Heat stress in livestock under climate change: Critical advances, emerging technologies, and pathways to resilient production systems – A systematic review

Heat stress is a major challenge to livestock production under climate change, affecting productivity, animal welfare, and food security. This systematic review (PRISMA 2020) evaluates 166 peer-reviewed studies to assess the effectiveness, scalability, and limitations of mitigation strategies across livestock systems. Conventional strategies (e.g., cooling systems, nutritional supplementation, and selective breeding) improve thermoregulation, productivity, and health, but are often constrained by high costs and context-specific performance. Emerging innovations, including CRISPR-based gene editing, epigenetic selection, microbiome engineering, smart cooling materials, wearable biosensors, digital twin modelling, and artificial intelligence enabled cyber-physical systems, demonstrate substantial promise for enhancing thermotolerance and adaptive capacity. However, their long-term efficacy, ethical implications, regulatory feasibility, and accessibility for smallholder and resource-limited systems remain inadequately addressed. This review advances current knowledge by integrating biological, technological, and system-level strategies within a sustainability framework, with particular emphasis on energy efficiency, scalability, and inclusivity. It highlights critical knowledge gaps, including limited understanding of chronic and transgenerational heat stress effects and the need for integrated, systems-based solutions. Future progress will depend on coordinated, interdisciplinary approaches that combine conventional and advanced strategies to support resilient and climate-adaptive livestock systems.