With a pioneering, comprehensive approach on a global scale, Brazilian researchers have developed a methodology that allows them to project the physiological responses of herds of different production animal species to the impacts of climate change between 2050 and 2100.
It is estimated that if the average temperature increase of 2 °C is reached by 2050, critical situations for agriculture and for animal and human health will be recorded even more frequently and intensely. Therefore, the results of the research are important for structuring public policies, decision-making, and private sector actions aimed at avoiding compromising production and food security.
According to the study, small ruminants will be more impacted by climate change in countries in the Northern Hemisphere than the same animals in the Southern Hemisphere in the three analyzed scenarios (2050, 2075, and 2100). The study projects an average increase of up to 68% in respiratory rate for animals in the North compared to those in the South.
Among ruminants raised in the tropics, dairy farming in the South will be the most vulnerable to heat stress, while goats and beef cattle will be more resilient due to phenotypic plasticity. This is the ability to change physical characteristics (phenotypes) depending on environmental conditions, allowing for adaptation without altering the genetic code (genotype).
Among production animals in the Southern Hemisphere, laying hens and quail were identified as the most susceptible to heat stress, with predictions of up to a 40% increase in breaths per minute by 2100. These findings were published in the scientific journal Environmental Impact Assessment Review.
"With global temperatures rising and weather events becoming more extreme, it'll be necessary to develop resistant and adaptable breeds, as well as high-level production environments with temperature control. Our study provides crucial insights to guide animal production adaptation policies aimed at food security and environmental sustainability. We know that adaptations will need to be made, including management focused on the selection and conservation of genetic resources," says Iran José Oliveira da Silva , coordinator of the Center for Research on the Environment (NUPEA) at the Luiz de Queiroz School of Agriculture at the University of São Paulo (ESALQ-USP) and one of the scientists in the group.
Silva was the advisor for the doctoral thesis of Robson Mateus Freitas Silveira , a zootechnician from ESALQ-USP and the first author of the article. The text is the fifth in a series of others already published from his thesis.
"We began this series by defining, for the first time, what a sustainable animal would be. We understand it to be one with low net carbon emissions, efficient in feed conversion and adaptation, regardless of climatic conditions, as well as clinically healthy and high-performing. We then developed a methodology to identify these animals, characterized them, and discussed them. Subsequently, we sought to identify phenotypic biomarkers to identify them," explains Silveira, who received support from FAPESP through scholarships 22/14250-8 and 23/16733-9 .
This year, Silveira won the Brazilian Society of Animal Science's Award of Excellence , which recognizes performance, dedication to research, and contributions to the advancement of the field in Brazil.
Methodology
To project how climate change will impact thermoregulatory responses, the scientists used 12 databases collected in Brazil, Italy, and Spain.
First, they tabulated, organized, and standardized biological, productive, and environmental data. Next, they evaluated adaptive responses and identified phenotypic biomarkers of production animals using exploratory factor analysis and multiple regression. The adaptive profile of different animals was traced in both hemispheres.
Then, the group developed intelligent models using machine learning and multivariate analysis. Meteorological data were used to project climate scenarios according to the Intergovernmental Panel on Climate Change (IPCC-RCP 4.5, a conservative model) in conjunction with the United Nations (UN).
The researchers also analyzed adaptive responses in farm animals, including thermoregulatory, hematological, morphological, hormonal, and biochemical variables. The species included are sheep, goats, dairy and beef cattle, pigs (piglets), poultry, and quail.
Silva points out that hematological variables, as measured by complete blood tests, are important biomarkers for studying animal adaptation to ambient temperature — even more so than coat morphology.
The authors conclude that animal adaptation is essential for addressing climate change scenarios, particularly with regard to balancing production and resilience. Although the Northern Hemisphere is more productive and will be most affected, the South should invest in selecting biomarkers, crossbreeding, and conserving local breeds. The future of food security depends on integrating genetics, public policy, and sustainable innovation on a global scale.
Paradox
The UN points out that the world population is expected to grow from the current 8 billion people to around 10 billion by 2050. Even with countries' efforts to ensure food security, it is estimated that 8.2% of the population went hungry in 2024, while waste still accounts for one-third of the food produced worldwide.
In addition, the global food production chain results in high levels of greenhouse gases and deforestation for livestock and agriculture, accounting for 31% of global emissions .
This population and income growth is putting increasing pressure on the food system, which is also impacted by climate change, with rising temperatures, changing rainfall patterns, and more frequent extreme weather events, such as droughts and floods.
One consequence is that countries are finding it difficult to meet the Sustainable Development Goals (SDGs). These consist of 17 interconnected goals defined by the United Nations that seek to eradicate poverty, combat inequality and hunger, protect the environment and climate, and ensure justice for all by 2030.
For the researchers, the study provides a scientific basis for developing more sustainable and resilient animal production systems in line with the SDGs.
Some of the world's largest meat producers are Brazil, the United States, and China. According to the National Supply Company (CONAB), Brazil's beef, pork, and poultry production is expected to reach 31.57 million tons in 2025, nearly matching the 2024 record of 31.58 million tons.
In terms of exports, Brazil sold 1.78 million tons of beef between January and July and is expected to export around 5.2 million tons of chicken by the end of the year, despite the impacts caused by U.S. tariffs and avian flu.
The group emphasizes in the study that it is urgent and necessary to intensify the poultry farming production system because these animals cannot withstand high temperatures.
"Dairy cattle and poultry, whether for egg production or slaughter, will already suffer immediate effects on the production cycle. This is a warning sign for future production. That's why it's important to work together on genetics and the environment. We seek to analyze what will happen in the future to warn and alert producers, researchers, and public policymakers," Silva told Agência FAPESP.
Limitation
In the article, the scientists note difficulties with countries' databases, sometimes due to small sample sizes and different methodologies for collecting adaptive responses, in addition to the costs of laboratory analyses. Only rectal temperature and respiratory rate were common variables in the 12 databases.
Another limitation is the lack of a database for ruminants and monogastrics (such as cattle, sheep, and poultry) in fully confined systems, which are used in some countries, particularly China and the United States.
"This work is just the tip of the iceberg. We've collected the initial data and now we need to add partner databases and expand the information to different regions of the world, allowing us to compare and study the effects in other scenarios. The study led by Robson is pioneering in its contextualization, showing that partnerships between countries and researchers lead to conclusions that can be useful to everyone," says Silva.
Silveira points out that the next step is to collect data and phenotypic information on birds and pigs of different breeds throughout Brazil to build a database that can be used to predict how these animals will adapt and produce in response to environmental changes. This is the focus of his postdoctoral internship at NUPEA, supported by FAPESP .
In the article, the group suggests that further research should deepen our understanding of the relationship between thermoregulatory responses and productive performance to strengthen food security strategies.
About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe .
