| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
1 Corresponding author: plaizier{at}ms.umanitoba.ca
The effects of grain-induced subacute ruminal acidosis (SARA) in lactating dairy cows on free ruminal lipopolysaccharide (LPS) and indicators of inflammation were determined. Four mid lactation dairy cows were divided into 2 groups of 2 cows and used in a repeated switchover design. During each period, SARA was induced in 2 animals for 5 subsequent days by replacing 25% of their total mixed ration (dry matter basis) with a concentrate made of 50% wheat and 50% barley. The other 2 cows acted as controls and were fed a total mixed ration diet in which 44% of dry matter was concentrate. On average, inducing SARA did not affect milk composition, increased the duration of rumen pH below 5.6 from 187 to 309 min/d, and increased free ruminal LPS concentration from 24,547 endotoxin units (EU)/mL to 128,825 EU/mL. Averaged across treatments, milk fat yield and milk protein yield were 0.66 and 1.00 kg/d, respectively. Rumen pH and milk fat data suggest that control cows also experienced ruminal acidosis, albeit a milder form of this disease than SARA cows. Serum LPS concentration in both control and SARA cows was less than the detection limit of <0.01 EU/mL for the assay. Induction of SARA elevated serum amyloid A concentration from 286.8 to 498.8 µg/mL, but did not affect other markers of inflammation including haptoglobin, fibrinogen, serum copper, or white blood cells. These results suggest that grain-induced SARA in mid lactation dairy cows increases the lysis of gram-negative bacteria and activates an inflammatory response.
Key Words: subacute ruminal acidosis • lipopolysaccharide • serum amyloid A • haptoglobin
This article has been cited by other articles:
|
|
 |
|
  Q. Zebeli, J. Dijkstra, M. Tafaj, H. Steingass, B. N. Ametaj, and W. Drochner Modeling the Adequacy of Dietary Fiber in Dairy Cows Based on the Responses of Ruminal pH and Milk Fat Production to Composition of the Diet J Dairy Sci, May 1, 2008; 91(5): 2046 - 2066. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. T. M. van Knegsel, G. de Vries Reilingh, S. Meulenberg, H. van den Brand, J. Dijkstra, B. Kemp, and H. K. Parmentier Natural Antibodies Related to Energy Balance in Early Lactation Dairy Cows J Dairy Sci, December 1, 2007; 90(12): 5490 - 5498. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. G. V. Emmanuel, K. L. Madsen, T. A. Churchill, S. M. Dunn, and B. N. Ametaj Acidosis and Lipopolysaccharide from Escherichia coli B:055 Cause Hyperpermeability of Rumen and Colon Tissues J Dairy Sci, December 1, 2007; 90(12): 5552 - 5557. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
