부산대학교 도서관

Acute phase and inflammatory responses are triggered by a variety of intrinsic and extrinsic stressors that come at a cost through suppressing the normal function of tissues and organs of domestic animals. Recently, with growing attention placed on global warming and animal welfare, there has been an increased interest in improving our understanding of the relationships between different classes of stress, the expression of acute phase proteins (APPs), the stress-related endocrine system and immunomodulation. Immune function is compromised by all forms of stress including poor nutrition, weaning, extreme thermal conditions, injury and infection in calves. Proinflammatory cytokines, APPs and hormones of the hypothalamic-pituitary adrenal axis as well as the composition of immune cells can all be characterised in culture supernatants and peripheral blood. APPs have been used as biomarkers for the stress status of ruminants both experimentally and in field studies. Therefore detailed studies of the mechanisms of action of these APPs and their interactions in ameliorating different stress responses are warranted. The focus of this review is on the aetiology of the responses in calves under severe stress and its impact on growth and immune status. Possible strategies to alleviate this condition including the role of specific feed additives are presented. Accurate characterisation of responses to specific stressors encountered by production animals requires an analysis of key indicators of endocrine, immune and cellular adjustments as the animal strives to sustain homeostasis. Acute phase proteins can provide an important initial indication of the nature of a stressor; when combined with cytokine and cellular immune analyses, the severity of the consequences of a specific stress can be diagnosed. Responses to physical, infectious, metabolic and psychological stressors encountered by calves during their development have been reviewed herein. No single class of molecules or cells has been identified as a definitive diagnostic for any of these stressors, but rather a multi-factorial analysis is required. [ABSTRACT FROM AUTHOR]