|Nienaber, John - Jack|
|Yen, Jong tseng|
Submitted to: Book Chapter
Publication Type: Other
Publication Acceptance Date: 6/19/2007
Publication Date: 12/1/2009
Citation: Nienaber, J.A., DeShazer, J., Xin, H., Hillman, P., Yen, J., Ferrell, C.L. 2009. Chapter 4: Measuring Energetics of Biological Processes. In: DeShazer, J.A., ed. Livestock Energetics and Thermal Environmental Management. St. Joseph, MI:American Society of Agricultural and Biological Engineers. p. 73-112. Interpretive Summary:
Technical Abstract: Measurement of the energetics of biological processes is the key component in understanding the thermodynamic responses of homoeothermic animals to the environment. For these animals to achieve body temperature control, they must adapt to thermal-environmental conditions and variations caused by weather, climate, vegetation, topography, and shelters. Physiological adaptation is the capacity and process of adjustment of the animal to itself, to other living material, and to its external physical environment. Genetic adaptation refers to the selection and heritability of characteristics for a particular environment or climatic region. A long-term adaptive physiological adjustment is referred to as acclimatization. Since adaptation of the animal to its thermal environment requires regulation of body temperature, measurement of that adaptation through animal energetics provides an indicator of the extent and energetic cost of adaptation. This chapter summarizes numerous methods to evaluate the energetics of livestock production. An understanding of these responses allows for informed management decisions necessary for both production and well-being issues. However, limitations exist in the understanding. As production practices continue to change and livestock genetic improvements continue for all species, this database of known responses will need to be re-evaluated to incorporate expected energetic changes. Moisture production of livestock and ancillary moisture loads within buildings is an example of that limited knowledge base. Dramatic genetic improvements and numerous management practices, both of which impact building moisture loads, have occurred within livestock production systems but have not been fully tested. As production system designs move forward, available data will provide a basis for estimating loads, but future designers will be required to devise methods to critically evaluate the information available and to fill knowledge gaps resulting from limited available data.