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La communauté rurale de Téssékéré est à 97 % peule avec comme principale activité l’élevage extensif. La transhumance est pratiquée dans cette zone sur de petites ou grandes distances en fonction de la disponibilité du fourrage. Les enquêtes réalisées auprès des éleveurs de la localité ont permis d’identifier leurs pratiques pastorales et de recueillir leur perception sur l’état actuel de la végétation et son évolution, et les facteurs responsables de cet état. L’arbre est utilisé dans cette communauté dans l’alimentation humaine (94,3 %) et animale (94,3 %), dans la pharmacopée (82,8 %), et dans les usages domestiques comme bois de service (28,6 %) et de construction (37,14 %). Pour accéder aux différentes parties des arbres, les éleveurs pratiquent souvent la coupe ou l’élagage. Les espèces les plus exploitées sont Balanites aegyptiaca (14,3 % à 88,6 %), Calotropis procera (14,3 % à 28,6 %), Sclerocarya birrea (8,6 % à 25,7 %), Adansonia digitata (8,6 % à 20 %) selon les zones et les besoins. Une majorité d’éleveurs (51,4 %), conscients aujourd’hui de l’impact de ces pratiques sur le peuplement ligneux, a abandonné la coupe et pratique l’abaissement des branches pour nourrir le bétail.

Throughout the world, livestock grazing systems (LGS) include, and provide livelihoods for, many rural populations. These LGS are represented in a wide variety of agroecological contexts and offer a huge variety of system organization. They contribute to sustainable food systems by providing multiple products including low-cost edible proteins and energy, draft power, outputs (carbon and soil nutrient regulation, landscape and biodiversity maintenance), roles (local development support in harsh environments, contribution to the circular economy) and benefits to populations (revenue, employment, and cultural assets). These multiple functions can be described through a multifunctional conceptual model specified for LGS. Applied to cases in Africa, Asia, Latin America and Europe, the framework enables the assessment of these systems in a holistic manner that includes four dimensions: production, social, environmental and local development. These dimensions and associated local indicators demonstrate the potential important contribution that LGS may deliver to sustainable food systems. Management of interactions and trade-offs between these functions may be improved using such a model in a multi-stakeholder approach. Some of the functions and balance between them might have been overlooked in the consideration of European food systems. IPAF Región NOA Fil: Ickowicz, Alexandre. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Ickowicz, Alexandre. Selmet, Univertité Montpellier, Cirad, INRAE; Francia Fil: Ickowicz, Alexandre. Cirad, UMR Selmet, Montpellier; Francia Fil: Hubert, Bernard. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Hubert, Bernard. INRAE. Unité d'Ecodéveloppement; Francia Fil: Blanchard, Mélanie. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Blanchard, Mélanie. Selmet, Univertité Montpellier, Cirad, INRAE; Francia Fil: Blanchard, Mélanie. Cirad, UMR Selmet Hanoï; Vietnam Fil: Blanchard, Mélanie. Nias, Hanoï; Vietnam Fil: Blanfort, Vincent. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Blanfort, Vincent. Selmet, Univertité Montpellier, Cirad, INRAE; Francia Fil: Blanfort, Vincent. Cirad, UMR Selmet, Montpellier; Francia Fil: Cesaro, Jean-Daniel. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Cesaro, Jean-Daniel. Selmet, Univertité Montpellier, Cirad, INRAE; Francia Fil: Cesaro, Jean-Daniel. Cirad, UMR Selmet, ISRA, PPZS, Saint-Louis, Senegal Fil: Diaw, Arona. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Diaw, Arona. Laiterie du Berge; Senegal Fil: Lasseur, Jacques. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Lasseur, Jacques. Selmet, Univertité Montpellier, Cirad, INRAE; Francia Fil: Huyen, Le Thi Thanh. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Huyen, Le Thi Thanh. Nias, Hanoï; Vietnam Fil: Li, Li. Xi'an Jiaotong-Liverpool University. Department of Health and Environmental Sciences; China Fil: Mauricio, Rogerio Martins. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Mauricio, Rogerio Martins. Universidade Federal de Sao Joao. Biotechnology Department; Brasil Fil: Cangussu, Mauroni. Universidade Federal de Sao Joao. Biotechnology Department; Brasil Fil: Müller, Jean-Pierre. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Müller, Jean-Pierre. Sens, Univ Montpellier, Cirad, Montpellier; Francia Fil: Müller, Jean-Pierre. Cirad, UMR Sens, Montpellier; Francia Fil: Quiroga Mendiola, Mariana. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Quiroga Mendiola, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región NOA; Argentina Fil: Quiroga Roger, Juan Alfonso. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región NOA; Argentina Fil: Vera, Tomas Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región NOA; Argentina Fil: Ulambayar, Tungalag. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Ulambayar, Tungalag. Zoological Society of London. Representative Office Ulaanbaatar; Mongolia Fil: Wedderburn, Liz. FAO. Global Agenda for Sustainable Livestock “Restoring value to grassland” network; Italia Fil: Wedderburn, Liz. AgResearch Ltd.; Nueva Zelanda

Trees in dryland forests and wooded areas provide key ecosystem services such as animal feed, timber, fruits and, regulation of soil and water cycles. Equally, the presence of livestock in dryland woody areas can also play an important role in the local ecosystem; not only are they a source of income for local communities, but they also help vegetation and mobilise stored biomass. When both of these ecosystem elements are wisely combined – livestock and trees – it creates an integrated agricultural system that can boost the local ecosystem, representing a welcome agro-ecological transition in livestock farming. The ‘Grazing with Trees’ report gives a thorough assessment of the positive role that optimized extensive grazing livestock farming can play in the management and restoration of drylands’ forests and lands with trees. It assesses and provides sound evidence on the benefits of applying an integrated landscape approach and utilizing farmers and pastoralists’ knowledge to halt desertification, increase resilience, and enhance food security under the actual changing scenario. The report confirms the importance of agroforestry as a primary pathway for forest restoration in dryland areas as recommended by FAO’s State of Forests 2022, and its recommendations encourage landscape planners and decision makers to consider livestock as allies, carefully restore tree cover and accelerate action to promote healthy ecosystems.

In the dry areas of western Africa, the over-exploitation of forestry resources and the lack of tree regeneration lead to the degradation of agroforestry parklands. Such parklands could be better managed if the multiple services provided by the trees were well identified and valorized. However, there is little information on the local knowledge of' tree species regarding their functions, uses and services. Likewise, local stakeholders' perceptions of the relation between the species aptness for the above functions and uses and their functional traits is not well known. This study focuses on local knowledge of tree species in parklands of the Segou region in Mali, in order to identify specific uses or multifunctionalities that could be highlighted in improving agroforestry systems. Qualitative surveys have been carried out to identify users' perceptions of tree functions and functional traits. Findings show the possibility of classifying species by relevant functional groups, i.e. woody/timber trees, fruit/cash crop trees and trees related to livestock. Functional traits were not easily identified by farmers and the related information was difficult to analyze. Moreover, the perception of functions and traits depended on user groups (craftsmen, crop farmers, livestock farmers, traditional health practitioners, women etc.) and on agro-environmental and socio-economic contexts (activities, knowledge, means and practices). Therefore, scientific databases composed of lists of functions and traits for a given species have no generic value and must be valued depending on the context which may or may not enhance the substitutions between species for each use.

Deux principaux systèmes d’élevage bovin cohabitent dans le bassin de la Donga au nord du Bénin : l’élevage semi-sédentaire et l’élevage mobile. Ce bassin, situé dans la zone agroécologique subhumide de l’Afrique de l’Ouest, a subi ces dernières décennies deux changements majeurs : a) une augmentation des besoins en produits animaux et b) l’expansion des terres cultivées qui entraîne une diminution de l’accès aux ressources fourragères et à l’eau, une plus grande mobilité des troupeaux, et des conflits plus fréquents entre cultivateurs et éleveurs mobiles. Face à ces contraintes, les pouvoirs publics privilégient la sédentarisation des éleveurs mobiles. L’élevage mobile étant pourvoyeur de jeunes animaux aux élevages semi-sédentaires, la dynamique de sédentarisation crée une incertitude quant à l’approvisionnement de la région en bétail bovin et en viande par un élevage semi-sédentaire qui deviendrait largement majoritaire. Pour appréhender la question de besoins croissants en produits animaux, la production de bétail a été simulée afin d’évaluer l’effet d’une incitation des pouvoirs publics à la sédentarisation des éleveurs mobiles. Les productivités numérique et en viande ont été simulées sous différentes hypothèses d’amélioration des performances zootechniques des élevages semi-sédentaires. L’ensemble des scénarios ont été construits à partir de l’hypothèse de l’augmentation du cheptel semi-sédentaire directement liée à la sédentarisation d’une partie des éleveurs mobiles. Une simulation obtenue à l’aide du modèle de projection démographique Dynmod suggère que la sédentarisation des éleveurs mobiles romprait la complémentarité locale entre les systèmes d’élevage et conduirait à une perte de production de viande. En outre, aucun des scénarios d’amélioration explorés ne suffirait à compenser la perte de production de viande résultant de la politique de sédentarisation. Pour maintenir la production de viande bovine par les éleveurs semi-sédentaires il faudrait développer les liens commerciaux régionaux avec les élevages des pays sahéliens.

International audience; Methane (CH4) emission estimations for cattle in Sub-Saharan Africa (SSA) reflect limited production levels and diets that are high in cellulose forage. However, data on these livestock systems is lacking for their accurate evaluation. To provide guidance for climate change mitigation strategies in Senegal, it is necessary to obtain reliable estimates of CH4 emissions from Ndama cattle reared in grazing systems, which is the predominant cattle system in the country. The objective of this study was to determine the annual methane emission factor (MEF) for enteric fermentation of Ndama cattle following the IPCC Tier 2 procedure. Our estimated annual MEF at the herd scale was 30.8kg CH4/TLU (30.7kg CH4/head/yr for lactating cows and 15.1kg CH4/head/yr for other cattle). These values are well below the default IPCC emission factor (46 and 31kg CH4/head/yr for dairy and other cattle, respectively) proposed in the Tier 1 method for Africa. Our study showed that feed digestibility values differ with season (from 46 to 64%). We also showed that cattle lose weight and adapt to lower feed requirements during the long dry season, with a resulting major reduction in methane emissions. The results of this work provide a new framework to re-estimate the contribution of grazing systems to methane emissions in Africa.

Pastoralists make the most of resources distributed unevenly over space and time to provide a range of goods and services. Operating in a shock-prone environment, pastoralists deploy endogenous strategies such as mobility, diversification in agriculture or in non-agricultural activities, management of social networks, etc. However, accurate and reliable knowledge about the economics of pastoralism is yet to be understood and absorbed at the local, regional and national levels, based on reliable data. In the absence of such knowledge, governments and private firms neglect investment that would allow those systems to better connect to markets, and are unable to provide appropriate services, infrastructure and tenure security. With Argentina, Chad and Mongolia as pilot cases, this study by CIRAD, commissioned by FAO, funded by IFAD and facilitated by pastoralist associations (Fundacion Gran Chaco, Reseau Billital Maroobe, and the National Federation of Pasture User Groups), aimed to fulfil this knowledge gap through a multifunctional assessment of pastoral production systems and their economic contribution. Importantly, incorporating self-consumption of pastoralist households' productions themselves as an key component of gross revenue shows a significant increase in their contribution to national GDPs. The diversified sources of revenue and the importance of self-consumption also indicate that pastoral systems fulfil a range of functions (income, food security, flexible labor, etc.). Further, the study promotes close cooperation between pastoralist associations, research institutions and development partners. Such new partnerships allow strengthening the capacity of those pastoralist associations in collecting and managing their own data, as well as using this data in policy dialogue.

International audience; Au Sahel, l’élevage pastoral valorise un milieu extrême. Alors qu’il est accusé d’émettre trop de gaz à effet de serre par kilogramme de lait ou de viande produit, une recherche menée au Sénégal montre que les territoires pastoraux peuvent en réalité avoir un bilan carbone neutre : les émissions d’origine animale sont compensées par la séquestration de carbone dans les sols et la végétation. Ces résultats ont été obtenus par une méthode d’évaluation originale, dite écosystémique : elle intègre l’utilisation du territoire pastoral dans son ensemble, en fonction des saisons et des lieux investis par les troupeaux. Ces résultats incitent à revoir à la baisse les normes actuelles de calcul du comportement alimentaire et des émissions de méthane issu de la digestion des ruminants. D’autres implications sont envisageables, comme améliorer le bilan carbone par des pratiques locales spécifiques et valoriser ces espaces sur le marché du carbone. Préserver ce mode d’élevage est aussi une des voies pour générer du développement et contribuer à sécuriser ces régions.

Dans l’espace ouest-africain, la demande en produits d’origine animale augmente au rythme de la croissance de la population, de l’urbanisation et de l’accroissement des revenus. Cette situation offre un marche potentiel de betail, de viande et de lait. Mais le paradoxe demeure la part de plus en plus croissante des importations extra africaines de produits animaux. L’economie pastorale eprouve des difficultes reelles a faire face a l’accroissement de la demande de viande et de lait dans les pays ouest-africains. C’est pourquoi l’un des defis majeurs auxquels la filiere betail /viande et lait est confronte est d’assurer aux populations un niveau suffisant de consommation de viande et de lait tout en developpant les exportations. Cependant, la Revue Economique Mondiale du Pastoralisme a illustre dans ces travaux l’etat de pauvrete du savoir sur les economies pastorales, le manque de collecte de donnees dans certains pays et l’absence de desagregation des donnees nationales dans d’autres pays. C’est pour contribuer a combler le deficit de savoirs sur les economies pastorales que la presente etude a ete consacree a l’evaluation de la valeur economique de l’elevage bovin au Benin a partir d’un bassin de production. Elle permettra de fournir des chiffres capables de generer des criteres mieux avises pour permettre l’investissement public et la prise de decisions politiques en faveur de l’elevage bovin. Cette etude s’est appuyee sur des enquetes menees au niveau de 52 exploitations d’elevages bovin de deux principaux systemes naisseurs, choisis de maniere raisonnee dans 12 localites representatives de la diversite du bassin de la Donga. La demarche methodologique suivie pour evaluer la valeur economique des productions bovine, se decline en trois etapes : la recension documentaire, l’estimation des productions et leur conversion en valeur monetaire. Au terme de l’evaluation, la valeur economique totale de la production bovine dans le bassin de la Donga, representee par les productions d’animaux sur pied, de viande et de lait, est de un milliard neuf millions quatre cent mille (1 009 400 000) francs CFA. Rapportee a la population du bassin, cette valeur economique de la production bovine est de 4143 FCFA/habitant. Comparee a la valeur totale de production d’aliments en 2012 au Benin qui est de 99000 FCFA/habitant, la valeur de la production bovine represente 4%. Ce resultat met en evidence la faible participation de l’elevage bovin dans la production de l’aliment au Benin. © 2019 International Formulae Group. All rights reserved. Mots cles : Valeur economique, systemes d’elevage, bovin, produits animaux, Benin.

The livestock sector contributes around 14.5 percent of total anthropogenic greenhouse gas (GHG) emissions. Developing mitigation strategies is a serious challenge, especially if we anticipate a rapid growth in the consumption of animal products in Low-Income (LI) and Lower Middle-Income (LMI) countries. Across the planet, livestock systems are highly diverse and the livestock sector offers many possibilities for carbon sinking that can help to reduce emissions. In particular, carbon sequestration in grasslands, rangelands and feed crop fields and manure recycling are crucial in the assessment of the carbon efficiency of livestock value chains. Supporting sustainable livestock production systems, together with sustainable animal product market chains and consumption, requires the completion of GHG inventories based on landscape carbon balances.

International audience; This paper explores an original approach in which greenhouse gas (GHG) emissions and carbon (C) accumulation are assessed monthly and at landscape scale to account for the highly seasonal monsoon climate and the mobility of pastoral herds that characterize West African pastoral ecosystems. The study was conducted in northern Senegal, in the service area of the Widou Thiengoly borehole, a circular zone of 706 km(2) centered on the borehole. The C balance was calculated using an ecosystem approach, i.e. taking all main sources of GHG emissions and C sinks of the ecosystem, not only anthropogenic sources, into account. The annual C balance of the pastoral ecosystem was -0.04 +/- 0.01 tC-eq.ha(-1).year(-1), showing that total GHG emissions were mitigated by C accumulation in trees, soil and livestock. The C balance varied considerably with the seasons, with a positive monthly balance in the wet season, from July to October (+ 0.58 tC-eq.ha(-1).month(-1)) and a negative monthly balance in the cold dry season from November to February and the hot dry season from March to June (- 0.57 and -0.05 tC-eq.ha(-1).month(-1) respectively). Care should be taken when generalizing these results, which were obtained in a dry year, because of strong inter-annual variations in rainfall.

The above-ground biomass and floristic composition of Butana rangelands in Sudan were assessed in 2006 with field surveys covering 25 sites. The remote sensing data derived from Spot image for the same period was integrated to the field surveys to map the spatial distribution of biomass production (kg ha-1) using the perpendicular vegetation index. A rainfall map of the region was established from the meteorological data of the season and the digital elevation model. The rain use efficiency factor, which is the quotient of the annual pri­mary production (kg dry matter ha-1) of a season by rainfall (mm) of the same season, was used as a rangeland degradation and desertification indicator in Butana. To test the potential of water harvesting techniques on biomass produc­tion, two seasons’ experiments were conducted (2006 and 2007). Their results were used to simulate the potential of biomass production with water harvest­ing application through a general model that linked remote sensing output, field measurement and water harvesting results.

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International audience; The feeding behavior and fodder intake of cattle, sheep and goats grazing semi-arid sub-Saharan Africa rangelands in Senegal was studied over a one-year cycle. The objective of the study was to improve the assessment of fodder intake by livestock grazing rangelands in semi-arid sub-Saharan Africa, The study was conducted in the service area of a borehole that includes 354 pastoral settlements and a total of 11,000 cattle and 1800 small ruminants. The grazing behavior of five steers was monitored monthly. Their forage intake was estimated every month from hand plucking simulations of all the bites of forage taken by the steers 24 h out of 48. The feces they excreted during the day were collected in fecal bags. Near infrared spectrum (NIRS) images were used to analyze 80 samples of these feces, and the data were then added to an existing reference data set to predict fodder intake and digestibility using NIBS. The complete and contextualized data base was then used to predict the daily fodder intake and its digestibility by cattle, sheep and goats whose fresh feces were systematically and randomly sampled every month in the study area (768 samples). Annual means of the daily dry matter fodder intake were 68.4 +/- 6.4 g/kg LW0.75 or 17.2 +/- 1.7 g/kg LW for cattle, 73.1 +/- 5.3 g/kg LW07.5 or 34.3 +/- 2.8 g/kg LW for sheep, and 74.7 +/- 8.7 g/kg LW0.75 or 37.1 +/- 4.4 g/kg LW for goats. The annual mean organic matter digestibility of grazed fodder was higher for goats (67.4 +/- 3.9%) than for sheep (64.1 +/- 3.2%) and cattle (59.3 +/- 3.8%). The seasonal variations in diet digestibility were bigger for cattle than for sheep, and smaller for goats. The standard reference used to assess livestock fodder intake in tropical Africa relies on a fixed daily intake rate per unit live weight of 25 g/kg LW. Our results show that this method overestimates (+ 45%) intake by cattle, especially in the dry season, and underestimates intake by small ruminants (-24%). Alternative assessment methods are proposed either relying on a single standard annual intake per metabolic weight unit for all ruminant species, 73 g/kg LW0.75 per day, or on separate annual intake norms per live weight unit for cattle (18 g/kg LW per day) and small ruminants (34 g/kg LW per day). In both cases, modulations (+/- 12%) of the norm are proposed for use in the wet and dry season.

International audience; Enteric methane is one of the main sources of Green House Gaz produced by ruminant livestock. Traditional pastoral systems use local natural grassland resources for livestock feeding, including a wide diversity of ligneous forages browsed by ruminants in West Africa. However few studies assessed the methane emissions of such forages. This study analyzed a large collection of ligneous and herbaceous forages, looking for estimating their methanogenic potential by using their biochemical composition predicted by NIRS and two models available in the literature (Sauvant et al. 2011, Jayanegara et al. 2012). Results showed a higher CH4 production in ligneous forages and tropical grasses when compared to tempered grasses (+10.3 vs+7.0 % respectively). However, ligneous forages contain some tannins at higher concentrations, which according to the models would tend to decrease the methanogenic potential (-16.8% and -2.3%), thus nuancing the first methane emissions results.; Le méthane entérique, représente une source importante de Gaz à effet de serre générés par l’élevage. En Afrique de l’Ouest les systèmes pastoraux traditionnels utilisent essentiellement les ressources herbacées naturelles, et périodiquement les fourrages ligneux, pour lesquels les niveaux d’émissions de méthane sont peu connus. Dans une approche prospective l’étude capitalise une importante base de données de fourrages ligneux et herbacés, dont la composition chimique a été prédite par SPIR et le potentiel méthanogène calculé selon les modèles de Sauvant et al. (2011) et Jayanegara et al.( 2012). Les résultats révèlent que les fourrages ligneux et les graminées tropicales ont tendances à émettre en moyenne plus de CH4, que les graminées tempérées (+ 10.3 et + 7.0 %). Toutefois lorsqu’elle est prise en compte leur teneur en tanins contribuerait à réduire la production potentielle de CH4 (16.8% et 2.3 %respectivement) nuançant les émissions potentielles de méthane.

Greenhouse gas (GHG) emissions from the surface soils and surface water receiving animal excreta may be important components of the GHG balance of terrestrial ecosystems, but the associated processes are poorly documented in tropical environments, especially in tropical arid and semi-arid areas. A typical sylvo-pastoral landscape in the semi-arid zone of Senegal, West Africa, was investigated in this study. The study area (706 kmA(2) of managed pastoral land) was a circular zone with a radius of 15 km centered on a borehole used to water livestock. The landscape supports a stocking rate ranging from 0.11 to 0.39 tropical livestock units per hectare depending on the seasonal movements of the livestock. Six landscape units were investigated (land in the vicinity of the borehole, natural ponds, natural rangelands, forest plantations, settlements, and enclosed plots). Carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes were measured with static chambers set up at 13 sites covering the six landscape units, and the 13 sites are assumed to be representative of the spatial heterogeneity of the emissions. A total of 216 fluxes were measured during the one-year study period (May 2014 to April 2015). At the landscape level, soils and surface water emitted an average 19.8 t C-CO2 eq/(hm(2).a) (CO2: 82%, N2O: 15%, and CH4: 3%), but detailed results revealed notable spatial heterogeneity of GHG emissions. CO2 fluxes ranged from 1148.2 (+/- 91.6) mg/(m(2).d) in rangelands to 97,980.2 (+/- 14,861.7) mg/(m(2).d) in surface water in the vicinity of the borehole. N2O fluxes ranged from 0.6 (+/- 0.1) mg/(m(2).d) in forest plantations to 22.6 (+/- 10.8) mg/(m(2).d) in the vicinity of the borehole. CH4 fluxes ranged from-3.2 (+/- 0.3) mg/(m(2).d) in forest plantations to 8788.5 (+/- 2295.9) mg/(m(2).d) from surface water in the vicinity of the borehole. This study identified GHG emission "hot spots" in the landscape. Emissions from the surface soils were significantly higher in the landscape units most frequently used by the animals, i.e., in the vicinity of the borehole and settlements; and emissions measured from surface water in the vicinity of the borehole and from natural ponds were on average about 10 times higher than soil emissions.

Methane emission from ruminants is scarcely evaluated in African pastoral systems. Intake and proportions of the different plants composing the diet under such systems vary highly along wet and dry seasons, which may affect methane production. This study took place in a semi-arid Sahelian location of Senegal (27.8°C average temperature and 393 mm annual rainfall). In each of two different sites, three Gobra zebus were tracked throughout one year. A representative sample of their global diet was obtained one day per month by the simulated bites technique. Diet was mainly made of grasses, herbaceous legumes, tree and shrub foliage and pods, and “straw” defined as dried standing forage and plant residues. Methane production and volatile fatty acids (VFA) concentrations were determined using an in vitro batch fermentation system. Neutral detergent fibre was measured by near infrared spectrophotometry. Methane production varied between 24.2 and 35.2 mL/g forage dry matter (DM) according to months, was minimal in August (rainy season) and maximal in February (dry season). The acetate:propionate ration varied as methane (3.2 and 4.8 in August and February, respectively); VFA production was minimal in March and maximal in October (64.3 and 81.2 mmol/L, respectively). Methane production was closely related to dietary NDF content (r=0.88) and acetate:propionate ratio (r=0.96). Variation between animals was partly explained by dietary NDF content, and was reduced when methane was expressed in mL/g NDF. For six successive periods (February to July) and for the same animal, plant categories constituting the diet were incubated separately. Reconstituting the production of methane and VFA in the diet based on the proportion of plant components gave similar values to those of the global diet (33.9 and 33.7 mL methane /g DM and 74.0 and 77.7 mmol VFA/L, respectively). This suggests the absence of interaction on rumen fermentation between plant categories. (Texte intégral)

Nous presentons une procedure permettant de preciser une strategie de mobilisation de l'information pour l'aide a la decision et l'illustrons avec le cas d'un systeme d'information (SI) sur le pastoralisme au Sahel (SIPSA). Dans cette approche experimentale, nous considerons des produits d'information possibles du SIPSA (indicateurs, documents, cartes) comme des donnees subjectives et testons, avec les utilisateurs cibles, leur potentiel d'appui au traitement de questions de developpement. Nous appliquons la methodologie Q pour faire emerger : a) la valeur percue de l'information, ses specificites et ses apparentes contradictions, et b) une typologie des utilisateurs, leurs ressemblances et leurs differences concernant la mobilisation de l'information. L'analyse des resultats a des implications operationnelles pour la conception et la strategie de mise en oeuvre d'un SI. En effet, la methode proposee vient faciliter un travail reflexif ex-ante sur la pertinence des indicateurs, l'ergonomie du SI, le ciblage et la formation des utilisateurs, et apporte des elements objectifs pour etablir la composition d'un kit minimum de donnees et de produits d'information utiles.

L’état actuel des paysages et des territoires sahéliens est la résultante d’interactions entre facteurs écoclimatiques, socio-économiques et politiques, à l’oeuvre depuis plus de quatre décennies. Au nord du Sénégal, l’espace géographique du Ferlo est représentatif d’une cohabitation entre des systèmes de production agrosylvopastoraux dans laquelle l’activité pastorale se maintient en compétition avec les autres, car les complémentarités anciennes entre systèmes de production agricoles et pastoraux, ou entre pasteurs et collectivite ´, tendent à se dégrader sous la pression foncière. Ces forces de pression aux intérêts quelques fois divergents ont comme indicateurs de transformation tangibles : la conversion socio-économique et environnementale ; la pluralité des modes d’accès à la terre en dehors du cadre légal ; les litiges et difficultés dans l’affectation des terres ; la fragmentation des paysages ; la restructuration agricole et pastorale des territoires. C’est aussi dans ce contexte que les politiques de décentralisation et d’aménagement du territoire ont transféré aux collectivités territoriales le pouvoir d’administrer, d’exploiter et de gérer les ressources naturelles et le foncier, afin de renforcer la gouvernance locale et de répondre aux enjeux de développement durable des systèmes de production. L’expé- rience présentée ici traite du processus de coconstruction et de mise en oeuvre d’un outil de simulation pour accompagner et instruire les prises de décision des collectivités locales chargées de l’application de la loi sur le domaine national. Les différentes étapes de cette démarche participative qui ont conduit à la conception, au test et à l’évaluation par les utilisateurs du modèle AIDA et de ses scénarios sont présentées., The present state of the landscapes and territories in the Sahel is the result of interactions between climatic, economic, social and political factors which have been taking place for more than four decades. In the north of Senegal, the Ferlo geographical space is representative of cohabitation between sylvopastoral and agricultural production systems, within which the pastoral activity is maintained under conflictual conditions as traditional complementarities between agricultural and pastoral production systems, or between pastors and communities, tend to deteriorate under land pressure. Such pressure operates for a variety of often divergent goals displaying tangible transformation indicators with social economic and environmental conversion such as illegal land access plurality, disputes and trouble in land allocation, landscape fragmentation and agricultural territory and pastoral restructuring. It is also within this framework that territory decentralisation and development policies have transferred to stakeholders the power to administer, exploit and manage natural resources and lands under their jurisdiction so as to strengthen local governance and respond to sustainable development needs of production systems. The experiment shown in this case study deals with the process of co-building and setting up tools and simulation models in order to accompany and instruct decision making by local communities responsible for applying the law 64-46 of 06 June 1964. The different steps of this participative approach leading to the “AIDA” agent model design and scenarios have been put forward, tested and evaluated by the users.

International audience; The future of pastoral systems and their interactions with territories are the subject of considerable debate in the scientific literature and are still insufficiently documented. Assessing the sustainability of pastoral systems and their interactions with the sustainability of territories is thus a complex task. We proposed in this study a method to assess the sustainability of pastoral systems within their territories. After reviewing the literature, we conducted interviews with pastoralism experts in France and in Africa on the subject of sustainability in general and pastoral systems in particular. We designed our grid according to the principles-criteria-indicators approach and included 10 principles grouped into three major fields: ‘Availability of resources in the territory’, ‘Properties of the system’, and ‘Extended sustainability’. Understanding the strategies used in pastoral systems enabled us to propose a set of specific criteria per principle. Finally, we compared our grid with other methods used to assess sustainability.; El futuro de los sistemas pastoriles y sus interacciones con territorios son el foco de un debate considerable en la literatura científica y se encuentran aún insuficientemente documentados. Asesorar la sustentabilidad de los sistemas pastoriles y sus interacciones con la sustentabilidad de los territorios es por lo tanto una tarea compleja. Proponemos en este estudio un método para asesorar la sustentabilidad de los sistemas pastoriles dentro de sus territorios. Después de revisar la literatura, condujimos entrevistas con expertos en pastoreo en Francia y África sobre el tema de la sustentabilidad en general y en sistemas pastoriles en particular. Diseñamos nuestra cuadrícula según un enfoque en los principios-criterios-indicadores e incluimos 10 principios agrupados en tres campos mayores: la disponibilidad de los recursos en el territorio, las propiedades del sistema y la sustentabilidad duradera. Comprender las estrategias utilizadas en los sistemas pastoriles nos permitió proponer un set de criterios específicos por principio. Finalmente comparamos nuestra cuadrícula con otros métodos utilizados para asesorar la sustentabilidad.; L’avenir des systèmes pastoraux et leurs interactions avec les territoires sont au coeur de débats majeurs dans la littérature scientifique et sont encore insuffisamment documentés. Evaluer la durabilité de ces systèmes pastoraux et leurs interactions avec la durabilité des territoires est donc une tâche complexe. Nous proposons dans cette étude une méthode pour évaluer la durabilité des systèmes pastoraux dans leurs territoires. Suite à un travail de synthèse bibliographique, nous avons conduit des entretiens auprès d’experts du pastoralisme en France et en Afrique sur le sujet de la durabilité de manière générale et de celle des systèmes pastoraux en particulier. Nous avons conçu une grille sur la base de l’approche principes-critères-indicateurs, en incluant 10 principes autour de trois thèmes majeurs que sont la disponibilité des ressources dans le territoire, les propriétés des systèmes, et la durabilité étendue. La compréhension des stratégies utilisées dans le cadre de l’activité pastorale nous a permis de proposer un jeu de critères spécifiques par principe. Enfin, nous discutons de cette nouvelle méthode au regard d’autres méthodes utilisées pour évaluer la durabilité.

In Sahel, land and resources are used, according to the seasons, by various actors with interests sometimes difficult to conciliate. This spatial competition for the access to the natural resources induces a set of processes leading to overgrazing and conflicts for the access to water. In such a complex agro-sylvo-pastoral context, acquiring and formalizing knowledge about the practices and rules which govern the system are essential to help and accompany the rural populations towards the sustainable management of their environment. Among the new modelling tools coming from the field of Artificial Intelligence, Agent-Based Models (ABMs) are now widely used to tackle the issue of integrated natural resource management. The increase in popularity of ABMs is partially due to their intelligibility, not only by scientists from various research fields, but also by stakeholders. It then becomes easier to build an understandable representation of the system as an "artificial world" and to perform simulations in order to collectively test and discuss various scenarios about the resource management. This paper describes an ABM which has been designed to formalize the interactions between the biophysics dynamics of the natural resources and the socio-economic factors driving the land-use dynamics around the drilling of Thieul village in the sylvo-pastoral area of Ferlo (Senegal). The first results show that rainfall still plays an extremely significant role in the pastoral system despite the drilling of boreholes. Paradoxically, steady rainfall over long periods of time can lead to negative effects on the relations between herders and farmers. (c) 2005 Elsevier Ltd. All rights reserved.

International audience; This study aimed to determine the relationships between N'Dama cows body condition score (BCS) and (i) calf growth and the milk collected; and (ii) the probabilities of pregnancy and juvenile mortality. Animals from 10 herds ranging from 20 to 210 animals in herd size were followed monthly in an extensive range management system in Southern Senegal between 1993 and 1998. For daily weight gains and milk collected, linear mixed-effects models were fitted between calving and 6 months postpartum. Cow lactation was included as random effect, with an unstructured variance–covariance matrix. Calving season, parity, herd size, and calving BCS were the fixed effects. For the probabilities of pregnancy and juvenile mortality, survival models for grouped data were fitted on a monthly scale. The model selection was based on the Akaike information criteria. In large herds, calving BCS had little effect on milk production. In small herds, calves born to cows scoring ≥2.5 points at calving grew quicker and their dam were more milked. The relative difference in milk production between thin and fat cows averaged 23%. The relative gain was higher in the cool dry season than in the other seasons, and for primiparous than for multiparous cows. Except during the hot dry season, the probability of pregnancy was twice as high for cows scoring ≥2.5 points the two previous months than for other cows. The BCS had no effect on calf survival until 1 year of age in large herds. In small herds, calves born to thin cows at calving showed a survival at 1 year more than five points lower than calves born to fatter cows. The threshold of 2.5 points on a five-point scale is pertinent to describe the production performance of N'Dama cows in such a breeding context

ORSTOM, Inst Res & Dev, Dakar, Senegal; Inst Forestry Agr & Environm Engn, ENGREF, F 34033 Montpellier 5, France; ISRA, LNERV, EMVT, CIRAD,ECONAP, Dakar, Senegal; Projet Concerte Rech & Dev Elevage Afrique Ouest, CIRDES, Bobo Dioulasso, Burkina Faso; USP, Inst Res & Dev, CENA, Ex ORSTOM, BR 13400970 Piracicaba, SP, Brazil; International audience; The viability of mixed farming systems in West African savannas relies largely on the management of endogenous organic resources. Assessment of the organic balance at both plot and village territory scales is needed as an indicator of this viability. Distribution of carbon (C), nitrogen and phosphorus in soil and plant biomass was thus quantified for a village in southern Senegal across the different land use systems (LUS) and farm holdings. The village exhibited ring-like organisation, including a compound ring, a bush ring, and lowland paddy fields, with positive gradients of intensification and food production from the savanna to the dwellings. Marked contrasts were found between holdings, especially in livestock availability. Clear relationships were evidenced between the spatial distribution of C and nutrients and the agricultural functions of LUS and holdings, while multi-scale diversity appeared to be the main factor that ensured the functioning of the system. Intensification schemes at the village level aimed at increasing organic resources and their cycling efficiency must thus take into account their impact on this diversity. (C) 2003 Elsevier Ltd. All rights reserved.

Numerous territories of Sub-Saharan Africa are composed of a mosaic of very different landscape units: cropland, forest, and savannah. This spatial, but also temporal heterogeneity leads to complexity in the analysis of cattle intake behaviour. The instantaneous intake rate (IIR) is generally analysed in relation to forage biomass density (Bm), i.e. the functional response. We analysed the relationship between IIR and Bm and effects of other vegetation and animal factors for two herds of N’Dama cattle grazing freely during the dry season in the complex Sare Yoro Bana landscape located in the Kolda region in Southern Senegal. The available forages included crop residues (from rice, millet and maize), grass and hay, fruits and litter. The amount and quality of biomass declined throughout the dry season. The variation in IIR was large and could be attributed to differences in Bm (for 30%) and differed between seasons and vegetation types (also 30% of variation explained). Effects of animal characteristics such as wither height and requirements were significant but small compared to herbage-related factors. In the middle of the dry season (MDS) the IIR was higher than in the early dry season (EDS), probably due to better herbage prehensibility, whereas in the late dry season total herbage stocks were very low and also IIR was lower than in EDS and MDS. Two different relations were observed between IIR and the bite rate. In the EDS higher bite rate resulted in higher IIR, compared to an absence of such effect in later stages of the season indicating a compensation between ingestion rate and bite size. Based on these result, we conclude that the relation between intake rate and biomass density generally follows a type-2 functional response, modelled by a monotonically saturating function, but is strongly affected by many factors related to herbage palatability. Despite the inherent spatio-temporal complexity of the vegetation and the challenges in observations and data collection these relationships can be quantified for cattle grazing in a heterogeneous semi-arid landscape.

L'estimation de la densite des ligneux dans les savanes est une etape souvent necessaire dans l'etude de la production de ces pâturages. L'experience a montre que les observations directes par denombrement donnaient souvent des valeurs differentes de celles qui sont obtenues par les methodes PPI (plus proche individu) et QCP (quadrant centre sur un point) de la Plot-less method. Les auteurs montrent que ces divergences sont liees a l'heterogeneite de la repartition des individus dans l'espace. (Resume d'auteur)

Le pastoralisme joue un rôle prépondérant dans l'économie des pays du Sahel et de l'Afrique de l'Ouest (AO) et participe à la sécurité alimentaire et nutritionnelle des ménages ruraux et urbains (Wane et al., 2009). La contribution du secteur élevage au PIB atteint 5 à 10% et les systèmes pastoraux fournissent plus de 50% de la production en viande et en lait (De Haan et al., 1999). Le pastoralisme s'avère économiquement viable et écologiquement adapté à la valorisation durable d'une ressource naturelle fragile et éparse dans la zone sahélienne (Toutain et al. 2012). Plus encore, le système de production mobile fournit de meilleurs rendements en termes de production annuelle de protéines animales par hectare par rapport au système de ranching ou autres systèmes intensifs à vocation commerciale. Ces systèmes d'élevage sont confrontés à de nombreux défis, liés notamment, à la marginalisation des populations pastorales dans les instances de gouvernance locale, et à la compétition croissante pour l'accès aux ressources. Dans ce contexte, les pasteurs et les politiques manquent d'informations et d'indicateurs spécifiques sur les enjeux et la viabilité de ce système de production (flux saisonniers de transhumance, vulnérabilité des ménages pastoraux, variations des prix des animaux et de denrées alimentaires¿) insuffisamment pris en compte par le cade des systèmes d'information et d'alerte précoce sur la sécurité alimentaire existants (Touré et al 2012). A cette asymétrie d'informations s'ajoute l'absence de cadre officiel de concertation entre les pasteurs, leurs organisations de producteurs faitières et les institutions techniques nationales, régionales et internationales en charge des politiques agricoles en général et de sécurité alimentaire et nutritionnelle des populations pastorales en particulier. Partant des enseignements tirés de la mise en oeuvre du système d'information sur le pastoralisme au Sahel (SIPSA) dans six pays du CILSS (Burkina, Mali, Mauritanie, Niger, Sénégal et Tchad). Cette présentation va mettre en exergue ses acquis (scientifiques, méthodologiques, pédagogiques¿ ), ses limites et ses défis (structurels, politiques..) en vue d'une amélioration des interventions publiques en période de crise.

La survie et la germination des graines de sept espèces de légumineuses ligneuses (A. nilotica adansonii, A. raddiana, A. senegal, A. seyal, B. rufescens, F. albida et P. juliflora) ont été étudiées après ingestion et excrétion par des bovins, des ovins et des caprins. Cette étude montre que : - les graines dures restent intactes et conservent leur viabilité après excrétion par les ruminants domestiques alors que les graines aux téguments perméables sont détruites; - les bovins excrètent significativement plus de graines intactes que les petits ruminants. Cette différence semble liée essentiellement à l'activité masticatoire plus importante chez les ovins et les caprins; - la germination des graines dures n'est pas améliorée après passage dans le tractus digestif des ruminants. Au total, l'ingestion par les ruminants domestiques ne peut être considérée comme un facteur favorisant la levée de dormance des graines dures, mais seulement comme un moyen de dissémination de graines intactes.

Les ruminants, du fait de leur processus de digestion des aliments, produisent du CH 4 . Notre objectif dans cette etude, est d’obtenir des donnees sur la qualite des regimes alimentaires du cheptel sahelien et la relation entre celle-ci et la production de methane. Pour cela, des donnees ont ete collectees d’octobre 2013 a septembre 2014 sur trois vaches suivies a Niassante (village d’eleveur) et trois taurillons au centre de recherches zootechnique de Dahra. Les echantillons de feces et de regimes preleves ont ete ensuite tries par groupes botaniques, peses, seches, broyes et analyses par SPIR. La digestibilite de la matiere organique (dMO) et la production de methane ont ete calculees a partir des equations de prediction. La dMO est de 51,26 ± 1,35% a Niassante et 52,62 ± 3,28% a Dahra. La saison de collecte du regime affecte significativement la dMO (p = 0,000). La production de CH 4 est en moyenne de 75 litres/jour/animal et est significativement affectee par la periode de l’annee (p= 0,000) et la quantite de matiere seche ingeree. Elle est negativement affectee par la dMO des regimes ingeres par les bovins (r = -0,308 ; p = 0,013). Il serait donc interessant de bien caracteriser les ressources fourrageres utilisees par nos animaux et de determiner leurs valeurs alimentaires. © 2016 International Formulae Group. All rights reserved. Mots cles: Digestibilite, regime alimentaire, emission methane, Zebu Gobra English Title: Estimation of digestibility variability and methane (CH 4 ) emission of ruminants diets depending on the season in Sahelian pasture English Abstract Ruminants, due to their food digestion process, produce CH 4 . Thus, the objective of this study is to obtain data on quality of Sahelian animals’ diets and the relationship between it and the production of CH 4 . For this, data were collected from October 2013 to September 2014 in three cows followed at Niassante (a village of farmer) and three bulls at livestock research center of Dahra. Feces samples taken and collected diet were then sorted by botanical groups, weighed, dried, crushed and analyzed by NIRS. The organic matter digestibility (OMD) and methane production were calculated from prediction equations. The OMD is 51.26 ± 1.35% to Niassante and 52.62 ± 3.28% to Dahra. The collected diet according the season has significant effects on the OMD (p = 0.000). CH 4 production is on average of 75 liters/day /animal and is significantly affected by the period of year (p = 0.000) and the amount of ingested dry matter. It is negatively affected by the digestibility of the organic matter ingested by cattle (r = -0.308; p = 0.013). It would be interesting to characterize forage resources used by animals and determine their dietary values. © 2016 International Formulae Group. All rights reserved Keywords: Digestibility, diet, methane emission, Gobra Zebu

Communication en libre accès, document est disponible en ligne : http://www.google.fr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDAQFjAA&url=http%3A%2F%2Fwww.au-ibar.org%2Fcomponent%2Fjdownloads%2Ffinish%2F86%2F1619&ei=9KE6U8imG8nH0QWt54HADw&usg=AFQjCNH3UAWZcijWK8vsdCwfVCjyIGNCoQ; National audience

agr.2011.0480 Auteur(s) : Christine Silvy Avec la collaboration de : Jean-Yves Jamin, Sami Bouarfa et Jean-Christophe Poussin Theme choisi pour ce numero : Agricultures irriguees Selection de sites SITES « EAU » • Conseil mondial de l’eau (CME) www.worldwatercouncil.org/ Le Conseil mondial de l’eau, une plate-forme internationale multiacteurs. Il a ete cree en 1996 en reponse aux preoccupations croissantes de la communaute internationale face aux problematiques [...]

Depuis plus d’une décennie, la globalisation des enjeux environnementaux, économiques et sociaux induit de rapides transformations du monde agricole et des territoires ruraux. Celles-ci posent en particulier la question de l’avenir des systèmes d’ élevage extensifs, face au défi du doublement attendu des productions animales d’ici 2050, tout en préservant l’environnement. Afin de mieux comprendre et accompagner ces processus de transformation, une analyse comparative des dynamiques des systèmes d’élevage et des territoires a été réalisée à partir de sept études de cas sur trois continents sur la base d’une grille de lecture commune. Les facteurs globaux (démographie, environnement, marchés) pèsent sur l’ensemble des territoires d’élevage, mais leurs impacts sont modulés de manière spécifique par des facteurs locaux : culture, histoire, enclavement, projets locaux et politiques publiques. Cependant les processus de transformation sont comparables et l’élevage extensif est souvent sous pression, notamment foncière et économique, face aux activités alternatives qui se développent sur les territoires d’élevage. Pour évaluer équitablement et de façon intégrée le rôle de l’ élevage dans le développement des territoires, il est nécessaire de mieux qualifier et de quantifier ses différentes fonctions qui sont complexes car multi- échelles sur les plans spatial et temporel., For over a decade, the globalisation of environmental, economic and social issues has induced rapid modification in agriculture and land. These changes raise the question of future extensive livestock systems in regards to the worldwide challenge to double livestock production by 2050 in ways which are safe for the environment. In order to better understand and follow modification processes, a comparative study of livestock systems and land dynamics has been carried out on seven case studies on three continents through the use of a common grid. Global factors (demography, environment, markets) are active on all livestock lands but their impacts are modulated and specific in relation to local factors (culture, history, isolation, local projects, public policies). Be that as it may, modification processes are similar and livestock production most often appears to be under pressure from alternative land-uses, especially for land-tenure and economic factors. To estimate livestock’s role in land development with equity and in an integrative way, it is necessary to improve qualitative and quantitative assessment of livestock functions which are complex due to spatial and temporal multi-scale processes.

Auteur(s) : Benoit Dedieu1,5, Annick Gibon2,6, Alexandre Ickowicz3,6, Jean-Francois Tourrand4,6 1InraUMR 1273 MetafortTheix 63122Saint Genes ChampanelleFrance 2InraUMR 1201 DynaforBP 52627F-31326 Castanet-Tolosan cedexFrance 3CiradUMR 84 ERRCMontpellier Supagro2, place Viala34060 Montpellier CedexFrance 4CiradIFRAI GIP Inra-Cirad42, rue Scheffer75116 ParisFrance 5Benoit [...]