%0 Journal Article
%T Selenium-Dependent Regulation of Oxidative Stress and Immunity in Periparturient Dairy Cattle
%A Lorraine M. Sordillo
%J Veterinary Medicine International
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/154045
%X Uncontrolled or impaired immune and inflammatory responses in periparturient dairy cows are associated with increased incidence and severity of infectious diseases. The progressive development of oxidative stress during the transition from late gestation to peak lactation is thought to be a significant underlying factor leading to dysfunctional immune cell responses. Certain trace minerals, such as selenium (Se), can ameliorate oxidative stress and reduce the severity of several economically important diseases in dairy cattle including mastitis and metritis. Many of the health benefits of Se can be attributed to the antioxidant functions of selenoproteins. Changes in selenoprotein activity as a consequence of Se nutritional status can directly alter a number of critical cellular functions involved in the inflammatory response. A better understanding of how Se can optimize immune cell responses may facilitate the design of nutritional regimes that will reduce health disorders during the periparturient period. 1. Introduction Dairy cattle have an increased susceptibility to infectious diseases during the periparturient period [1]. A major contributing factor to increased health disorders is thought to be due to dysfunctional bovine immune responses [2, 3]. Indeed, uncontrolled or impaired inflammatory responses are a major contributing factor to several economically important diseases including metritis, laminitis, and mastitis [4]. Increased health problems around the time of calving are especially problematic because they may greatly impact the productive efficiency of dairy cattle in the ensuing lactation. Therefore, it is not surprising that considerable research efforts have focused on defining factors that may contribute to immune dysfunction during this critical period in the production cycle of dairy cows [4¨C6]. The progressive development of oxidative stress in transition dairy cattle is thought to be a significant underlying factor leading to dysfunctional inflammatory responses [6, 7]. Certain trace minerals, such as Se, can be effective in reducing oxidative stress and the severity of several proinflammatory-based dairy cattle diseases such as mastitis and metritis [6, 8]. Many of the antioxidant functions of Se are mediated through the reducing capacity of selenoproteins including the glutathione peroxidase (GPX) and thioredoxin reductase (TrxR) families. Selenoproteins also can regulate intercellular signaling pathways that orchestrate the expression of mediators that serve to optimize the inflammatory response and restore immune
%U http://www.hindawi.com/journals/vmi/2013/154045/