Evaluation technique et economique des formules alimentaires de blocs multi nutritionnels d’embouche ovine au Niger

L’essai conduit en 75 j à la station de recherche de Kollo visait l’évaluation des performances de croissance des béliers nourris avec 5 formules alimentaires à base des ressources locales associées au tourteau de coton et son de blé. Le matériel biologique était constitué de 50 béliers de race Ara-Ara, âgés de 18 à 24 mois et de poids moyen de 25,00 ±3,02 kg. Les rations ont été distribuées en 2 repas/jour et les refus ont été collectés chaque jour. La pesée des béliers a été faite par quinzaine en 2 jours successifs. Les prix des différents ingrédients ont été suivis sur les marchés de Kollo et Niamey durant l’essai. Les GMQ obtenus étaient de 95g/j pour la formule 1 ; 79 g/j pour la formule 2 ; 59 g/j pour la formule 3 ; 118 g/j pour la formule 4 et 75g/j pour la formule 5. Les meilleures performances ont été réalisées par les béliers ayant reçu les formules 1 et 4, avec des marges nettes/ bélier de 4623 FCFA pour la formule 1 et 4763 FCFA pour la formule 4. Les formules 4, 1 et 2, ayant été les plus rentables, sont recommandées aux emboucheurs et fabricants d’aliments pour le bétail.Mots clés: Blocs multi-nutritionnels, embouche, ovins, performancesEnglish Title: Technical and economical evaluation of feeds blocks in sheep fattening in NigerEnglish AbstractA ram’s feeding trial was conducted at Kollo Regional Center for Agricultural Research, with the objective to evaluate growth performance of Ara-Ara breed rams fed 5 feed formulas based on local feedstuffs associated with cottonseed meal and wheat bran. They were 50 Ara Ara breed rams old from18 to 24 months with an average weight of 25 ± 3.02 kg. Rams were allotted into 5 treatments (feed formulas, FF1 to FF5) with ten animals/treatment. Rams were dewormed, vaccinated and kept in individual pens for 75 days. Animals were fed 2 times/day and refusals collected daily. Sheep were weighted two-weekly during 2 successive days. Ingredient prices and labor cost were collected at Kollo and Niamey during the test period, for the economic evaluation. ADG was 95 for FF1, 79 for FF2, 59 for FF3, 118 for FF4 and 75g/day for FF5. Best ADG and feed conversion were achieved by rams fed FF4 and FF1. Results showed that best net margins/ram were 4,763 FCFA for formula 4 and 4,459 FCFA for formula 1. The best rate for financial and economic profitability was for formulas 4, 1 and 2 which. Consequently, farmers and feed processors can use formulas 4, 1 and 2.Keywords: Fattening, sheep, multi-nutritional blocks, performanc

Stellar Surface Magnetoconvection as a Source of Astrophysical Noise. III. Sun-as-a-Star Simulations and Optimal Noise Diagnostics

Stellar surface magnetoconvection (granulation) creates asymmetries in the observed stellar absorption lines that can subsequently manifest themselves as spurious radial velocities shifts. In turn, this can then mask the Doppler-reflex motion induced by orbiting planets on their host stars, and represents a particular challenge for determining the masses of low-mass, long-period planets. Herein, we study this impact by creating Sun-as-a-star observations that encapsulate the granulation variability expected from 3D magnetohydrodynamic simulations. These Sun-as-a-star model observations are in good agreement with empirical observations of the Sun, but may underestimate the total variability relative to the quiet Sun due to the increased magnetic field strength in our models. We find numerous line profile characteristics linearly correlate with the disc-integrated convection-induced velocities. Removing the various correlations with the line bisector, equivalent width, and the V_asy indicator may reduce ~50-60% of the granulation noise in the measured velocities. We also find that simultaneous photometry may be a key diagnostic, as our proxy for photometric brightness also allowed us to remove ~50% of the granulation-induced radial velocity noise. These correlations and granulation-noise mitigations breakdown in the presence of low instrumental resolution and/or increased stellar rotation, as both act to smooth the observed line profile asymmetries.Comment: 18 pages + 15 pages references/appendix, 24 figures, 6 tables, accepted to Ap

Farmer preferences for groundnut traits and varieties in West Africa: Cases of Mali, Niger and Nigeria.Working Paper Series no. 27

Participatory varietal selection trials were implemented in Mali, Niger and Nigeria and were used to assess farmers’ preferences for plant and seed traits of selected groundnut varieties. Using a panel of farmers in every country, plant and seed traits were assessed and found to be statistically associated with the varieties tested. Ordered probit models were used to identify plant and seed traits liked by panelists. Color of the leaves, maturity (short cycle), number of pods, pod size, constriction, pod yield, pod filling and taste were the important attributes explaining farmers ranking for varieties in Mali. In Niger, the color of the leaves, the number of pods per plant, pod filling, pod beak, and pod yield were the most important traits sought by farmers. In Nigeria, plant vigor, plant maturity, plant type, number of pods per plant, pod size, haulm yield and pod yield were the preferred traits. These traits should be used to identify varieties (from large germplasm collections) most likely to be adopted by farmers. Varieties with traits sought by farmers should be promoted and used to build sustainable seed supply systems. Attributes such as color of leaves, pod reticulation and pod beak tend to be overlooked and should be included in future breeding programs Ndjeunga J, Ntare BR, Abdoulaye A, Ibro A, Zarafi MA, Cisse Y, Moutari A, Kodio O, Echekwu CA, Mohammed SG and Micko

Disentangling the role of Africa in the global spread of H5 highly pathogenic avian influenza

The role of Africa in the dynamics of the global spread of a zoonotic and economicallyimportant virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains unexplored. Here we characterise the spatiotemporal patterns of virus diffusion during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird migrations have contributed to the virus spreading into Africa, with West Africa acting as a crucial hotspot for virus introduction and dissemination into the continent. We demonstrate varying paths of avian influenza incursions into Africa as well as virus spread within Africa over time, which reveal that virus expansion is a complex phenomenon, shaped by an intricate interplay between avian host ecology, virus characteristics and environmental variables.USAID under the OSRO/GLO/501/USA and OSRO/GLO/507/USA projects and by European Union’s Horizon 2020 research and innovation programme under grant agreement No 727922 (DELTAFLU). The European Research Council under the European Unionʼs Horizon 2020 research and innovation programme (grant agreement no. 725422-ReservoirDOCS). P.L. acknowledges support by the Research Foundation – Flanders FWO, G066215N, G0D5117N and G0B9317N). B.V. is a postdoctoral research fellow supported by the FWO.http://www.nature.com/naturecommunicationsam2020Microbiology and Plant Patholog

Macroscopic modeling of multilane motorways using a two-dimensional second-order model of traffic flow

Lane changing is one of the most common maneuvers on motorways. Although macroscopic traffic models are well known for their suitability to describe fast moving crowded traffic, most of these models are generally developed in a one-dimensional framework; henceforth lane-changing behavior is either not explicitly modeled or is explicitly forbidden. In this paper, we propose a macroscopic model which accounts for lane-changing behavior on motorways, based on a two-dimensional extension of the Aw and Rascle [SIAM J. Appl. Math., 60 (2000), pp. 916-938] and Zhang [Transport. Res. B-Meth., 36 (2002), pp. 275-290] macroscopic model for traffic flow. Under conditions when lane-changing maneuvers are no longer possible, the model "relaxes"to the onedimensional Aw-Rascle-Zhang model. Following the same approach as in [SIAM J. Appl. Math., 63 (2002), pp. 259-278], we derive the two-dimensional macroscopic model through scaling of time discretization of a microscopic follow-the-leader model with driving direction. We provide a detailed analysis of the space-time discretization of the proposed macroscopic model as well as an approximation of the solution to the associated Riemann problem. Furthermore, we illustrate some promising features of the proposed model through some numerical experiments