In vitro efficacy of absorbents to trap intrinsically generated lipopolysaccharides in rumen fluid of dairy cows

Abstract

Laminitis is a common health problem in dairy cows in Thailand nowadays. In order to maintain high production, dairy cows need to be fed with a diet high in grain and low in forage. Consequently, the diet contains a high amount of rapid fermentable carbohydrates and insufficient fiber. This results in the production of a large quantity of volatile fatty acids, and causes a depression on the rumen pH and associated with rumen acidosis. (Kleen et al, 2009). Subacute ruminal acidosis (SARA), the condition were the rumen pH<5.6 for at least 180 min/d (Gozho et al., 2005), is suggested to play an important role in the cascade. It has been suggested that the pathogenic mechanism of laminitis may involve the activation of systemic inflammatory responses due to the lysis of gram-negative bacteria. Rumen pH depression during SARA increases free LPS concentration of the rumen (Emmanuel et al., 2008; Gozho et al., 2007) and may result in the transfer of LPS from the gut into blood circulation, and activation of an inflammatory response (Khafipour et al., 2009). Thus, materials that can bind LPS in the rumen and can prevent the transfer of endotoxin (LPS) to the blood are potentially of interest to the prevention of laminitis. It is know that montmorillonite have binding affinity for LPS (Pilachai et al., 2010, unpublished data). This trial was conducted to evaluate the efficacy of three adsorbents; montmorillonite, hydrate sodium calcium aluminosilicate (HSCAS) and modified HSCAS, to trap intrinsically generate lipopolysaccharides (LPS) in rumen fluid collected from SARA induced cows. In vitro, we added the three absorbents at three levels (0, 0.5 and 1% (w/v) to the rumen fluid from SARA cows and measured the LPS concentration.

It appear that the sequestering agents tested here had no significant absorbing effect on the LPS in the rumen fluid of the SARA induced cows.