Agricultural Sciences: Techniques and Innovations Vol. 9

Global livestock systems face an unprecedented convergence of pressures: rising protein demand from an expanding human population, mounting obligations to reduce greenhouse gas (GHG) emissions — particularly methane — and growing imperatives to uphold animal welfare standards in the face of climatic change. Sustainable intensification has been extended to livestock production, encompassing approaches that increase productivity per unit of input, including land, water, feed, and greenhouse gas emissions, while maintaining or enhancing the natural resource base. This review synthesises current evidence on the relationships between livestock production, GHG emissions, and the principles of sustainable intensification, examining how these three domains interact under evolving climatic conditions. Enteric fermentation and manure management together account for the majority of agricultural methane and nitrous oxide emissions, yet livestock also provide irreplaceable nutritional, economic, and cultural services to billions of people globally. Sustainable intensification offers a conceptual and practical framework for increasing production efficiency whilst reducing environmental footprints, though its implementation requires careful calibration across different agro-ecological contexts and livestock species. A range of methane mitigation strategies — including dietary manipulation, feed additives such as 3-nitrooxypropanol (3-NOP), selective breeding, and improved manure management — show considerable promise, yet none alone is sufficient to meet international climate targets. Animal welfare considerations, often marginalised in emission-reduction discourse, emerge as both an ethical imperative and a productivity lever, particularly as heat stress from climate change increasingly compromises performance and health across livestock species. Policy frameworks at national and international levels must align food security goals with climate commitments, recognising that trade-offs between protein supply, mitigation ambition, and welfare standards are real but not irresolvable. This review concludes that progress will require integrated, multi-disciplinary approaches that place the livestock sector at the intersection of food systems transformation and climate action.