Most beef cattle in South America experience hundreds to thousands of hours of heat-related discomfort each year

A new scientific study has quantified, for the first time, how much heat stress beef cattle actually experience across South America — as cumulative time spent in heat-related discomfort. Using climate data from 636 cattle-producing locations across Brazil, Argentina, Colombia, Paraguay, and Uruguay, the researchers analyzed five years of weather conditions and applied the Welfare Footprint Framework (WFF) to translate heat exposure into time animals spend in different intensities of thermal discomfort.

Rather than asking whether cattle are exposed to stressful temperatures, the study measured how long animals are predicted to be affected, and how severe that experience is, over the course of a year.

Heat stress as a dominant condition

The analysis shows that heat stress is not confined to heat waves or short seasonal peaks. In regions classified as high thermal risk or above, cattle experience heat stress on most days of the year.

Across these regions, each animal was estimated to spend between 280 and nearly 2,800 hours per year in moderate to intense thermal discomfort. In the most extreme areas, animals experienced heat stress for more than 300 days annually, spending on average over 11 hours per day under conditions that challenge thermoregulation.

At higher intensities, heat stress disrupts essential biological functions. Animals reduce or stop grazing and ruminating, remain immobile for prolonged periods, and engage in sustained, intense panting as they attempt to transfer excess body heat. When these conditions persist, they represent prolonged negative affective states that accumulate over substantial portions of the animals’ lives.

“This study shows that heat stress is not an occasional problem but a daily reality for millions of cattle in South America, with profound implications for animal welfare and productivity,” says Dr. Cynthia Schuck-Paim, lead author of the study.

A new application of the Welfare Footprint Framework

This research represents a novel application of the Welfare Footprint Framework to a large-scale environmental challenge affecting farm animals. The framework quantifies welfare impact as cumulative time spent in negative experiences of different intensities, allowing the magnitude of heat stress to be compared across regions and contextualized alongside other major welfare challenges in animal production.

By expressing heat stress in hours of lived discomfort, the study moves beyond identifying risk factors and makes the welfare impact directly measurable. The authors note that the estimates are conservative, as they account only for the immediate experience of thermal discomfort and do not include downstream effects such as increased disease risk or heat-related mortality.

Shade substantially reduces welfare impact — and is economically viable

The study also evaluated the effect of providing effective shade in pasture-based systems or feedlot operations. Modeling showed that shade could reduce time spent in the most severe category of thermal discomfort by around 85%, lowering annual exposure from hundreds of hours to just a few dozen in the hottest regions.

These welfare improvements were achieved alongside economic benefits. Using real-world production data, the analysis found that shade structures typically generate net returns of US$12–16 per animal through improved feed efficiency and weight gain even if used only briefly, during the finishing phase. Much higher gains are expected with the use throughout the production cycle. This makes shade provision one of the most cost-effective welfare interventions currently identified for beef cattle in hot climates.

Additionally, welfare gains can be achieved through systems that also deliver environmental benefits. Silvopastoral systems — including trees integrated into pastures or agroforestry-based cattle production — provide natural shade while contributing to biodiversity, soil protection, and landscape resilience. Other shade-providing infrastructure can also be used in feedlot settings to improve the local microclimate without altering the core production system. In this context, shade becomes a rare and highly cost-effective intervention that simultaneously advances animal welfare, environmental sustainability, and productivity.

For producers and companies, the results underscore that heat stress should be treated not as a marginal management issue, but as a central animal welfare and sustainability concern, with solutions that align welfare improvement with economic and ecological goals.

Publication: The Welfare Impact of Heat Stress in South American Beef Cattle and the Cost-Effectiveness of Shade Provision. Animals. https://doi.org/10.3390/ani16020231

For more information: media@welfarefootprint.org.

The Welfare Footprint Framework is freely available for research and policy use at welfarefootprint.org