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Research in Veterinary Science xxx (2012) xxx–xxx

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Research in Veterinary Science
journal homepage: www.elsevier.com/locate/rvsc

Interplay between rumen digestive disorders and diet-induced inflammation in dairy cattle
Q. Zebeli a,c,⇑, B.U. Metzler-Zebeli b,c
a

Institute of Animal Nutrition, Department for Farm Animals and VeterinaryPublic Health, Vetmeduni Vienna, Veterinaerplatz 1, 1210 Vienna, Austria Clinic for Swine, Department for Farm Animals and Veterinary Public Health, Vetmeduni Vienna, Veterinaerplatz 1, 1210 Vienna, Austria c Research Cluster ‘‘Animal Gut Health’’, Vetmeduni Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
b

a r t i c l e

i n f o

a b s t r a c t
In this review, an overview is providedon the current achievements regarding the interplay between rumen digestive disorders and diet-induced inflammation in dairy cattle. It starts with a review of factors favoring the disturbances in the rumen metabolism, which culminate with development of sub-acute rumen acidosis (SARA). The latter digestive disorder is often linked to greater metabolic stress of gastrointestinal (GI) microbiota andlowered fiber digestion, as well as with disruption of the barrier functions of the GI epithelia, which open the route of deleterious molecules to translocate from the GI lumen into the portal system. A model is suggested to illustrate the mechanisms of the involvement of digestive disorders in the disruption of the host’s inner homeostasis leading to activation of acute phase response (APR). Thelatter is part of multifaceted innate immune and metabolic responses of the host. According to this model, endotoxin, its toxicity, and other metabolic compounds of microbial origin are regarded as important immunogenic components of GI tract, which when favored by disruption of host barriers triggers a systemic APR. Although the activation of an APR is viewed as a protective reaction aiming toreestablish the disturbed homeostasis, the presence of inflammatory state over long periods might be associated with negative consequences for the host. The review concludes that prolonged systemic inflammation can: (1) cause significant changes in the energy and lipid metabolism in different body tissues, (2) lead to the development of refractory states associated with immune suppression and increasedsusceptibility to various diseases, and (3) artificially increase host’s requirements in energy and nutrients, lowering the efficiency of energy and feed use by the animal. The paper emphasizes the critical role that formulation of healthy diets plays for curbing down inflammation and enhancing metabolic health of dairy cows. Ó 2012 Elsevier Ltd. All rights reserved.

Article history: Received 16August 2011 Accepted 6 February 2012 Available online xxxx Keywords: Rumen disorders Systemic inflammation Rumen digestion Dairy cattle

1. Introduction Meeting energy and nutrient requirements of dairy cattle while avoiding digestive and systemic metabolic disturbances is critical to ensure that milk is produced from healthy animals in an efficient and cost-effective manner. The intensivemanagement systems of dairy cows encourage dietary inclusion of large amounts of cereal grains or easily degradable by-products to support high milk yields (Zebeli et al., 2010a). Although these feeding practices seem to increase milk production in a short-term, they do not cope with cattle’s digestive physiology (Zebeli and Ametaj, 2009). The most important consequence thereof is the impaired rumenecosystem, which is often perceived in form of a prolonged decline in ruminal pH to aci-

⇑ Corresponding author at: Institute of Animal Nutrition, Department for Farm Animals and Veterinary Public Health, Vetmeduni Vienna, Veterinaerplatz 1, 1210 Vienna, Austria. E-mail address: Qendrim.Zebeli@vetmeduni.ac.at (Q. Zebeli).
0034-5288/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved....