Comparison of the impact of six heat-load management strategies on thermal responses and milk production of feed-pad and pasture fed dairy cows in a subtropical environment

Davison, TM; Jonsson, N.N.; Mayer, David G.; Gaughan, J. B.; Ehrlich, WK; McGowan, Michael

doi:10.1007/s00484-016-1183-2

Cited by 11 publications

(6 citation statements)

References 25 publications

(32 reference statements)

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“…Respiration rate and PS were elevated during periods of elevated THI exceeding the critical level of 80 breaths/min and MPS > 0.8 indicating critical hyperthermia (Gaughan et al 2002, Gaughan et al 2008, Davison et al 2016. The positive correlation between RR, PS and RuT and between PS, RR and THI demonstrates the negative effect of high thermal load on dairy cow's physiological variables in agreement with (Sullivan et al 2014a).…”

Section: Discussionmentioning

confidence: 56%

Effect of feeding slowly fermentable grains on productive variables and amelioration of heat stress in lactating dairy cows in a sub-tropical summer

Gonzalez-Rivas

Sullivan

Cottrell

et al. 2018

Trop Anim Health Prod

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Feeding low-fiber and high-energy diets to dairy cows is one approach to ameliorate heat stress (HS) by reducing heat increment (HI) during digestion. However, rapidly and slowly fermentable cereal grains differ in their HI. The aim of this experiment was to quantify if feeding slowly fermentable grains ameliorated the physiological responses to HS and improved milk production (MP) in dairy cows. Holstein-Friesian lactating dairy cows were housed in shaded pens and were fed either a total mixed ration (TMR) plus wheat (TMRW), a TMR plus wheat treated with 2% of a commercial starch-binding agent (TMRB), or a TMR plus corn (TMRC) (n = 8 cows per diet) during summer in Queensland, Australia. Respiration rate (RR) and panting score (PS) were measured four times a day; rumen temperature (RuT) was recorded every 20 min, and rectal temperature (RT) and milk samples were obtained every 4 days. Cows fed slowly fermentable grains had higher milk production (MP) than cows fed TMRW, and cows fed TMRC had lower RT than those fed TMRW and TMRB (P < 0.001). Rumen temperature was positively correlated with temperature-humidity index and negatively correlated with MP (P < 0.05). In summary, feeding TMRC ameliorated HS as indicated by lower RT and improved MP in dairy cows. Milk production was improved with starch-binding agents; however, this was not associated with efficient thermoregulatory responses. Furthermore, determination of RuT enabled the prediction of changes in physiological variables and productive responses due to HS in lactating dairy cows.

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Section: Discussionmentioning

confidence: 56%

Effect of feeding slowly fermentable grains on productive variables and amelioration of heat stress in lactating dairy cows in a sub-tropical summer

Gonzalez-Rivas

Sullivan

Cottrell

et al. 2018

Trop Anim Health Prod

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“…However, they have to be adapted to farm needs as they are not always sufficient to alleviate heat stress. For instance, decline in milk yield is found to be at a higher threshold (83.2 THI) with a combination of a shaded pen close to the milking room plus water sprinkling throughout the day than otherwise [ 45 ]. The frequency of cooling is also determinant for the effect: for instance, when it is increased from 5 to 8 times per day in an environment of 78.4 THI average for 40 days, cows show lower respiration rates and rectal temperatures and spend more time resting [ 93 ].…”

Section: Resultsmentioning

confidence: 99%

A systematic review of non-productivity-related animal-based indicators of heat stress resilience in dairy cattle

et al. 2018

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IntroductionProjected temperature rise in the upcoming years due to climate change has increased interest in studying the effects of heat stress in dairy cows. Environmental indices are commonly used for detecting heat stress, but have been used mainly in studies focused on the productivity-related effects of heat stress. The welfare approach involves identifying physiological and behavioural measurements so as to start heat stress mitigation protocols before the appearance of impending severe health or production issues. Therefore, there is growing interest in studying the effects of heat stress on welfare. This systematic review seeks to summarise the animal-based responses to heat stress (physiological and behavioural, excluding productivity) that have been used in scientific literature.MethodsUsing systematic review guidelines set by PRISMA, research articles were identified, screened and summarised based on inclusion criteria for physiology and behaviour, excluding productivity, for animal-based resilience indicators. 129 published articles were reviewed to determine which animal-based indicators for heat stress were most frequently used in dairy cows.ResultsThe articles considered report at least 212 different animal-based indicators that can be aggregated into body temperature, feeding, physiological response, resting, drinking, grazing and pasture-related behaviour, reactions to heat management and others. The most common physiological animal-based indicators are rectal temperature, respiration rate and dry matter intake, while the most common behavioural indicators are time spent lying, standing and feeding.ConclusionAlthough body temperature and respiration rate are the animal-based indicators most frequently used to assess heat stress in dairy cattle, when choosing an animal-based indicator for detecting heat stress using scientific literature to establish thresholds, characteristics that influence the scale of the response and the definition of heat stress must be taken into account, e.g. breed, lactation stage, milk yield, system type, climate region, bedding type, diet and cooling management strategies.

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“…Moderate changes in the heat stress risk can be addressed by short-term measures which optimize the already implemented control mechanisms such as shading, fans, adjustable opening, or cow showers and fogging devices (St-Pierre et al, 2003;Galán et al, 2018;Davison et al, 2016;Polsky and von Keyserlingk, 2017;Honig et al, 2012;Anderson et al, 2013;Valtorta and Gallardo, 2004). Depending on the boundary conditions some of those measures may become more suitable than others.…”

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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Comparison of the impact of six heat-load management strategies on thermal responses and milk production of feed-pad and pasture fed dairy cows in a subtropical environment

Cited by 11 publications

References 25 publications

Effect of feeding slowly fermentable grains on productive variables and amelioration of heat stress in lactating dairy cows in a sub-tropical summer

Effect of feeding slowly fermentable grains on productive variables and amelioration of heat stress in lactating dairy cows in a sub-tropical summer

A systematic review of non-productivity-related animal-based indicators of heat stress resilience in dairy cattle

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

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