The objective of this research was to design and test a novel conductive cooling system for controlling heat stress in lactating dairy cows by circulating chilled water through modified DCC waterbeds (Dual Chamber Cow Waterbeds). The system was tested to determine (1) the heat flux between the cooled waterbeds and the cows; (2) the production benefit to heat-stressed dairy cows; (3) the sensitivity of moisture accumulation and heat flux to type and thickness of bedding; and (4) the potential economic benefit. The calculated heat flux of the system was 439 W/m2 when the temperature of the circulating water in the waterbeds was 4.5oC and was 382 W/m2 when the circulating water temperature was 10.0oC. This was for live cows and about 1 cm of sawdust bedding. This amount of heat flux is significant compared to the amount of metabolic heat a lactating cow must lose. Conductively cooling the cows with 4.5°C water decreased core body temperature by 1.0°C (p

Animals and environment; Homeostasis of animals; Homeothermy of animals; Psychrometrics; Heat and mass transer as affected by ambient temperature; Humidity and its effect on animals; Convective heat loss from animals; Radiant heat loss from animals; Radiation protection in the hot climate; Poultry and their environment; Heat and vapor transmission in buildings; Heat and water vapor production in livestock and poultry structure; Air exchange in livestock and poultry buildings; Environmental control and the climate; Air flow patterns; Energy conservation principles; Appendix; Index.

Heat stress represents a significant cost to the dairy industry. To alleviate these loses, dairy producers have invested into designing and installing ventilation and cooling systems for their dairy cows. The design of dairy barns is usually (for new barns) based on the cooling requirements for the dairy cows, which vary significantly with breed and region. New systems are beginning to cool the cow itself, rather than the whole barn in order to increase efficiency. The present work evaluates two dairy cow cooling systems: a positive pressure tube ventilation, using experimental data as computational modeling; and a conduction cooling heat exchanger using experimental data. Testing these systems at production scale is expensive and time consuming for producers. In order to alleviate these costs, computational fluid dynamic models can be used to estimate the systems performance before they are installed. However, there is a need to understand how accurately the cow should be represented within these models. Therefore this study evaluates six different cow analogs, three primitives (sphere, cylinder, rectangular prism) and three realistic (six-cylinder cow, low polygon cow, high polygon cow) geometries in order to compare and contrast their applicability in computational modeling. The study discusses the ability of computational fluid dynamics models to evaluate positive pressure tube ventilation. The ability of conduction cooling to maintain cows cool during high temperatures and humidity is discussed in detail. Furthermore, the different cow geometries are evaluated and suggestions as to when each is to be used are provided. The low polygon cow representation is then used to evaluate the animal occupied zone as porous media assumptions within the holding area of the barn.

Dr. Anjali Aggarwal is working as a Senior Scientist at National Dairy Research Institute, Karnal (India). She holds a PhD degree in Animal Physiology and is involved in research and teaching at post-graduate level. Her area of research work is stress and environmental physiology. She has more than 50 publications, two technical bulletins, four manuals and many book chapters to her credit. She has successfully guided many post-graduate and PhD students. Her major research accomplishments are on microclimatic modification for alleviation of heat and cold stress, mist and fan cooling systems for cows and buffaloes, and use of wallowing tank in buffaloes. Her work involves the use of technology of supplementing micronutrients during dry period and early lactation to crossbred and indigenous cows for alleviating metabolic and oxidative stress and improved health and productivity. Studies are also done in her lab on partitioning of heat loss from skin and pulmonary system of cattle and buffaloes as a result of exercise or exposure to heat stress. Dr. R.C. Upadhyay is working as Head, Dairy Cattle Physiology Division at National Dairy Research Institute, Karnal (India). He graduated in Veterinary Sciences and obtained his PhD degree in Animal Physiology. His area of recent research is climate change, stress, and environmental physiology. His major research accomplishment is on climate change impact assessment of milk production and growth in livestock. His work also involves studying methane conversion and emission factors for Indian livestock and use of IPCC methodology of methane inventory of Indian livestock. Heat shock protein-70 expression studies in cattle and buffaloes are also done in his lab. Draught animal power evaluation, fatigue assessment, work-rest cycle and work limiting factors form the highlights of his work. Studies on partitioning of heat loss from skin and pulmonary system of cattle and buffaloes and electrocardiographic studies in cattle, buffalo, sheep and goat are also undertaken in his lab. He has more than 75 research papers, four books and several book chapters to his credit. Technologies developed and research done by him include methodology of methane measurement: open and closed circuit for cattle and buffaloes; inventory of methane emission from livestock using IPCC methodology; livestock stress index: thermal stress measurement based on physiological functions; and draught power evaluation system and large animal treadmill system. He received training in Radio-nuclides in medicine at Australian School of Nuclear Technology, Lucas heights, NSW, Australia in 1985 and Use of radioisotopes in cardiovascular investigations at CSIRO, Prospect, NSW, Australia, during 1985-86. He has guided several post-graduate and PhD students. He is recipient of Hari Om Ashram Award-1990 (ICAR) for outstanding research in animal sciences.

Environmental stress is one of the most significant factors affecting livestock performance and health, and it is only expected to increase with effects of global warming. Environmental Physiology of Livestock brings together the latest research on environmental physiology, summarizing progress in the field and providing directions for future research. Recent developments in estimating heat stress loads are discussed, as well as key studies in metabolism, reproduction, and genetic expressions. Environmental Physiology of Livestock begins with a survey of current heat indexing tools, highlighting recent discoveries in animal physiology, changes in productivity levels, and new technologies available to better estimate stress response. Using this synopsis as a point of orientation, later chapters hone in on major effects of heat stress, including changing metabolic pathways and nutrient requirements, endocrine regulation of acclimation to environmental stress, and reduced reproductive performance. The text concludes with a thorough discussion of environmental effects on gene expressions, providing important insight for future breeding practices. Environmental Physiology of Livestock is a globally contributed volume and a key resource for animal science researchers, geneticists, and breeders.

Given the importance of livestock to the global economy, there is a substantial need for world-class reference material on the sustainable management of livestock in diverse eco-regions. With uncertain climates involving unpredictable extreme events (e.g., heat, drought, infectious disease), environmental stresses are becoming the most crucial factors affecting livestock productivity. By systematically and comprehensively addressing all aspects of environmental stresses and livestock productivity, this volume is a useful tool for understanding the various intricacies of stress physiology. With information and case studies collected and analyzed by professionals working in diversified ecological zones, this book explores the influence of the environment on livestock production across global biomes. The challenges the livestock industry faces in maintaining the delicate balance between animal welfare and production are also highlighted.

Amidst escalating production scales, sustainability imperatives, and heightened awareness of animal welfare with increasingly extreme weather conditions, heat stress in livestock has emerged as a paramount concern for the U.S. dairy industry. Conventional cross- and tunnel-ventilation systems, which have become the standard mechanical system for cow cooling and barn ventilation in large dairy barn facilities, might no longer meet the requirements per cow, given the expanding numbers of cows accommodated within single facilities. This dissertation proposed a series of elements that all pertain to one overarching goal of developing an intelligent animal-centric ventilation system design and control that could address some of the identified concerns with mechanical ventilation in large-scale dairy barns while meeting animal-specific cooling requirements. Solving this problem requires many different interdisciplinary efforts to perfect. However, the studies presented in this dissertation aim to serve as a foundation for future studies. Due to the nature of interdisciplinary studies, many of the presented solutions contain technical knowledge from various disciplines (e.g. Machine Learning, Computational Fluid Dynamics, and Internet of Things).The two major components required for developing an effective animal-centric ventilation system are a sound method to retrieve animal-based heat stress index and an appropriate targeted cooling ventilation design that can efficiently be controlled using that direct heat stress index. Chapter Two delves into the real-time monitoring of dairy cow heat stress by employing an Internet of Things-infused rechargeable ear tag. This wireless device tracks the subcutaneous ear temperature, offering a minimally invasive proxy to gauge core body temperatures. Chapter Four describes the design optimization and cooling performance evaluation of PPPV. Design parameter optimization and performance prediction using CFD are crucial, especially in a newly proposed system without a direct predecessor. Lastly, Chapter Three delineates the conception of a machine-learning-augmented computational fluid dynamics (CFD-ML) simulator. This CFD-ML model, which can "simulate" heat and mass transfer phenomena in a dairy barn with much less required computational cost, can be a blueprint for smart simulation tools that can eventually support and aid in ventilation design processes, as described in Chapter Three. In the future, these individual efforts should come together to attain the ultimate goal of developing a smarter, animal-centric dairy barn ventilation system.