The aim of the methodology developed in these guidelines is to introduce a harmonized international approach assessing nutrient flows and impact assessment for eutrophication and acidification for livestock supply chains taking the specificity of the various production systems involved into consideration. The methodology strives to increase understanding of nutrient use efficiency and associated environmental impacts and to facilitate the improvement of livestock systems’ environmental performance. The guidelines are a product of the Livestock Environmental Assessment and Performance (LEAP) Partnership, a multi-stakeholder initiative whose goal is to improve the environmental sustainability of livestock sector through better metrics and data. Nutrient use in livestock production systems increased over the last decades due to the increased demand for livestock production. This demand is mainly driven by the increase in the population growth, population income, and urbanization. Consequently, in livestock supply chains, nutrient losses into the environment have contributed to environmental burdens such as climate change, air and water pollution, degradation of soil quality, loss of biodiversity and human health issues. Therefore, there is strong interest in measuring nutrient flows to improve the environmental performance of the livestock sector. The objectives of these guidelines are: •To develop a harmonized, science-based approach resting on a consensus among the sector’s stakeholders; •To recommend a scientific, but at the same time practical, an approach that builds on existing or developing methodologies; •To promote a harmonised approach to assess nutrient flows and impact assessment, relevant for global livestock supply chains; •To identify the principal areas where ambiguity or differing views exist concerning the methodological framework. During the development process, these guidelines were submitted for technical review and public review. The purpose is to strengthen the advice provided and ensure it meets the needs of those seeking to improve nutrient use efficiency and environmental performance through sound assessment practice. This document is not intended to remain static. It will be updated and improved as the sector evolves and more stakeholders become involved in the LEAP, and as new methodological frameworks and data become available. The guidelines developed by the LEAP Partnership gain strength because they represent a multi-actor coordinated cross-sectoral and international effort to harmonize assessment approaches. Ideally, the harmonization leads to greater understanding, transparent application and communication of metrics, and, not least, real and measurable improvement in environmental performance.

The Technical Advisory Group (TAG) for Water Use Assessment, composed by 30 international experts, has developed guidelines on water footprinting for livestock supply chains. The mandate of the Water TAG was to provide recommendations to monitor the environmental performance of feed and livestock supply chains over time so that progress towards improvement targets can be measured; apply the guidelines for feed and water demand of small ruminants, poultry, large ruminants and pig supply chains; build on and go beyond the existing FAO LEAP guidelines; and pursue alignment with relevant International Organization for Standardization (ISO) standards, specifically ISO 14040, ISO 14044 (ISO, 2006b and 2006a) and ISO 14046 (ISO, 2014). The guidelines on water use assessment include the impact assessment: the assessment of the environmental performance related to water use of a livestock-related system by assessing potential environmental impacts of blue water consumption following the water scarcity footprint according to the framework provided by ISO 14046 (ISO, 2014); and the assessment of the system’s productivity of green and blue water. The guidelines are thus intended to support the optimization of use of water resources and the identification of opportunities to decrease the potential impacts of water use in livestock production. The Water TAG guidance is relevant for livestock production systems, including feed production from croplands and grasslands, and production and processing of livestock products (cradle-to-gate). It addresses all livestock production systems and livestock species considered in existing LEAP animal guidelines: poultry, pig, small ruminant and large ruminant supply chains.

The production and the use of feed additives influence the environmental impact of livestock production. The use of feed additives significantly acts on feed efficiency, and thus animal and environmental performance. The methodology developed in these guidelines aims to introduce a harmonized international approach to the assessment of the environmental performance of feed additives in livestock supply chains taking into consideration the impact of their production and use all along the supply chain for large ruminants, pigs and poultry. The objective of this technical document is twofold: on the one hand, to provide detailed guidance on how to measure the environmental performance of the production of feed additives, and on the other hand, how to measure the effects of feed additives on the environmental performance of livestock products. The guidelines on the environmental performance of feed additives in livestock supply chains are intended to be used with other published LEAP guidelines.

The evaluation of the project “Livestock Environmental Assessment and Performance (LEAP) Partnership” covered the three phases of the LEAP Partnership (2012–2021). The evaluation found that the project responded to an existing demand to advance towards a science-based benchmarking of the environmental performance of the livestock sector. The LEAP partnership was a cost-effective approach that contributed to consensus building and greater understanding of the factors influencing environmental performance by providing a neutral forum for discussion and negotiation. The evaluation provides six recommendations: i) strengthen the project’s theory of change to reflect the complexity of learning and innovation, including gender perspective; ii) strengthen the multi-stakeholder partnership governance, management and procedures; iii) strengthen collaboration with other initiatives such as the Global Agenda for Sustainable Livestock (GASL) and the Global Livestock Environmental Assessment Model (GLEAM); iv) reduce the budget uncertainty through improved long-term planning and a strengthened resource mobilization strategy; v) update and improve the dissemination strategy; and vi) develop an outreach strategy with clear goals.

The Technical Advisory Group (TAG) on biodiversity, hereafter called Biodiversity TAG, is composed of 25 international experts in ecology, biodiversity indicators, agronomy, life cycle assessment, livestock production systems, and environmental science. Their backgrounds, complementary between systems and regions, allowed them to understand and address different perspectives. The aim of the methodology developed in these guidelines is to introduce a harmonized international approach for assessing the impacts of livestock on biodiversity. The livestock sector is a major user of natural resources (land in particular) and an important contributor to pollution (e.g. causing nutrient losses, increasing greenhouse gas emissions), which makes it one of the sectors with the highest impact on biodiversity. At the same time, livestock production is one of the few sectors with not only negative but also positive impacts on biodiversity; therefore, the sector can pull two levers to improve its biodiversity performance – mitigate harm and maximize benefits. Many environmental assessments of the livestock sector have not addressed biodiversity because of its intrinsic complexity. These guidelines strive to include biodiversity in environmental assessments, in order to increase the understanding of the impacts of livestock on biodiversity and to reveal possible synergies or trade-offs with other environmental criteria or Sustainable Development Goals (SDGs). Several indicators in these guidelines are also of relevance for the UN Decade on Ecosystem Restoration.

Addressing methane emissions from livestock and rice systems is vital for promoting sustainable agriculture and mitigating climate change. This FAO report comprehensively addresses methane emissions in agriculture and their impact on global greenhouse gas levels. By analysing sources, sinks, quantification methods, and mitigation strategies, this publication highlights challenges and opportunities to reduce methane emissions from livestock and rice production systems.

The assessment of water productivity in livestock supply chains has a critical role to play in developing productive and sustainable food production systems worldwide. In particular, the evaluation of water productivity improvement options is key to addressing growing food demand and the projected impacts of climate change under conditions where the availability of land and water resources is increasingly limited. In this report, we review current applications of water productivity analysis in livestock supply chains. To do so, we analysed 50 livestock water productivity studies carried out in various regions of the world from 1993 to the present time. We reviewed the assessment goals, system boundaries, methodological approaches, water flows, modelling tools, databases, livestock species and the main findings in each of the studies. We found that there was no consistency in the methods and approaches used to assess water productivity in livestock production chains. The studies varied widely in terms of their assessment goals, methodology, and the sources of water used for the analysis. The main methodological differences were the inclusion or exclusion of background processes, such as water input and the treatment of precipitation in accounting for water use in livestock production processes. Another key issue was the missing uncertainty assessment, which can be classified as input data uncertainty or model uncertainty, as well as choice uncertainties. The review recommends the further development of guidelines that ensure a consistent and coordinated application of water productivity analysis of livestock production systems world-wide.