Ingestion alimentaire de caprins sur pâturages de hautes montagnes dans le Nord du Maroc

This study was carried out in three mountainous sites that are located within the region of Chefchaouen, namely Bouhalla, Chrafat and Kalaâ. The study sets out to shed light on local goats that graze along high-mountain pastures. Its objective was to determine the feed share these animals get from those pastures, with due regard to both the site and the period (cold/hot). Across the entire site, the average quantity of dry mater (DM) ingested was 1.35 Kg (i.e. 0.50 FU). According to the site, the values were 1.80; 1.17 and 1.06 Kg in Chrafat, Kalaâ and Bouhalla, respectively. This quantity also varied in accordance with the period: 1.58 Kg in the cold period; and 1.11Kg in hot weather. It also differed according to the category and the age of the animal (respectively: from 0.97 to 1.10 and from to 1.40/1.85 Kg, in young nanny goats and baby goats, on the one hand; and nanny goat and billy goat, on the other hand). Unfortunately, these rates do not last long. These results will ultimately contribute to the development of adequate feed shares for goat ranches in high mountains according to their specificities.L’étude a été effectuée dans trois sites montagneux (Bouhalla, Chrafat et Kalaâ) de la région de Chefchaouen. Elle a concerné une population caprine locale conduite sur pacages de hautes montagnes. Son principal objectif était de déterminer les prélèvements alimentaires en fonction du site et de la période (froide/chaude). La quantité moyenne de matière sèche (MS) prélevée quotidiennement par le caprin, a été de 1,35 Kg (soit 0,50 UF). Elle a été de 1,80 ; 1,17 et 1,06 Kg à Chrafat, Kalaâ et Bouhalla, respectivement. Cette quantité a varié aussi selon la période : 1,58 Kg MS en période froide ; et 1,11 MS en période chaude. Elle différait également en fonction de la catégorie et de la classe d'âge (respectivement : de 0,97 à 1,10 et de 1,40 à 1,85 Kg, chez les chevrettes et chevreaux, d'une part ; et les chèvres et boucs, d'autre part). Ces résultats contribueront, à terme, à l'élaboration de rations alimentaires adéquates pour des élevages caprins de hautes montagnes en fonction de leurs spécificités

Variability in Responses to Phoma medicaginis Infection in a Tunisian Collection of Three Annual Medicago Species

Spring black stem and leaf spot, caused by Phoma medicaginis, is an issue in annual Medicago species. Therefore, in this study, we analyzed the response to P. medicaginis infection in a collection of 46 lines of three annual Medicago species (M. truncatula, M. ciliaris, and M. polymorpha) showing different geographic distribution in Tunisia. The reaction in the host to the disease is explained by the effects based on plant species, lines nested within species, treatment, the interaction of species × treatment, and the interaction of lines nested within species × treatment. Medicago ciliaris was the least affected for aerial growth under infection. Furthermore, the largest variation within species was found for M. truncatula under both conditions. Principal component analysis and hierarchical classification showed that M. ciliaris lines formed a separate group under control treatment and P. medicaginis infection and they are the most vigorous in growth. These results indicate that M. ciliaris is the least susceptible in response to P. medicaginis infection among the three Medicago species investigated here, which can be used as a good candidate in crop rotation to reduce disease pressure in the field and as a source of P. medicaginis resistance for the improvement of forage legumes

Composition chimique, digestibilité et valeur fourragère des plantes fourragères pastorales pérennes de hautes montagnes de la région Nord du Maroc

Forest pastures represent the basis of livestock feed in the high mountains of the north region of Morocco. Unfortunately, the forage supply of pastoral species is subject to a continuous decrease, which exposes the livestock to under nutrition. In order to manage this situation and to improve the herd nutrition, knowledge of the energy and protein content and the digestibility of consumed plant species is essential. The analyses of 22 main pastoral forage species showed that the energy and protein values of these species are moderately low for UF (0.28 to 0.52 UFV/kg DM) and very low for PDI (16 to 52 g/kg/MS). The most abundant species consumed by goats, namely Quercus ilex, Quercus canariensis, Quercus suber and Pistacia lentiscus, present low energy (0.33 UF/kg DM) and low protein forage (28 g PDI/kg DM) foods. In general, these species are characterized by a satisfactory digestibility. This varies from 53% to 90% for the organic matter digestibility (DMO %). Some species have a lower DMO (52% to 66%). This is the case of Ceratonia siliqua, Cytisus scoparius, Olea europaea, Quercus Suber, Quercus ilex, Arbutus unedo, Rubus ulmifolius, Tetraclinis articulata. Similarly, a low protein digestibility is noted in Phillyrea media, Arbutus unedo and Pistacia lentiscus (64%, 65% and 66% respectively). On this basis, it appears that the pastures in these areas are also degraded in terms of nutrition.Les pâturages forestiers représentent la base de l’alimentation du cheptel animal en hautes montagnes dans le Nord du Maroc. Malheureusement, l’offre fourragère des espèces pastorales est sujette à une diminution continue, ce qui expose le cheptel à une sous nutrition. Pour pouvoir gérer cette situation et améliorer l’alimentation des troupeaux, la connaissance de l’apport énergétique et protéique et de la digestibilité des espèces de plantes consommées est indispensable. Les analyses menées sur 22 principales espèces fourragères pastorales, ont montré que la valeur énergétique et protéique de ces espèces est moyennement faible pour les UF (0,28 à 0,52 UFV/kg MS) et très faible pour les protéines (16 à 52 g de PDI/kg/MS). Les espèces les plus abondantes et les plus consommées par les caprins, à savoir Quercus ilex, Quercus canariensis, Quercus suber et Pistacia lentiscus, représentent les aliments les moins énergétiques (0,33 UF/kg MS) et les moins protéiques (28 g PDI/kg MS). De manière générale, ces espèces se caractérisent par une digestibilité satisfaisante qui varie de 53% à 90% pour la digestibilité de la matière organique (DMO%). Certaines espèces présentent une DMO moins élevée (52% à 66%). C’est le cas de Ceratonia siliqua, Cytisus scoparius, Olea europaea, Quercus Suber, Quercus ilex, Arbutus unedo, Rubus ulmifolius, Tetraclinis articulata. De même, on note une faible digestibilité des protéines chez Phillyrea media, Arbutus unedo et Pistacia lentiscus (64%, 65% et 66% respectivement). Sur cette base, Il apparait que les pâturages au niveau de ces zones sont aussi dégradés sur le plan nutritif

Variability in Responses to Phoma medicaginis Infection in a Tunisian Collection of Three Annual Medicago Species

Spring black stem and leaf spot, caused by Phoma medicaginis, is an issue in annual Medicago species. Therefore, in this study, we analyzed the response to P. medicaginis infection in a collection of 46 lines of three annual Medicago species (M. truncatula, M. ciliaris, and M. polymorpha) showing different geographic distribution in Tunisia. The reaction in the host to the disease is explained by the effects based on plant species, lines nested within species, treatment, the interaction of species × treatment, and the interaction of lines nested within species × treatment. Medicago ciliaris was the least affected for aerial growth under infection. Furthermore, the largest variation within species was found for M. truncatula under both conditions. Principal component analysis and hierarchical classification showed that M. ciliaris lines formed a separate group under control treatment and P. medicaginis infection and they are the most vigorous in growth. These results indicate that M. ciliaris is the least susceptible in response to P. medicaginis infection among the three Medicago species investigated here, which can be used as a good candidate in crop rotation to reduce disease pressure in the field and as a source of P. medicaginis resistance for the improvement of forage legumes

Ingestion alimentaire de caprins sur pâturages de hautes montagnes dans le Nord du Maroc

This study was carried out in three mountainous sites that are located within the region of Chefchaouen, namely Bouhalla, Chrafat and Kalaâ. The study sets out to shed light on local goats that graze along high-mountain pastures. Its objective was to determine the feed share these animals get from those pastures, with due regard to both the site and the period (cold/hot). Across the entire site, the average quantity of dry mater (DM) ingested was 1.35 Kg (i.e. 0.50 FU). According to the site, the values were 1.80; 1.17 and 1.06 Kg in Chrafat, Kalaâ and Bouhalla, respectively. This quantity also varied in accordance with the period: 1.58 Kg in the cold period; and 1.11Kg in hot weather. It also differed according to the category and the age of the animal (respectively: from 0.97 to 1.10 and from to 1.40/1.85 Kg, in young nanny goats and baby goats, on the one hand; and nanny goat and billy goat, on the other hand). Unfortunately, these rates do not last long. These results will ultimately contribute to the development of adequate feed shares for goat ranches in high mountains according to their specificities.L’étude a été effectuée dans trois sites montagneux (Bouhalla, Chrafat et Kalaâ) de la région de Chefchaouen. Elle a concerné une population caprine locale conduite sur pacages de hautes montagnes. Son principal objectif était de déterminer les prélèvements alimentaires en fonction du site et de la période (froide/chaude). La quantité moyenne de matière sèche (MS) prélevée quotidiennement par le caprin, a été de 1,35 Kg (soit 0,50 UF). Elle a été de 1,80 ; 1,17 et 1,06 Kg à Chrafat, Kalaâ et Bouhalla, respectivement. Cette quantité a varié aussi selon la période : 1,58 Kg MS en période froide ; et 1,11 MS en période chaude. Elle différait également en fonction de la catégorie et de la classe d'âge (respectivement : de 0,97 à 1,10 et de 1,40 à 1,85 Kg, chez les chevrettes et chevreaux, d'une part ; et les chèvres et boucs, d'autre part). Ces résultats contribueront, à terme, à l'élaboration de rations alimentaires adéquates pour des élevages caprins de hautes montagnes en fonction de leurs spécificités

Trophic condition of seven mediterranean freshwater reservoirs : Environmental factors and zooplanktonic community

International audienc

Phytoplankton : Ecology, Aquaculture and Blooms

International audienc

Seasonal dynamics of zooplankton community in four Mediterranean reservoirs in humid area (Beni Mtir: north of Tunisia) and semi arid area (Lakhmes, Nabhana and Sidi Saâd: center of Tunisia)

International audienceThe zooplankton community was studied in four Mediterranean reservoirs to assess the relative importance of environmental factors as determinants of zooplankton dynamic in the four seasons. The water temperature and hydrology variations affect the distribution of zooplankton. A positive correlation was established between the total zooplankton and the water temperature (r=0.9, n=9, p<0.05). Fourteen zooplankton species were identified. Seasonal changes in the density (ANOVA, F=3.7, d.f=36, p<0.01) and the biomass of total zooplankton (ANOVA, F=4.4, d.f=36, p<0.001) were observed. Our results suggest that planktivorous fish may not modify the zooplankton dynamics in Beni Mtir reservoir (oligotrophic). On the contrary, in Sidi Saâd reservoir (mesotrophic), fish predation has major effects on seasonal zooplankton dynamics

Improving the mechanical performances of a multilayered plate with the orientations of its layers of fibers

International audienceWe consider a symmetric composite multilayered plate whose fiber orientation variesfrom a layer to another. The plate model used is that of Mindlin. We are interested indetermining the optimal fiber orientations that optimize, in the same time, two criteria:minimizing the compliance and maximizing the smallest eigenfrequency of vibration orminimizing both of the compliance and the smallest eigenfrequency or maximizing bothof the smallest eigenfrequency and the smallest buckling load. In order to optimize one ofthe above criteria, a metaheuristic algorithm of Simulated Annealing type is used. While, inthe case of optimizing two objectives, the Pareto front method is used. Numerical resultsare presented for a rectangular eight-layered plate