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Encyclopedia Of Animal Science - A

Từ điển khoa học động vật vần A | Animal Science edited by Wilson G. Pond Alan w Bell Adaptation and Stress Animal State of Being Stanley E. Curtis University of Illinois Urbana Illinois U.S.A. INTRODUCTION Sound animal husbandry depends on application of scientific knowledge of many aspects of the biology of the animals we keep. Environmental aspects of animal care are based on application of principles of animal ecology in design operation troubleshooting and correcting deficiencies. They are crucial to both economical animal production and responsible animal stewardship. ADAPTATION Any environment has factors that threaten to overwhelm its inhabitants. Animals are driven to adapt to their environments and thereby remain fit. Adaptation is an animal s adjustment to its environment especially a nonideal one so its life and species can continue. Realistic Expectations Animals sometimes fail to adapt they experience stresses of various kinds. So they may feel well fair or ill described later . We should expect an animal to experience well-being mostly fair-being sometimes ill-being once in a while. When an animal shows signs of failing to adapt correcting the problem may not be easy. Animal Responses An animal s environment consists of a complex of elements each of which varies over time across space in intensity. Most combine in additive fashion as they affect an animal. Internal steady state An animal normally maintains steady states over time in the various aspects of its internal environment. This mechanism homeokinesis is the general basis of environmental adaptation. When an animal perceives a threat or actual shift in some internal or external feature it reacts to preempt or counteract that change. It attempts to keep an internal steady state and thereby to survive and thrive. The essence of an animal s homeokinetic mechanisms is similar to that of a home s simple thermostat a negative-feedback control loop. Coping An environmental adaptation refers to any behavioral functional immune or .