Factors affecting mammary gland immunity and mastitis susceptibility

College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
Livestock Production Science (Impact Factor: 1.17). 05/2005; 98:89-99. DOI: 10.1016/j.livprodsci.2005.10.017


Dairy cattle are more susceptible to mastitis during the periparturient period. It is well established that the incidence of mastitis with respect to lactation stage are directly related to changes in the composition, magnitude, and efficiency of the mammary gland defense system. There exist numerous genetic, physiological, and environmental factors that can compromise host defense mechanisms during the functional transitions of the mammary gland. For example, physiological stresses associated with rapid differentiation of secretory parenchyma, intense mammary gland growth, and the onset of milk synthesis and secretion are accompanied by a high energy demand and an increased oxygen requirement. This increased oxygen demand augments the production of oxygen-derived reactants, collectively termed reactive oxygen species (ROS). The excessive accumulation of ROS can lead to a condition referred to as oxidant stress that plays a central role in mediating uncontrolled inflammatory responses and causing tissue injury. While the last two decades have seen major progress in understanding the bovine mammary gland defense system and its function in preventing disease, diminished host defenses and increased susceptibility to mastitis continue to be a problem for dairy cattle during transition periods. This paper provides an overview of mammary immunobiology and describes those factors known to influence important mammary gland defenses during the periparturient period.

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Available from: Lorraine M Sordillo,
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    • "On the other hand, B lymphocytes are responsible for production of antibodies (immunoglobulins) against specific bacterial pathogens. Among immunoglobulins, IgG 1 , IgG 2 and IgM facilitate phagocytosis by neutrophils and macrophages acting as opsonins, whereas, IgA cause the agglutination of pathogens preventing their spread within the mammary gland (Sordillo, 2005). "
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    ABSTRACT: Bacterial mastitis is a significant welfare and financial problem in sheep flocks. This paper reviews the recently published literature, including publications that highlight the significance and virulence factors of the causal agents, especially Staphylococcus aureus and Mannheimia haemolytica, the primary causes of the disease. Research has also contributed to the understanding of risk factors, including genetic susceptibility of animals to infections, supporting future strategies for sustainable disease control. Pathogenetic mechanisms, including the role of the local defenses in the teat, have also been described and can assist formulation of strategies that induce local immune responses in the teat of ewes. Further to well-established diagnostic techniques, i.e., bacteriological tests and somatic cell counting, advanced methodologies, e.g., proteomics technologies, will likely contribute to more rapid and accurate diagnostics, in turn enhancing mastitis control efforts. Copyright © 2015 Elsevier B.V. All rights reserved.
    Veterinary Microbiology 07/2015; DOI:10.1016/j.vetmic.2015.07.009 · 2.51 Impact Factor
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    • "MG immunity depends on the complex combination and coordination of nonspecific and specific protective elements, including the anatomical features of the gland as well as cellular and humoral defence components [5]. Nevertheless, MG immune defence varies over different stages of lactation in dairy animals and is typically depressed with exposure to stress and around drying-off and parturition, thus increasing susceptibility to mastitis [6] [7]. However, a considerable body of evidence has accumulated suggesting that mastitis is a multifactorial complex, and several management and environmental factors must interact to increase host exposure to mastitis pathogens, reduce the natural resistance of animals to disease, or aid pathogens in gaining entrance to the MG environment to cause infection [2] [4] "
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    ABSTRACT: The health of dairy animals, particularly the milk-producing mammary glands, is essential to the dairy industry because of the crucial hygienic and economic aspects of ensuring production of high quality milk. Due to its high prevalence, mastitis is considered the most important threat to dairy industry, due to its impacts on animal health and milk production and thus on economic benefits. The MG is protected by several defence mechanisms that prevent microbial penetration and surveillance. However, several factors can attenuate the host immune response (IR), and the possession of various virulence and resistance factors by different mastitis-causing microorganisms greatly limits immune defences and promotes establishment of intramammary infections (IMIs). A comprehensive understanding of MG immunity in both healthy and inflammatory conditions will be an important key to understand the nature of IMIs caused by specific pathogens and greatly contributes to the development of effective control methods and appropriate detection techniques. Consequently, this review aims to provide a detailed overview of antimicrobial defences in the MG under healthy and inflammatory conditions. In this sense, we will focus on pathogen-dependent variations in IRs mounted by the host during IMI and discuss the potential ramifications of these variations.
    • "It is well known that changes in the mammary gland start during the last term of pregnancy, with colostrogenesis beginning several weeks before calving (Brandon et al., 1971). These changes imply an increased production of ROS and cytokines in the udder as lactation commences, simultaneously with an increase of the risk of suffering an intramammary infection (Sordillo, 2005; Baldi et al., 2008; Spears and Weiss, 2008), and it is just at this time, when nutrition has a major impact on udder health (Baldi et al., 2008). "
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    ABSTRACT: Dairy cows are especially vulnerable to health disorders during the transition period, when they shift from late pregnancy to the onset of lactation. Diseases at this stage affect not only the animals' well-being, but also cause a major economic impact in dairy farms, because apart from treatment costs, affected cows will not reach their peak milk-producing capacity. The overproduction of reactive oxygen species (ROS) leads to oxidative stress, which has been identified as an underlying factor of dysfunctional inflammatory responses. Supplementation with vitamins and trace elements attempts to minimize the harmful consequences of excessive ROS production, thereby trying to improve animals' health status and to reduce disease incidence. However, results regarding the effects of supplementing antioxidants on dairy cows' health and performance have been inconsistent, because in most cases, the antioxidant potential of the animals was not assessed beforehand and the nutritional strategy planned accordingly. Therefore, reviewing the physiological and harmful effects of ROS production, along with the different options available for assessing the redox balance in dairy cattle and some of the key findings of different supplementation trials, could bring one step forward the on-farm application of determinations of oxidative status for establishing nutritional strategies early enough in the dry period that could improve transition cow health. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.
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