Effects of Heat Stress and Body Weight on the Performance, Health, Survival, and Physiology of Holstein Dairy Cattle
Effects of Heat Stress and Body Weight on the Performance, Health, Survival, and Physiology of Holstein Dairy Cattle

Author: Longfei Han

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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Improving heat-stressed animal health and survival through management, nutrition, and genetics is critical to profitability and sustainability on a dairy farm. The objectives of this dissertation were to estimate genetic parameters of heat tolerance in dairy cattle for the health and survival traits; to investigate the long-term impact of heifer development; and to examine the potential role of ghrelin in thermoregulation during heat stress. Five experiments were conducted and summarized. The first experiment investigated the effect of heifer development (measured as body weight at first calving, BWFC) on milk production and survival. First lactation 305-d milk yield and 24-month milk yield were analyzed with a linear model. Survival analysis was performed to estimate the impact of BWFC on survival. Heifers in the top 60% of body weight at first calving had significantly higher first lactation 305-d milk yield than lighter heifers, but no relationship of BWFC and first lactation 305-d milk yield existed within the top 60%. Relationships between BWFC and 24-month milk yield were not significant. Heifers with higher BWFC lost significantly more body weight in early lactation. While BWFC was a significant predictor of first lactation 305-d milk yield, it accounted for 3% of variation, suggesting that BWFC is not a primary contributor to variation in milk yield. Compared to the lightest heifers, heaviest heifers were 49% more likely to be culled at any given time. These data indicated that, among heifers managed similarly, heavier heifers produced more milk in first lactation than lighter heifers, but lost more BW, faced a higher risk of being culled, and did not produce more milk long-term. The second experiment examined 1), the effect of climatic conditions at birth on organic calf stayability to 365 d of age (STAY) and respiratory disease (RESP) by 365 d of age, and 2), the genetic parameters of organic Holstein calf heat tolerance (HT) for STAY and RESP. HT was defined as the rate of change in STAY and RESP when a calf was born under heat stress. The final dataset included 77,090 calves from 16 USDA certified organic farms and included 35,520 Holsteins for genetic analyses. Phenotypic data were combined with climatic data obtained from local weather stations based on the zip code. Phenotypic analyses were performed with a model that included THI, breed, diurnal THI variation (daily maximum THI -- daily minimum THI; DTV), contemporary group, breed, and genetic effects. Estimated breeding values were calculated for Holstein sires with more than 10 daughters in the dataset. By 365 d of age, 80% of the calves stayed in the herd, and 7% of the calves recorded at least one RESP. Calf STAY decreased and RESP increased when calves were born in THI over 65. The additive genetic HT effect was significant for STAY but not RESP. The heritability for STAY and RESP were 0.100 and 0.025, respectively. In conclusion, calf STAY, RESP, and HT for STAY were heritable in organic herds and can be improved through genetic selection. The third experiment investigated the genetic and environmental effect of heat stress at calving on organic cow health and survival. Health trait were mastitis, reproductive disease, disease during the transition period (TRAN); and stayability to 30 DIM (1 = stayed in the herd, 0 = culled or died by 30 DIM; STAY30). The final dataset included 83,394 lactations from 40,712 cows of 6 different breeds of which Holstein (32,007 lactations, 15,938 cows) were most frequent and were used for genetic analysis. Weather condition at calving was defined as cool (average THI

Heat Stress and Animal Productivity
Heat Stress and Animal Productivity

Author: Anjali Aggarwal

Publisher: Springer Science & Business Media

Published: 2012-12-30

Total Pages: 200

ISBN-13: 813220879X

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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.

Lactation and the Mammary Gland
Lactation and the Mammary Gland

Author: R. Michael Akers

Publisher: John Wiley & Sons

Published: 2016-02-10

Total Pages: 291

ISBN-13: 1119279674

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Michael Akers provides the basics for understanding mammary development and lactation and conveys the critical regulatory events in lactation. This text willl prove to be an invaluable overview of mamorary development and lactation for undergraduates and graduates studying lactation, new researchers, and as a review for established scientists. Additionally, the book will be an important resource for professionals in the animal and dairy industry and for those in other scientific disciplines such as food chemistry, cell biology, and endocrinology whose work is closely tied to mammary gland development and function. Lactation and the Mammary Gland covers growth and development of the mammary gland including comparisons between species. It imparts and emphasizes the critical nature of mammary growth and the onset of lactation at the time of parturition. Special emphasis is given to the endocrine and growth factor regulation of both mammogenesis and lactogenesis. A thorough discussion of the role of growth hormone in development and maintenance of lactation or galactopoiesis adds to this book's value as a text and reference. The author reviews the presence of hormones, growth factors, and other bioactive compounds in milk and mammary secretions as well as the potential for use of the mammary gland as a bioreactor in the pharmaceutical industry. A description of the nutritional and management factors in milk production round out the book's comprehensive coverage.

Heat Stress in Sport and Exercise
Heat Stress in Sport and Exercise

Author: Julien D. Périard

Publisher: Springer

Published: 2019-03-06

Total Pages: 294

ISBN-13: 3319935151

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The book is designed to provide a flowing description of the physiology of heat stress, the illnesses associated with heat exposure, recommendations on optimising health and performance, and an examination of Olympic sports played in potentially hot environmental conditions. In the first section the book examines how heat stress effects performance by outlining the basics of thermoregulation and how these responses impact on cardiovascular, central nervous system, and skeletal muscle function. It also outlines the pathophysiology and treatment of exertional heat illness, as well as the role of hydration status during exercise in the heat. Thereafter, countermeasures (e.g. cooling and heat acclimation) are covered and an explanation as to how they may aid in decreasing the incidence of heat illness and minimise the impairment in performance is provided. A novel and particular feature of the book is its inclusion of sport-specific chapters in which the influence of heat stress on performance and health is described, as well as strategies and policies adopted by the governing bodies in trying to offset the deleterious role of thermal strain. Given the breadth and scope of the sections, the book will be a reference guide for clinicians, practitioners, coaches, athletes, researchers, and students.

Adaptation of Domestic Animals
Adaptation of Domestic Animals

Author: Elsayed Saad Eldin Hafez

Publisher:

Published: 1968

Total Pages: 458

ISBN-13:

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Ecological and bioclimatological aspects. Basic physiological mechanisms. Adaptation to specific environments. Species-specific adaptations. Techniques of investigations.

Climate Change Impact on Livestock: Adaptation and Mitigation
Climate Change Impact on Livestock: Adaptation and Mitigation

Author: Veerasamy Sejian

Publisher: Springer

Published: 2015-03-31

Total Pages: 532

ISBN-13: 8132222652

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This volume addresses in detail both livestock’s role in climate change and the impacts of climate change on livestock production and reproduction. Apart from these cardinal principles of climate change and livestock production, this volume also examines the various strategies used to mitigate livestock-related GHG emissions, and those which can reduce the impacts of climate change on livestock production and reproduction. Presenting information and case studies collected and analyzed by professionals working in diversified ecological zones, the book explores the influence of climate change on livestock production across the globe. The most significant feature of this book is that it addresses in detail the different adaptation strategies and identifies targets for different stakeholders in connection with climate change and livestock production. Further, it puts forward development plans that will allow the livestock industries to cope with current climate changes and strategies that will mitigate the effects by 2025. Lastly, it provides researchers and policymakers several researchable priorities to help develop economically viable solutions for livestock production with less GHG emissions, promoting a cleaner environment in which human beings and livestock can live in harmony without adverse effects on productivity. Given that livestock production systems are sensitive to climate change and at the same are themselves a contributor to the phenomenon, climate change has the potential to pose an increasingly formidable challenge to the development of the livestock sector. However, there is a dearth of scientific information on adapting livestock production to the changing climate; as such, well-founded reference material on sustaining livestock production systems under the changing climate scenarios in different agro-ecological zones of the world is essential. By methodically and extensively addressing all aspects of climate change and livestock production, this volume offers a valuable tool for understanding the hidden intricacies of climatic stress and its influence on livestock production.

Environmental Physiology of Livestock
Environmental Physiology of Livestock

Author: R. J. Collier

Publisher: John Wiley & Sons

Published: 2012-02-07

Total Pages: 360

ISBN-13: 0813811767

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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.

Environmental Stress and Amelioration in Livestock Production
Environmental Stress and Amelioration in Livestock Production

Author: Veerasamy Sejian

Publisher: Springer Science & Business Media

Published: 2012-06-05

Total Pages: 577

ISBN-13: 3642292054

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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.

The Effects of Heat Stress and Dietary Organic Acid and Pure Botanical Supplementation on Growth and Lactation in Dairy Cattle
The Effects of Heat Stress and Dietary Organic Acid and Pure Botanical Supplementation on Growth and Lactation in Dairy Cattle

Author: Ananda Barbara Portela Fontoura

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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Heat stress (HS) compromises the gastrointestinal barrier and leads to inflammation in non-ruminants. However, it is unclear whether exposure to environmental conditions that cause HS enhances gastrointestinal permeability with compromised growth and milk production in dairy cattle. Developing nutritional strategies to manage HS in cattle are of importance to the dairy industry. Dietary supplementation of organic acid and pure botanicals (OA/PB) has been shown to improve growth performance by enhancing gastrointestinal health in swine and poultry species. Because the role of dietary OA/PB supplementation in ruminants had not received prior attention, our objectives were to 1) evaluate the effects of HS and dietary OA/PB supplementation on growth in dairy calves, and 2) evaluate the effects of HS and dietary OA/PB supplementation on gastrointestinal permeability and milk production in mid-lactating dairy cows. For study 1, sixty-two weaned heifer and bull calves (62 ± 2 d; 91 ± 10.9 kg) were randomly assigned to one of five groups (n = 11 to 14/group): thermoneutral conditions (TN-Con), HS conditions (HS-Con), TN conditions and pair-fed to HS-Con (TN-PF), HS with low-dose OA/PB (75 mg/kg of body weight [BW]; HS-Low), or HS with high-dose OA/PB (150 mg/kg of BW; HS-High). After a 7-d acclimation period, calves were exposed to TN or HS for a period of 19 d. Blood samples were collected and growth performance was evaluated. We observed that HS-Con calves had reduced growth compared to TN-Con and TN-PF. Regarding dietary OA/PB supplementation, HS-Low partially restored dry matter intake (DMI) without modifying growth performance. Thus, we conclude that dietary OA/PB supplementation does not improve growth performance in heat-stressed calves. For study 2, forty-six multiparous lactating dairy cows (208 ± 4.65 d in milk; 3.0 ± 0.42 lactation; and 39.2 ± 0.26 kg of milk yield) were randomly assigned to one of four groups (n = 10 to 12/group): TN-Con, HS-Con, TN-PF, or HS supplemented with OA/PB (75 mg/kg of BW; HS-OAPB). Cows acclimated in TN for 7-d, and then exposed to HS or remained in TN for 14-d. Blood and milk samples were collected. Changes in milk production and gastrointestinal permeability were evaluated. We observed that HS-Con cows had reduced DMI, energy-corrected milk yield, and milk protein and lactose yields compared to TN-Con, TN-PF and HS-OAPB cows. Milk- and plasma-urea nitrogen were reduced in HS-OAPB compared to HS-Con cows. Gastrointestinal permeability was greater in HS-Con, relative to TN-Con or TN-PF. We conclude that HS increased gastrointestinal permeability and that OA/PB feeding partially restores lactation performance by increasing DMI and improving intestinal barrier, and thereby enhancing milk yield and nitrogen efficiency.