The impact of stress in domestic animals: roles of heat shock proteins and acute-phase proteins.

Stress is a term used to describe environmental stimuli that disrupt homeostasis. In response, animals activate a complex stress response that serves as a defense mechanism to restore balance and maintain physiological function. It impacts growth, reproductive performance, meat quality, animal welfare, and susceptibility to diseases. Heat shock proteins (HSPs) are abundant conserved proteins activated in response to various physiological and environmental stresses, such as heat shock, oxidative stress, heavy metals, ultraviolet radiation, and membrane perturbation Acute phase proteins (APPs) are a recognized method to quantify stressors and serve as reliable biomarkers of animal well-being. Although primarily synthesized in the liver, APPs can also be found in non-hepatic tissues and the bloodstream, reflecting the physiological response to stress. HSPs play a crucial role in the stress response mechanisms of cells, particularly in camels, which adapt to harsh environmental conditions. They help cells adapt by triggering the heat shock response (HSR), increasing the expression of stress-related enhancing homeostasis, and improving stress resistance. Transport stress, particularly in veterinary medicine, can cause organ damage, poor feed conversion ratios, and weight loss in pigs. HSPs detect changes in cellular redox state during stress, prompting other HSPs to normalize misfolded proteins and mitigate cellular stress. Understanding HSPs alterations under stress benefits the animal breeding industry, as animals rapidly synthesize HSPs as a self-protective mechanism. Serum amyloid A (SAA) is another major APP in vertebrates, with increased levels found following inflammation and non-inflammatory conditions. Studies have shown variable results in haptoglobin (Hp) levels in response to various stressors in cattle and other livestock. Understanding the complex responses of different species, stressors, and physiological responses in various animal species is crucial for accurate diagnosis.