Effect of feeding regimen on concentration of free endotoxin in ruminal fluid of cattle

J Anim Sci. 1994 Feb;72(2):487-91. doi: 10.2527/1994.722487x.


The influence of concentrate diets on endotoxin concentration in sterile filtrate of ruminal fluid was assessed in ruminally fistulated Jersey cows. Three cows underwent a change in diet from hay to a diet containing 3.0 kg and 14 d later 6.0 kg of a 12% CP concentrate. The cows had free access to water and a mineral-stone. A modified Limulus Amoebocyte Lysate technique was used for the endotoxin analyses. The endotoxin concentration in the ruminal fluid of cows fed on hay were 148 +/- 84 and 118 +/- 50 endotoxin units (EU)/mL (mean +/- SD) on two separate days and increased from the 2nd d of supplementation with 3.0 kg of concentrate to 408 +/- 198 EU/mL on d 5. When the cows were fed 6.0 kg of concentrate, the endotoxin concentrations increased to 1,599 +/- 944 EU/mL. To assess the influence on the ruminal endotoxin concentration of an adaptation of the ruminal environment to concentrate before hyperalimentation, four ruminally fistulated Jersey cows previously fed either hay or a high-concentrate diet for 1 mo were hyperalimented with 60 to 70 g of barley per kilogram BW. A relative increase in ruminal endotoxin concentration was determined only in the two cows previously fed concentrates. The results show that high-concentrate diets do not consistently relate to increases of ruminal endotoxin concentrations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological*
  • Animal Feed*
  • Animals
  • Cattle / metabolism*
  • Eating
  • Endotoxins / analysis*
  • Evaluation Studies as Topic
  • Female
  • Hydrogen-Ion Concentration
  • Limulus Test / veterinary
  • Osmolar Concentration
  • Rumen / chemistry*
  • Sensitivity and Specificity


  • Endotoxins