About this Research Topic
Climate change and global warming are among the most critical challenges that the livestock industry will face in the future. As reported by the Intergovernmental Panel on Climate Change (2014), the rise in global average surface temperature may be between 0.3°C and 4.8°C by the year 2100, with a predicted increase in the frequency and intensity of heat waves. As a result, there are serious concerns regarding livestock production losses and animal welfare. Genetic selection programs adopted across livestock species continue to increase animal performance but coincide with a parallel declining tolerance to high temperatures, accompanied by an increased susceptibility to infectious diseases. Heat stress is responsible for alterations in livestock physiology by activating compensatory mechanisms to cope with various environmental conditions and maintain vital functions. This is particularly true during periods of physiological adaptation in farm animals, such as the periparturient period, weaning, and the onset of egg production in layer hens. Generally, these critical periods increase the incidence and severity of both metabolic and infectious diseases.
Immunosuppression and uncontrolled inflammation are major contributing factors to increased health disorders via alterations in (i) the secretion of cytokines and other mediators such as IL-6, Il-10, IL-1βbeta, TNF-α, interferon-γ, TGF-β, CCL2, and heat shock proteins; (ii) the activation of receptors such as IL-1RA and TLR4 and (iii) the specificity of both innate and adaptive immune responses. However, the precise mechanisms of immune system responses to stress remain poorly understood. This is primarily because stress responsiveness is influenced by the complexity of both the immune and stress systems, their interactions, and other characteristics of farm animals (i.e., species, age, genetics). The nutritional and metabolic status of livestock are key factors that regulate immune cell functions. For example, both dietary factors and heat stress can modify neutrophil function and migration, as well as of T helper cell populations in livestock animals.
Discordant effects of climate change on livestock immune responses are evident in the literature; some studies have clearly demonstrated a suppressive effect of heat stress on the immune competence of the host, leading to enhanced susceptibility to disease. In contrast, other studies, particularly those evaluating the direct effects of temperature on immune cell function, have shown an enhancement or no effects of heat stress on livestock immune responses. Climate change also has an indirect impact on host resistance to infections by the influence on vector-borne disease distribution.
This Research Topic intends to provide a comprehensive overview of the current knowledge of immune system responses in livestock as a result of alterations in climate. We welcome the submission of Original Research, Review, Mini-Review, Methods and Perspective articles on the immunology of livestock under climate change that cover, but are not limited to, the following sub-topics:
1. Changes in livestock pathogens and vectors in response to climate change; for example, the increasing geographic range of arthropods, and its effects on corresponding host immune responses.
2. Genetic or physiological interactions between stress responses and the immune system.
3. Alterations in the functions of the innate and adaptive immune system of livestock animals at higher temperatures.
4. Opportunities for genetic selection to address immunity challenges in the face of heat stress.
5. Impact of heat stress management strategies - such as cooling, bioactive feed ingredient use, or acclimation strategies - on innate and adaptive immunity in livestock.
6. Sustainability challenges and solutions related to disease burden for livestock production in the face of a changing climate.
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