Inflammation status weakly modulated by short-term feed restriction in suckling beef cows
Résumé
Variations in feed intake modify metabolism and may have putative effects on inflammation status. There is scarce data on suckling cows experiencing acute shifts in feed allowance. The objective was to study inflammation and metabolic responses to a short nutritional stress induced by experimental feed restriction (FR) after 9 weeks of lactation in lactating beef cows. Twenty-two primiparous Charolais cows underwent a 4-day FR to meet 50% of net energy requirements (FR1 wk9, FR2 wk12, FR3 wk13, FR4 wk14). Dry matter intake was measured and residual feed intake (RFI) was calculated on wk 1 to 8 of lactation when cows were allowed ad libitum intake of the same diet. RFI ranged from -0.01 to -0.69 for negative RFI (RFI-) and from 0.04 to 1.15 kg DMI/d for positive RFI (RFI+). Blood samples were collected from coccygeal vessels before AM feeding on days -13, -6, -1, +4, and +91 relative to FR1. Plasma was stored at -80°C until analyzed for IL-1ɑ, IL-8, IL-10, IL-17ɑ, MCP-1, MIP-1β, TNFɑ and VEGFɑ using Milliplex® Bovine Cytokine/Chemokine Panel (BCYT-33K-10, Merck, DE). Plasma stored at -20°C was analyzed for NEFA, glucose, β-hydroxybutyrate (βOH) and urea. Data were analyzed using mixed models and repeated measures with cow as random effect. In both RFI group, FR1 increased NEFA, βOH and urea concentrations, whereas glucose decreased between d-16 to d+4. IL-1ɑ, IL-10, MCP-1 and TNFɑ were closely correlated (Spearman: r > +0.8, P < 0.0001). Whatever the RFI group, IL-8 and VEGFɑ were increased by FR1. A significant interaction between RFI and day was observed for IL-1ɑ and TNFɑ with constant increase between d-6 to d+4 for RFI- cows, whereas no change was observed for RFI+. The relation between the effect of FR on cytokines and chemokines and RFI was observed despite large inter-individual variations. Although FR appears to increase the chemokine IL-8 and proinflammatory VEGFɑ, the lack of effects of FR on the other cytokines suggests that, in the presence of a weak modulation of the metabolic status, it has no marked effect on the inflammation status.
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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