Climate change impacts and seasonality changes on beef cattle in Brazil

Abstract Climate change, global warming, and natural resource depletion pose significant challenges to global beef cattle farming, with animal heat stress emerging as a widespread limitation. This is particularly critical in Brazil, a major global beef producer and exporter that supplies a substantial portion of the world's food. This study investigated the impact of seasonality changes on beef cattle welfare under various climate change scenarios, using the Temperature-Humidity Index (THI). Our analysis employed CMIP6 ensemble models for historical data and future projections, with a specific focus on the SSP5-8.5 scenario. The research focused on Brazil's most productive cattle farming regions. Historically, the North and Mid-West regions exhibited the highest THI values, mostly between September and December. Projections show low values of THI anomaly in the short-term (2021–2040). However, the medium-term (2041–2060) reveals a significant increase in THI anomalies in the Mid-West and North, with some regions approaching 30 days per month of extreme THI (values > 94). The long-term (2061–2080) represents the worst-case scenario, with high THI anomalies persisting year-round across most of Brazil. States like Acre, Amazonas, Goiás, Mato Grosso, Pará, and Rondônia are projected to experience 28–31 days per month of extreme THI during critical periods (September-December), while Paraná remains relatively low. The findings underscore an urgent need for robust adaptation strategies, including genetic improvement, integrated crop-livestock systems, and precision livestock farming technologies, alongside national mitigation efforts, to ensure the long-term viability and sustainability of Brazilian beef production.