• Energy Research

Abstract Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region's ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier's removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein × Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement.

AbstractLivestock production supports economic growth, jobs and nutrition, but contributes to and is vulnerable to climate change. A transition is thus needed for livestock systems to become more sustainable and climate resilient, with clear positive effects on the Sustainable Development Goals. It is unclear, however, where the global community should invest to support this change. We identified priority geographies for livestock system investments in 132 low- and middle-income countries (LMICs), at mid- and low latitudes. Our results show that adaptation and mitigation goals are inextricably linked for the vast majority of these countries. An equal weighting of adaptation and mitigation indicators suggests that the top five investment priorities are India, Brazil, China, Pakistan and Sudan. Across LMICs, these act as critical control points for the livestock sector’s interactions with the climate system, land and livelihoods.

The forage grass Brachiaria humidicola (Bh) has been shown to reduce soil microbial nitrification. However, it is not known if biological nitrification inhibition (BNI) also has an effect on nitrogen (N) cycling during cultivation of subsequent crops. Therefore, the objective of this study was to investigate the residual BNI effect of a converted long-term Bh pasture on subsequent maize (Zea mays L.) cropping, where a long-term maize monocrop field (M) served as control. Four levels of N fertilizer rates (0, 60, 120 and 240 kg N ha−1) and synthetic nitrification inhibitor (dicyandiamide) treatments allowed for comparison of BNI effects, while 15N labelled micro-plots were used to trace the fate of applied fertilizer N. Soil was incubated to investigate N dynamics. A significant maize yield increase after Bh was evident in the first year compared to the M treatment. The second cropping season showed an eased residual effect of the Bh pasture. Soil incubation studies suggested that nitrification was significantly lower in Bh soil but this BNI declined one year after pasture conversion. Plant N uptake was markedly greater under previous Bh compared with M. The N balance of the 15N micro-plots revealed that N was derived mainly (68–86%) from the mineralized soil organic N pool in Bh while plant fertilizer N recovery (18–24%) was not enhanced. Applied N was strongly immobilized due to long-term root turnover effects, while a significant residual BNI effect from Bh prevented re-mineralized N from nitrification resulting in improved maize performance. However, a significant residual Bh BNI effect was evident for less than one year only.

AbstractA decline in pasture productivity is often associated with a reduction in vegetative cover. We hypothesize that nitrogen (N) in urine deposited by grazing cattle on degraded pastures, with low vegetative cover, is highly susceptible to losses. Here, we quantified the magnitude of urine-based nitrous oxide (N2O) lost from soil under paired degraded (low vegetative cover) and non-degraded (adequate vegetative cover) pastures across five countries of the Latin America and the Caribbean (LAC) region and estimated urine-N emission factors. Soil N2O emissions from simulated cattle urine patches were quantified with closed static chambers and gas chromatography. At the regional level, rainy season cumulative N2O emissions (3.31versus1.91 kg N2O-N ha−1) and emission factors (0.42versus0.18%) were higher for low vegetative cover compared to adequate vegetative cover pastures. Findings indicate that under rainy season conditions, adequate vegetative cover through proper pasture management could help reduce urine-induced N2O emissions from grazed pastures.

The effect of the inclusion of Leucaena leucocephala and Tithonia diversifolia in Zebu steers receiving a diet based on improved pastures such as Brachiaria decumbens and Brachiaria hybrid cv Cayman on nitrogen (N) excretion, urinary volume and rumen microbial population was evaluated. To determine the dry matter intake and nutrient excretion, eight steers were used in a 4 × 4 Latin square design consisting of four periods and four diets. Four of them were cannulated for ruminal fluid extraction and quantification of ruminal microorganisms in three times of grazing (T0, T7 and T15). Forage intake was calculated through the external marker titanium dioxide. Diet including forages with superior protein content generated an increase in the gene copy numbers of Prevotella ruminicola and total bacteria on 15 sampling day (p < 0.001). Animals receiving diets with the dietary inclusion of Leucaena and Tithonia had daily N intakes of 228 and 113.5g N intake d−1, of which they excreted 42% and 61%, respectively. Inclusion of both protein forages increased daily urinary volume (9% and 7% d−1), with respect to the pasture-based diet. This study revealed that the inclusion of 18% Leucaena in a pasture-based diet improves the dry matter intake and N retention in Zebu steers under tropical conditions.

Comme la demande mondiale de produits d'élevage (tels que la viande, le lait et les œufs) devrait doubler d'ici 2050, les augmentations nécessaires de la production future doivent être conciliées avec les impacts environnementaux négatifs causés par l'élevage. Cet article décrit le concept LivestockPlus et démontre comment l'ensemencement de fourrages améliorés peut conduire à l'intensification durable des systèmes mixtes cultures-forages-élevage-arbres dans les tropiques en produisant de multiples avantages sociaux, économiques et environnementaux. L'intensification durable améliore non seulement la productivité des systèmes à base de fourrage tropical, mais réduit également l'empreinte écologique de la production animale et génère une diversité de services écosystémiques (SE) tels que l'amélioration de la qualité des sols et la réduction de l'érosion, de la sédimentation et des émissions de gaz à effet de serre (GES). L'intégration de fourrages améliorés à base d'herbe et de légumineuses dans des systèmes de production mixtes (cultures-élevage, arbres-élevage, cultures-arbres-élevage) peut restaurer les terres dégradées et améliorer la résilience du système à la sécheresse et à l'engorgement associé au changement climatique. Lorsqu'ils sont correctement gérés, les fourrages tropicaux accumulent de grandes quantités de carbone dans le sol, fixent l'azote atmosphérique (légumineuses), inhibent la nitrification dans le sol et réduisent les émissions d'oxyde nitreux (graminées) et réduisent les émissions de GES par unité de produit d'élevage. Le concept LivestockPlus est défini comme l'intensification durable des systèmes à base de fourrage, qui repose sur 3 processus d'intensification interdépendants : l'intensification génétique - le développement et l'utilisation de cultivars supérieurs d'herbe et de légumineuses pour augmenter la productivité du bétail ; l'intensification écologique - le développement et l'application de meilleures pratiques de gestion des ressources agricoles et naturelles ; et l'intensification socio-économique - l'amélioration des institutions et des politiques locales et nationales, qui permettent d'affiner les technologies et de soutenir leur utilisation durable. L'augmentation de la productivité animale nécessitera des efforts coordonnés pour élaborer des politiques de soutien du gouvernement, des organisations non gouvernementales et du secteur privé qui favorisent les investissements et une rémunération équitable sur le marché pour les produits et les SE fournis. Des efforts efficaces de recherche pour le développement qui promeuvent les avantages agricoles et environnementaux des systèmes à base de fourrage peuvent contribuer à la mise en œuvre de LivestockPlus dans divers contextes géographiques, politiques et socio-économiques.Mots clés : éco-efficacité, avantages environnementaux, élevage et environnement, agriculture mixte, pâturages, petits exploitants.DOI :10.17138/TGFT (3)59-82 Dado que se espera que la demanda mundial de productos ganaderos (como carne, leche y huevos) se duplique para 2050, los aumentos necesarios para la producción futura deben conciliarse con los impactos ambientales negativos que causa el ganado. Este documento describe el concepto de LivestockPlus y demuestra cómo la siembra de forrajes mejorados puede conducir a la intensificación sostenible de los sistemas mixtos de cultivos, forraje, ganado y árboles en los trópicos al producir múltiples beneficios sociales, económicos y ambientales. La intensificación sostenible no solo mejora la productividad de los sistemas basados en forraje tropical, sino que también reduce la huella ecológica de la producción ganadera y genera una diversidad de servicios ecosistémicos (ES), como la mejora de la calidad del suelo y la reducción de la erosión, la sedimentación y las emisiones de gases de efecto invernadero (GEI). La integración de forrajes mejorados de pastos y leguminosas en sistemas de producción mixtos (cultivo-ganado, árbol-ganado, cultivo-árbol-ganado) puede restaurar las tierras degradadas y mejorar la resistencia del sistema a la sequía y el anegamiento asociados con el cambio climático. Cuando los forrajes tropicales se gestionan adecuadamente, acumulan grandes cantidades de carbono en el suelo, fijan el nitrógeno atmosférico (legumbres), inhiben la nitrificación en el suelo y reducen las emisiones de óxido nitroso (gramíneas), y reducen las emisiones de GEI por unidad de producto ganadero. El concepto LivestockPlus se define como la intensificación sostenible de los sistemas basados en forrajes, que se basa en 3 procesos de intensificación interrelacionados: intensificación genética: el desarrollo y uso de cultivares superiores de gramíneas y leguminosas para aumentar la productividad del ganado; intensificación ecológica: el desarrollo y la aplicación de prácticas mejoradas de gestión de granjas y recursos naturales; e intensificación socioeconómica: la mejora de las instituciones y políticas locales y nacionales, que permiten el perfeccionamiento de las tecnologías y apoyan su uso duradero. El aumento de la productividad ganadera requerirá esfuerzos coordinados para desarrollar políticas de apoyo gubernamentales, de organizaciones no gubernamentales y del sector privado que fomenten las inversiones y una compensación justa del mercado tanto para los productos como para los ES proporcionados. Los esfuerzos efectivos de investigación para el desarrollo que promueven los beneficios agrícolas y ambientales de los sistemas basados en forraje pueden contribuir a la implementación de LivestockPlus en una variedad de contextos geográficos, políticos y socioeconómicos. Palabras clave: Ecoeficiencia, beneficios ambientales, ganado y medio ambiente, agricultura mixta, pastos, pequeños agricultores. DOI:10.17138/TGFT (3)59-82 As global demand for livestock products (such as meat, milk and eggs) is expected to double by 2050, necessary increases to future production must be reconciled with negative environmental impacts that livestock cause. This paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the sustainable intensification of mixed crop-forage-livestock-tree systems in the tropics by producing multiple social, economic and environmental benefits. Sustainable intensification not only improves the productivity of tropical forage-based systems but also reduces the ecological footprint of livestock production and generates a diversity of ecosystem services (ES) such as improved soil quality and reduced erosion, sedimentation and greenhouse gas (GHG) emissions. Integrating improved grass and legume forages into mixed production systems (crop-livestock, tree-livestock, crop-tree-livestock) can restore degraded lands and enhance system resilience to drought and waterlogging associated with climate change. When properly managed tropical forages accumulate large amounts of carbon in soil, fix atmospheric nitrogen (legumes), inhibit nitrification in soil and reduce nitrous oxide emissions (grasses), and reduce GHG emissions per unit livestock product.The LivestockPlus concept is defined as the sustainable intensification of forage-based systems, which is based on 3 interrelated intensification processes: genetic intensification - the development and use of superior grass and legume cultivars for increased livestock productivity; ecological intensification - the development and application of improved farm and natural resource management practices; and socio-economic intensification - the improvement of local and national institutions and policies, which enable refinements of technologies and support their enduring use. Increases in livestock productivity will require coordinated efforts to develop supportive government, non-government organization and private sector policies that foster investments and fair market compensation for both the products and ES provided. Effective research-for-development efforts that promote agricultural and environmental benefits of forage-based systems can contribute towards implemention of LivestockPlus across a variety of geographic, political and socio-economic contexts.Keywords: Eco-efficiency, environmental benefits, livestock and environment, mixed farming, pastures, smallholders.DOI: 10.17138/TGFT(3)59-82 نظرًا لأنه من المتوقع أن يتضاعف الطلب العالمي على المنتجات الحيوانية (مثل اللحوم والحليب والبيض) بحلول عام 2050، يجب التوفيق بين الزيادات اللازمة للإنتاج المستقبلي والآثار البيئية السلبية التي تسببها الثروة الحيوانية. تصف هذه الورقة مفهوم LivestockPlus وتوضح كيف يمكن أن يؤدي زرع الأعلاف المحسنة إلى التكثيف المستدام لأنظمة زراعة المحاصيل المختلطة في المناطق الاستوائية من خلال إنتاج فوائد اجتماعية واقتصادية وبيئية متعددة. لا يؤدي التكثيف المستدام إلى تحسين إنتاجية النظم القائمة على الأعلاف الاستوائية فحسب، بل يقلل أيضًا من البصمة البيئية للإنتاج الحيواني ويولد مجموعة متنوعة من خدمات النظم الإيكولوجية مثل تحسين جودة التربة وتقليل التعرية والترسيب وانبعاثات غازات الدفيئة. يمكن أن يؤدي دمج الأعلاف العشبية والبقولية المحسنة في أنظمة الإنتاج المختلطة (المحاصيل والماشية، والأشجار والماشية، والمحاصيل والماشية) إلى استعادة الأراضي المتدهورة وتعزيز مرونة النظام في مواجهة الجفاف والتشبع بالمياه المرتبطين بتغير المناخ. عندما تتراكم الأعلاف الاستوائية المدارة بشكل صحيح كميات كبيرة من الكربون في التربة، وتصلح النيتروجين في الغلاف الجوي (البقوليات)، وتمنع النترجة في التربة وتقلل من انبعاثات أكسيد النيتروز (الأعشاب)، وتقلل من انبعاثات غازات الدفيئة لكل وحدة من المنتجات الحيوانية. يتم تعريف مفهوم LivestockPlus على أنه التكثيف المستدام للأنظمة القائمة على الأعلاف، والتي تستند إلى 3 عمليات تكثيف مترابطة: التكثيف الجيني - تطوير واستخدام أصناف متفوقة من العشب والبقول لزيادة إنتاجية الثروة الحيوانية ؛ التكثيف البيئي - تطوير وتطبيق ممارسات محسنة لإدارة المزارع والموارد الطبيعية ؛ والتكثيف الاجتماعي والاقتصادي - تحسين المؤسسات والسياسات المحلية والوطنية، والتي تمكن من تحسين التقنيات ودعم استخدامها الدائم. ستتطلب الزيادات في إنتاجية الثروة الحيوانية جهودًا منسقة لتطوير سياسات داعمة للحكومة والمنظمات غير الحكومية والقطاع الخاص تعزز الاستثمارات وتعويضات السوق العادلة لكل من المنتجات والخدمات البيئية والاجتماعية المقدمة. يمكن أن تساهم جهود البحث من أجل التنمية الفعالة التي تعزز الفوائد الزراعية والبيئية للأنظمة القائمة على الأعلاف في تنفيذ LivestockPlus عبر مجموعة متنوعة من السياقات الجغرافية والسياسية والاجتماعية والاقتصادية. الكلمات الرئيسية: الكفاءة البيئية، الفوائد البيئية، الثروة الحيوانية والبيئة، الزراعة المختلطة، المراعي، أصحاب الحيازات الصغيرة. DOI: 10.17138/TGFT (3)59-82