|Waldron, M - CORNELL UNIV, ITHACA, NY|
|Nishida, T - CORNELL UNIV, ITHACA, NY|
|Overton, T - CORNELL UNIV, ITHACA, NY|
Submitted to: American Dairy Science Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 24, 2001
Publication Date: N/A
Technical Abstract: Four multiparous lactating cows (175-220 DIM) were used in a 4x4 Latin square design to assess the effects of increasing doses (0.0, 0.5, 1.0, 1.5 ug/kg BW) of lipopolysaccharide (LPS; E. coli O11:B4) on performance and blood metabolites. Treatments were dissolved in 100 ml of sterile saline and infused intravenously over a period of 100 min. Milk production was decreased linearly for 24 h after LPS infusion (34.9, 22.4, 22.0 and 16.5 kg; P less than 0.001) and generally returned to preinfusion levels by the sixth milking following LPS infusion. The DMI also was decreased linearly for 24 h following LPS infusion (21.2, 17.6, 15.5 and 10.9 kg; P less than 0.01) and regained preinfusion levels 3 d following infusion. Blood was sampled immediately before infusion (0 h), at 60-min intervals for 8 h, and at 24 and 48 h postinfusion. Reported means for hormone and metabolite concentrations with treatment by time effects are at the 3 h timepoint. Plasma insulin, glucagon, and cortisol concentrations increased linearly following LPS infusion (treatment by time P less than 0.01). Plasma (L+)-lactate concentrations (5.83, 7.43, 7.95 and 6.63 mg/dl) increased f9ollowing LPS infusion (treatment, P less than 0.001). There was a linear decrease (treatment by time, P less than 0.01) for plasma BHBA (9.8, 5.3, 4.4 and 2.9 mg/dl) after infusion. Plasma NEFA were increased by the 1.5 ug LPS/kg BW treatment (204, 185, 198 and 260 mg/dl fo4r 0.0, 0.5, 1.0, 1.5 ug LPS/kg BW, respectively; P=0.037). There was no effect of LPS infusion on plasma glucose concentrations (P more than 0.2). These data suggest that the inflammatory response elicited by LPS had dose-dependent metabolic consequences that may be important for metabolic health in dairy cows.