11 Impact of Heat Stress on Livestock and Mitigation Strategies to Improve Productivity and Well-Being.

Heat stress (HS) is a multi-factorial problem that negatively affects livestock health and productivity and is closely linked with animal welfare. While HS may not be harmful when animals are able to adapt, the physiological changes that occur to ensure survival may impede the efficient conversion of feed energy into animal products. This adaptive response can be variable and is often based on previous HS exposure, genetics, species and production stage. When the heat load becomes too great for adaptive responses to compensate, the subsequent strain response causes reduced productivity and well-being and, in severe cases, mortality. The effects of HS on livestock productivity are well documented and range from decreased feed intake and body weight gain, to reduced reproductive efficiency and altered carcass composition and meat quality. In addition, researchers are beginning to elucidate the effects of prenatal HS on postnatal livestock performance and welfare. As knowledge of the negative impacts of HS on livestock performance and welfare increases, so will the development of effective mitigation strategies to support maintenance of productivity during times of high thermal heat loads and preserve appropriate animal welfare standards.

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Review: Impacts of shade on cattle well-being in the beef supply chain

Journal of Animal Science ◽

10.1093/jas/skaa375 ◽

2020 ◽

Author(s):

Lily N Edwards-Callaway ◽

M Caitlin Cramer ◽

Caitlin N Cadaret ◽

Elizabeth J Bigler ◽

Terry E Engle ◽

...

Keyword(s):

Supply Chain ◽

Heat Stress ◽

Beef Cattle ◽

Production Systems ◽

Construction Materials ◽

Well Being ◽

Third Party ◽

Ambient Temperatures ◽

Stress Susceptibility ◽

The Impact

ABSTRACT Shade is a mechanism to reduce heat load providing cattle with an environment supportive of their welfare needs. Although heat stress has been extensively reviewed, researched, and addressed in dairy production systems, it has not been investigated in the same manner in the beef cattle supply chain. Like all animals, beef cattle are susceptible to heat stress if they are unable to dissipate heat during times of elevated ambient temperatures. There are many factors that impact heat stress susceptibility in beef cattle throughout the different supply chain sectors, many of which relate to the production system, i.e. availability of shade, microclimate of environment, and nutrition management. The results from studies evaluating the effects of shade on production and welfare are difficult to compare due to variation in structural design, construction materials used, height, shape, and area of shade provided. Additionally, depending on operation location, shade may or may not be beneficial during all times of the year, which can influence the decision to make shade a permanent part of management systems. Shade has been shown to lessen the physiologic response of cattle to heat stress. Shaded cattle exhibit lower respiration rates, body temperatures, and panting scores compared to un-shaded cattle in weather that increases the risk of heat stress. Results from studies investigating the provision of shade indicate that cattle seek shade in hot weather. The impact of shade on behavioral patterns is inconsistent in the current body of research, some studies indicating shade provision impacts behavior and other studies reporting no difference between shaded and un-shaded groups. Analysis of performance and carcass characteristics across feedlot studies demonstrated that shaded cattle had increased ADG, improved feed efficiency, HCW, and dressing percentage when compared to cattle without shade. Despite the documented benefits of shade, current industry statistics, although severely limited in scope, indicate low shade implementation rates in feedlots and data in other supply chain sectors do not exist. Industry guidelines and third party on-farm certification programs articulate the critical need for protection from extreme weather but are not consistent in providing specific recommendations and requirements. Future efforts should include: updated economic analyses of cost versus benefit of shade implementation, exploration of producer perspectives and needs relative to shade, consideration of shade impacts in the cow-calf and slaughter plant segments of the supply chain, and integration of indicators of affective (mental) state and preference in research studies to enhance the holistic assessment of cattle welfare.

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Radical Response: Effects of Heat Stress-Induced Oxidative Stress on Lipid Metabolism in the Avian Liver

Antioxidants ◽

10.3390/antiox10010035 ◽

2020 ◽

Vol 10 (1) ◽

pp. 35

Author(s):

Nima K. Emami ◽

Usuk Jung ◽

Brynn Voy ◽

Sami Dridi

Keyword(s):

Oxidative Stress ◽

Heat Stress ◽

Lipid Metabolism ◽

Egg Production ◽

Well Being ◽

Enzymatic Reactions ◽

Poultry Production ◽

Hepatic Lipid Metabolism ◽

Hepatic Lipid ◽

The Impact

Lipid metabolism in avian species places unique demands on the liver in comparison to most mammals. The avian liver synthesizes the vast majority of fatty acids that provide energy and support cell membrane synthesis throughout the bird. Egg production intensifies demands to the liver as hepatic lipids are needed to create the yolk. The enzymatic reactions that underlie de novo lipogenesis are energetically demanding and require a precise balance of vitamins and cofactors to proceed efficiently. External stressors such as overnutrition or nutrient deficiency can disrupt this balance and compromise the liver’s ability to support metabolic needs. Heat stress is an increasingly prevalent environmental factor that impairs lipid metabolism in the avian liver. The effects of heat stress-induced oxidative stress on hepatic lipid metabolism are of particular concern in modern commercial chickens due to the threat to global poultry production. Chickens are highly vulnerable to heat stress because of their limited capacity to dissipate heat, high metabolic activity, high internal body temperature, and narrow zone of thermal tolerance. Modern lines of both broiler (meat-type) and layer (egg-type) chickens are especially sensitive to heat stress because of the high rates of mitochondrial metabolism. While this oxidative metabolism supports growth and egg production, it also yields oxidative stress that can damage mitochondria, cellular membranes and proteins, making the birds more vulnerable to other stressors in the environment. Studies to date indicate that oxidative and heat stress interact to disrupt hepatic lipid metabolism and compromise performance and well-being in both broilers and layers. The purpose of this review is to summarize the impact of heat stress-induced oxidative stress on lipid metabolism in the avian liver. Recent advances that shed light on molecular mechanisms and potential nutritional/managerial strategies to counteract the negative effects of heat stress-induced oxidative stress to the avian liver are also integrated.

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143 Heat Stress Mitigation Strategies for Boars and Impact of Most Effective on Sperm Parameters.

Journal of Animal Science ◽

10.1093/jas/sky073.141 ◽

2018 ◽

Vol 96 (suppl_2) ◽

pp. 76-76

Author(s):

E D Grusenmeyer ◽

T J Safranski ◽

M C Lucy ◽

K Kerns ◽

P Sutovsky ◽

...

Keyword(s):

Heat Stress ◽

Mitigation Strategies ◽

Sperm Parameters

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Effect of Climate Change Associated Hazards on Agricultural Workers and Approaches for Assessing Heat Stress and Its Mitigation Strategies – Review of Some Research Significances

International Journal of Current Microbiology and Applied Sciences ◽

10.20546/ijcmas.2021.1002.325 ◽

2021 ◽

Vol 10 (2) ◽

pp. 2947-2975

Author(s):

Govinda Pal Thaneswer Patel ◽

Trishita Banik

Keyword(s):

Climate Change ◽

Heat Stress ◽

Mitigation Strategies ◽

Agricultural Workers

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Effects of increased ambient temperature and supplemental altrenogest prior to pregnancy establishment in gilts

Journal of Animal Science ◽

10.1093/jas/skac007 ◽

2022 ◽

Author(s):

Matthew R Romoser ◽

Katie L Bidne ◽

Lance H Baumgard ◽

Aileen F Keating ◽

Jason W Ross

Keyword(s):

Heat Stress ◽

Ovarian Tissue ◽

Economic Effects ◽

Mitigation Strategies ◽

Delayed Puberty ◽

Corpora Lutea ◽

Estrous Synchronization ◽

Conceptus Development ◽

Luteal Tissue ◽

Uterine Flushing

Abstract Heat stress (HS) mitigation strategies are critically needed to combat the substantial economic effects on animal agriculture. The manifestations of seasonal infertility include delayed puberty onset, reduced conception rates, decreased litter size, and increased wean to estrus interval. To assess the effects of HS during early gestation and evaluate a benefit of supplemental altrenogest (ALT) as a mitigation strategy, thirty crossbred post-pubertal gilts (157 ± 11 kg) were subjected to estrous synchronization via 14 d oral administration of ALT. Artificial insemination during estrus was performed and gilts were then placed into one of four treatment groups; heat stress (HS; 35 ± 1 οC for 12h/31.60 ± 1 οC for 12h) with (HSALT, n = 7) or without (HSCON, n = 7) 15 mg/d ALT supplementation or thermal neutral (TN; 20 ± 1 οC) conditions with (TNALT, n = 8) or without (TNCON, n = 8) 15 mg/d ALT supplementation until 12 d post-estrus (dpe). Administrating ALT occurred at 0600 h from 3-12 dpe and rectal temperatures (TR) and respiration rates (RR) were recorded. Blood was collected via jugular venipuncture on 0, 4, 8 and 12 dpe. Gilts were euthanized humanely at 12 dpe followed by collection of ovarian tissue, and uterine flushing for conceptus collection. In HS compared to TN gilts, RR and TR were increased (P < 0.01) but unaffected by ALT supplementation. Feed intake (FI) was reduced (P < 0.01) by HS but unaltered by ALT treatment. Corpora lutea (CL) weight was reduced (P < 0.01) in HSCON gilts when compared to TNCON and HSALT gilts despite progesterone (P4) concentrations in serum and luteal tissue not being affected by treatment (P ≥ 0.10). CL diameter was reduced (P ≤ 0.05) in HSALT gilts compared to other treatments. Interleukin-1β (IL1B) uterine flush concentration was not affected (P > 0.20) by environment or ALT supplementation, although moderate (P = 0.06) interaction between environment and ALT existed, as IL1B concentration in TNALT was increased (P = 0.03) compared to TNCON gilts. While environment did not affect conceptus development (P = 0.90), ALT supplementation advanced conceptus elongation (P < 0.01). Collectively, these data demonstrate that HS may affect luteal development prior to pregnancy establishment, and ALT increases conceptus elongation by12 dpe.

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Climate Change and Livestock Fertility

10.4018/978-1-6684-3686-8.ch061 ◽

2022 ◽

pp. 1256-1277

Author(s):

Vishakha Shrimali ◽

Nibedita Naha ◽

Sukanta Mondal

Keyword(s):

Climate Change ◽

Heat Stress ◽

Greenhouse Gases ◽

Follicular Development ◽

Mitigation Strategies ◽

Adaptation To Climate Change ◽

Oocyte Competence ◽

Livestock Sector ◽

Negative Effect ◽

Global Threat

Climate change is a global threat to livestock sector to so many species and ecosystem in different parts of the world. Climate change, heat stress, and nutritional stress are the major intriguing factors responsible for reduced fertility in farm animals in tropical countries. Heat and nutritional stresses affect the reproductive performance by decreasing the expression of estrous behavior, altering ovarian follicular development and hormonal profiles, compromising oocyte competence, and inhibiting embryonic development in livestock. Climate is changed by greenhouse gases that released into atmosphere through man-made activities. Livestock contribute 18% of the production of greenhouse gases itself and causes climate change including heat stress, which has direct and indirect impact on fertility of the animals as well as reduce milk production. Adaptation to climate change and lowering its negative effect by alteration of animal micro-environment using different essential technologies are the main mitigation strategies to recover heat stress damage in this respect.

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Heat Stress in Indoor Environments of Scandinavian Urban Areas: A Literature Review

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16040560 ◽

2019 ◽

Vol 16 (4) ◽

pp. 560 ◽

Cited By ~ 16

Author(s):

Karin Lundgren Kownacki ◽

Chuansi Gao ◽

Kalev Kuklane ◽

Aneta Wierzbicka

Keyword(s):

Heat Stress ◽

Literature Review ◽

Urban Areas ◽

Heat Waves ◽

Well Being ◽

Heat Index ◽

Vulnerable Groups ◽

Heat Radiation ◽

Indoor Environments ◽

Promising Alternative

Climate change increases the risks of heat stress, especially in urban areas where urban heat islands can develop. This literature review aims to describe how severe heat can occur and be identified in urban indoor environments, and what actions can be taken on the local scale. There is a connection between the outdoor and the indoor climate in buildings without air conditioning, but the pathways leading to the development of severe heat levels indoors are complex. These depend, for example, on the type of building, window placement, the residential area’s thermal outdoor conditions, and the residents’ influence and behavior. This review shows that only few studies have focused on the thermal environment indoors during heat waves, despite the fact that people commonly spend most of their time indoors and are likely to experience increased heat stress indoors in the future. Among reviewed studies, it was found that the indoor temperature can reach levels 50% higher in °C than the outdoor temperature, which highlights the importance of assessment and remediation of heat indoors. Further, most Heat-Health Warning Systems (HHWS) are based on the outdoor climate only, which can lead to a misleading interpretation of the health effects and associated solutions. In order to identify severe heat, six factors need to be taken into account, including air temperature, heat radiation, humidity, and air movement as well as the physical activity and the clothes worn by the individual. Heat stress can be identified using a heat index that includes these six factors. This paper presents some examples of practical and easy to use heat indices that are relevant for indoor environments as well as models that can be applied in indoor environments at the city level. However, existing indexes are developed for healthy workers and do not account for vulnerable groups, different uses, and daily variations. As a result, this paper highlights the need for the development of a heat index or the adjustment of current thresholds to apply specifically to indoor environments, its different uses, and vulnerable groups. There are several actions that can be taken to reduce heat indoors and thus improve the health and well-being of the population in urban areas. Examples of effective measures to reduce heat stress indoors include the use of shading devices such as blinds and vegetation as well as personal cooling techniques such as the use of fans and cooling vests. Additionally, the integration of innovative Phase Change Materials (PCM) into facades, roofs, floors, and windows can be a promising alternative once no negative health and environmental effects of PCM can be ensured.

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