α and TNFα, compared with primiparous cows. The parity effects on immunity contrasted with what is observed for the metabolic markers and milk production. The effect of parity must be considered for the research studies of immunity in dairy cows during the peripartum period.
Origine : Fichiers produits par l'(les) auteur(s)
Licence : CC BY NC ND - Paternité - Pas d'utilisation commerciale - Pas de modification
Licence : CC BY NC ND - Paternité - Pas d'utilisation commerciale - Pas de modification