Practices for Alleviating Heat Stress of Dairy Cows in Humid Continental Climates: A Literature Review

Fournel, Sébastien; Ouellet, V.; Charbonneau, Édith

doi:10.3390/ani7050037

Cited by 106 publications

(98 citation statements)

References 92 publications

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“…The airflow provided by fans facilitates the evaporation of water from the skin, which carries heat directly away from the cows' body (132). Heat abatement using this type of active cooling system reduces the body temperature and respiration rate, increases production performance, and improves the immune function of heat-stressed cows (115,116,133). Alternatively, the feedline soakers may be replaced by high pressure misters or foggers placed on the face of fans.…”

Section: Management Interventionsmentioning

confidence: 99%

Heat Stress Impacts Immune Status in Cows Across the Life Cycle

2020

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Heat stress has a myriad of effects on dairy cattle across the life cycle. Whereas, the most commonly recognized impacts are associated with production responses, emerging evidence indicates that heat stress profoundly alters the immune response of calves and cows, from the prenatal stage through lactation. For example, in utero heat stress reduces passive immune transfer regardless of colostrum source, relative to normothermic conditions in late gestation. Dry cows exposed to heat stress have lower immunoglobulin responses to ovalbumin vaccination, but this effect dissipates with cooling following parturition. Conversely, cows under heat stress when dry exhibit carryover effects on the innate arm of the immune system in early lactation. In this paper we review the effects of heat stress throughout the life cycle of the dairy cow, with particular emphasis on the impact of heat stress during late gestation on the cow and the developing fetus, both before and after parturition. In addition, the impact of altered immune status under heat stress on other physiological systems, especially those supporting milk production, are considered. Finally, management interventions to prevent and reverse the effect of heat stress are presented.

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Section: Management Interventionsmentioning

confidence: 99%

Heat Stress Impacts Immune Status in Cows Across the Life Cycle

2020

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“…Under such conditions, as in the example of the reference barn Bétera, natural ventilation offers almost no possibility for further adaptation by adjusting the opening configurations. In such buildings, fans and showers or fogging devices have been implemented in the past to alleviate the heat load and enable high milk yields during hot periods (Ortiz et al, 2015;Fournel et al, 2017). The fans can in principle decrease or increase the air speed in the animal-occupied zone as they induce a flow that can be aligned or opposed to the naturally induced flow .…”

Section: Adaptation Options For Animal Housingmentioning

confidence: 99%

Heat stress risk in European dairy cattle husbandry under different climate change scenarios – uncertainties and potential impacts

et al. 2019

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Abstract. In the last decades, a global warming trend was observed. Along with the temperature increase, modifications in the humidity and wind regime amplify the regional and local impacts on livestock husbandry. Direct impacts include the occurrence of climatic stress conditions. In Europe, cows are economically highly relevant and are mainly kept in naturally ventilated buildings that are most susceptible to climate change. The high-yielding cows are particularly vulnerable to heat stress. Modifications in housing management are the main measures taken to improve the ability of livestock to cope with these conditions. Measures are typically taken in direct reaction to uncomfortable conditions instead of in anticipation of a long-term risk for climatic stress. Measures that balance welfare, environmental and economic issues are barely investigated in the context of climate change and are thus almost not available for commercial farms. Quantitative analysis of the climate change impacts on animal welfare and linked economic and environmental factors is rare. Therefore, we used a numerical modeling approach to estimate the future heat stress risk in such dairy cattle husbandry systems. The indoor climate was monitored inside three reference barns in central Europe and the Mediterranean regions. An artificial neuronal network (ANN) was trained to relate the outdoor weather conditions provided by official meteorological weather stations to the measured indoor microclimate. Subsequently, this ANN model was driven by an ensemble of regional climate model projections with three different greenhouse gas concentration scenarios. For the evaluation of the heat stress risk, we considered the number and duration of heat stress events. Based on the changes in the heat stress events, various economic and environmental impacts were estimated. The impacts of the projected increase in heat stress risk varied among the barns due to different locations and designs as well as the anticipated climate change (considering different climate models and future greenhouse gas concentrations). There was an overall increasing trend in number and duration of heat stress events. At the end of the century, the number of annual stress events can be expected to increase by up to 2000, while the average duration of the events increases by up to 22 h compared to the end of the last century. This implies strong impacts on economics, environment and animal welfare and an urgent need for mid-term adaptation strategies. We anticipated that up to one-tenth of all hours of a year, correspondingly one-third of all days, will be classified as critical heat stress conditions. Due to heat stress, milk yield may decrease by about 2.8 % relative to the present European milk yield, and farmers may expect financial losses in the summer season of about 5.4 % of their monthly income. In addition, an increasing demand for emission reduction measures must be expected, as an emission increase of about 16 Gg of ammonia and 0.1 Gg of methane per year can be expected under the anticipated heat stress conditions. The cattle respiration rate increases by up to 60 %, and the standing time may be prolonged by 1 h. This causes health issues and increases the probability of medical treatments. The various impacts imply feedback loops in the climate system which are presently underexplored. Hence, future in-depth studies on the different impacts and adaptation options at different stress levels are highly recommended.

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“…We hypothesized that heavy breathing, as reported on a minute-by-minute basis by the tags, would accurately reflect heat-load status as recorded by continuous intravaginal temperature loggers (as a reliable measure of core body temperature, including diurnal changes; Vickers et al, 2010), and that response to a cooling intervention (showers and fans) would also be captured by these tags. Indeed, environmental management, including cooling mechanisms such as fans, sprinklers, and waterbeds (Fournel et al, 2017) can be used to mitigate the effects of excessive heat load. However, a significant amount of potable water is used in cow cooling (Chen et al, 2015), and the ability to cool only specific at-risk groups of cows on targeted days and times could save resources.…”

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confidence: 99%