Strain-Specific Heat Stress Responses in Broiler Chickens Under Climate Change: A Systematic Review

This study systematically reviewed published research on the responses of broiler strains to heat stress associated with climate change. Databases included Scopus, Google Scholar, Taylor and Francis, Wiley, and Springer with the keywords: broiler, thermal environment, climate change, temperature, heat stress, and performance. The articles included were published from 2000 until 2024. The results showed 48 relevant articles identified from different regions: Asia, Europe, the Americas, and Africa. The most frequently studied broiler strains were Ross 308 (n=14), Arbor Acres (n=11), and Cobb 500 (n=7). Results indicated that heat stress was consistently associated with reduced feed intake, lower body weight gain, impaired feed conversion, and increased mortality. Strain-specific responses varied: Ross 308 tended to show smaller reductions in feed intake, Hubbard maintained more stable ADG and FCR, whereas Arbor Acres and Line A showed greater performance declines. These variations were influenced by genetic background, bird age, environmental conditions, and experimental design, with none of the strains demonstrating absolute tolerance. This review emphasizes the importance of accounting for strain-specific variation in heat tolerance as part of adaptive management strategies, and highlights the need for further research on local and crossbred strains to support sustainable poultry production under a warming climate.