Factors affecting feed intake, energy expenditure and work output of oxen and bulls used for draught purposes in semi-arid West Africa

The objectives of this thesis were to i) determine the energy expenditure of draught oxen performing common farm operations, ii) establish the relationships between work on intake and digestibility of feeds by draught oxen, iii) investigate the effect of body condition before work and live weight losses during work on work output, and iv) investigate the implications of heat stress on draught oxen in semiarid areas. The ultimate aim of this study was to generate information necessary for the design of feeding and working strategies for draught animals in semi-arid areas. To meet these objectives four experiments were conducted at the ICRISAT Sahelian Centre, with the collaboration of the International Livestock Centre for Africa.In the first experiment the Oxylog, a portable breath by breath gas analyser, was used on 7 animals to determine their standing metabolic rate, their energy cost of walking on soils of different consistencies, and their efficiency of doing work, i.e., ploughing and carting. The average standing metabolic rate of animals was 487 (±10.6) kJ/kg LW0 75. The consistency of the soil on which animals were working had a marked effect on their energy cost of walking which was 1.59 (±0.069), 2.15 (±0.084) and 1.0 (±0.10) J/m/kg live weight on unploughed land, ploughed land and laterite tracks, respectively. The efficiency of ploughing sandy soils was 0.32 and was not significantly different from the efficiency of carting with different loads. The efficiency of doing work was not influenced by the type of work performed, the draught force exerted or the walking speed.In the second experiment intake of millet stover, water intake, live weight, plasma concentrations of T3, T4 and urea-nitrogen were measured on 18 animals that worked for 0, 2 or 4 h/day in sequence during three 3-week experimental periods. In addition to these variables, the digestibility and rate of passage of feeds through the digestive tract were measured during the third experiment on 12 animals working either 0, 2.5 or 5 h/day in sequence during three 2-week experimental periods. In the fourth experiment feed intake was measured on 18 animals of different body condition that worked 4 days a week for 7 weeks. The absence of effect of work on intake of millet stover was consistent during these experiments. The efficiency of utilisation of eaten roughages and the rate of passage of the digesta in the gastro¬ intestinal tract were not influenced by work either. This suggest that the nutrient supply from intake of roughages by working oxen and bulls is unlikely to be sufficient to compensate for the extra energy expended during work. Feed intake was however significantly affected by the quality of the millet stover fed and by the body condition of the animal. The level of intake of millet stover was proportional to the amount of leaves in the stover. Animals in bad condition ate more millet stover than animals in good body condition. Feed intake improved also as work progressed in the second and third experiment. Because animals could not increase feed intake they mobilised their body reserves to perform work. Hence body weight losses were seen during all experiments. Animals consumed more water on working days than on days they were at-rest in the shade. Rectal temperature, respiration rate, climate parameters and work output were measured during the second, third and fourth experiments. The heat stress that working animals were subjected to did not interfere with their digestive physiology, however it negatively affected their work performance. Repeatability estimates were 0.19 for rectal temperature before work, 0.29 for the maximum increase in rectal temeperature during work, and 0.16 for rectal temperature during work. There was a marked variation in the capacity of individual oxen to cope with heat stress. Fatter animals had more difficulties in maintaining homeostasis than leaner animals.In the fourth experiment 18 oxen were allotted to 3 treatment groups according to their body condition: poor, medium and good. Work performance, speed of work and weight losses were measured during 7 weeks when animals worked 4 days/week pulling loads equivalent to 12.5 kgf/100 kg live weight. Work performance was more dependent on live weight than on body condition. Also live weight losses did not negatively influence work performance. Power output improved during the course of the experiment while animals were undergoing weight losses

Relations à distance des migrants et réseaux d'insertion à Dakar

Dans cet article sur les relations à distance des migrants vis à vis de leur milieu d'origine, l'auteur aborde sucessivement les types de visite des migrants et des migrantes selon leur âge dans leur localité d'origine, les dons par génération, sexe et statut de migrant ou non au noyau familial ou aux parents, le recours à un intermédiaire ou à la parenté pour trouver un logement, le premier emploi. Il insiste sur le fait que la permanence des réseaux d'origine n'a d'égale que la vitalité des réseaux sociaux urbain

Crise de l'agriculture africaine

Cette analyse des réseaux migratoires Sereer permet de retenir : le déplacement de la force de travail et donc la redistribution des ressources humaines qui découle des migrations; le village et la ville sont des espaces d'expression des filières migratoires; l'individu et la famille participent selon son statut à l'élaboration de stratégies migratoires. Tout laisse à croire que les flux migratoires Seerer vers Dakar iront en s'accentuant. Les familles préconisent la migration comme solution à la crise de l'agricultur

La gouvernance multidimensionnelle et la reconfiguration des interactions entre les États et les mouvements citoyens en Afrique de l’Ouest et du Centre (Essai)

Cet essai vise à démontrer que, d’une part, l’échec des approches prescriptives des institutions de régulation internationale et, d’autre part, l’affirmation de mouvements citoyens sous la bannière altermondialiste ont pour conséquence d’accélérer l’exigence d’une gouvernance ouverte en Afrique. C’est ainsi que plusieurs acteurs de la société civile font l’apprentissage de la coproduction des politiques publiques avec les États. Ce type de gouvernance multidimensionnelle favorise des interactions horizontales et verticales entre plusieurs catégories d’acteurs et participe à reconfigurer les relations de défiance et d’évitement classique entre les États, les mouvements sociaux et le secteur privé. L’auteur attire cependant l’attention sur le fait que si les mouvements citoyens prônent des approches ascendantes, leurs interlocuteurs ne sont pas prêts à leur concéder une remise en cause intégrale du paradigme néolibéral, qui fonde les initiatives de développement destinées à l’Afrique et dont les limites sont analysées dans cette contribution.The aims of this essay are to demonstrate the failure of the prescriptive discourse held by international regulatory institutions and to point up to the emergence of movements which, under the alter-globalization banner, are contributing to a growing claim for open governance in Africa. Actors from the civil society are actually learning to co-produce public policies with the State. This type of multidimensional governance favour horizontal as well as vertical interactions between different categories of actors and contribute to the reconfiguration of the relations between the State, social movements and the private sector, which were typically based on distrust and avoidance. The author, nevertheless, underlines that even when citizen movements promote ascending dynamics, their counterparts are not ready to give up completely the neoliberal paradigm which is still the backbone of development initiatives projected for Africa. Their limits are discussed in this contribution.Este ensayo trata de demostrar que el fracaso de los enfoques normativos de las instituciones de regulación internacional, por una parte, y que la afirmación de los movimientos ciudadanos bajo la insignia altermundialista, por otra parte, han acelerado la demanda de una gobernanza abierta en África. De ahí que algunos actores de la sociedad civil se ejerciten en la co-producción de políticas públicas con los Estados. Este tipo de gobernanza multidimensional favorece las interacciones horizontales y verticales entre diferentes categorías de actores y participa en la reconfiguración de las relaciones de desconfianza y desvío clásico entre los Estados, los movimientos sociales y el sector privado. El autor llama la atención sobre el hecho de que si bien los movimientos ciudadanos preconizan enfoques ascendentes, sus interlocutores no están dispuestos a concederles un replanteamiento total del paradigma neoliberal en el que se basan las iniciativas de desarrollo destinadas a África y cuyos límites analizamos en ésta contribución