Influence de quelques paramètres intrinsèques liés à l’animal sur la fréquence des mammites subcliniques des vaches laitières

The aim of this study is to determine the risk factors for subclinical mastitis, and the effect of the breed, number and stage of lactation of cows on their frequency in dairy cattle farms in the Constantine region. The study involved 20 small and medium herds of dairy cattle from the Constantine region in eastern Algeria. A survey was conducted for the collection of data concerning: the number of cows, the exploited breeds end the type of breeding. The California Mastitis Test (CMT) was carried out for the detection of subclinical mastitis. The results of the survey show that Prim'Holstein is the most exploited breed by dairy farmers. The number of dairy cows exploited ranges from 3 to 80 cows. Animal housing consists of concrete floor in 95% of farms. The results of CMT show that the race most affected by subclinical mastitis is Montbeliarde, thus, the incidence of mastitis is higher in the first and third thirds of lactation, however, the incidence of mastitis has been little modified by the lactation number of the cows. Key words: Dairy cows, Subclinical mstitis, Survey, CMT, ConstantineL’objectif de cette étude consiste à déterminer les facteurs de risque des mammites subcliniques ainsi que l’effet de la race, du numéro et du stade de lactation des vaches sur leur fréquence dans les élevages de bovins laitiers de la région de Constantine. L’étude a concerné 20 petits et moyens troupeaux de bovins laitiers de la région de Constantine à l’Est algérien. Une enquête a été réalisée pour la collecte des données concernant le nombre de vaches, les races exploitées et le type d’élevage. Le California Mastitis Test (CMT) a été réalisé pour la détection des mammites subcliniques. Les résultats de l’enquête montrent que la Prim’Holstein est la race la plus exploitée par les producteurs laitiers. Le nombre de vaches laitières exploitées varie de 3 à 80 vaches. Le logement des animaux est constitué d’un sol bétonné dans 95% des exploitations. Les résultats du CMT montrent que la race la plus affectée par les mammites subcliniques est la Montbéliarde, ainsi, la fréquence des mammites est plus élevée au 1er tiers et au dernier tiers de lactation, cependant, la fréquence des mammites a été peu modifiée par le numéro de lactation des vaches. Mots clés : bovins laitiers, mammites subcliniques, enquête, CMT, Constantin

Reply to the comment by A. G. Jones et al. on “Deep resistivity cross section of the intraplate Atlas Mountains (NW Africa): new evidence of anomalous mantle and related Quaternary volcanism"

Scientific discussion and different points of view are a basis of the advancement of knowledge. We acknowledge the comments of Jones et al. [2012] as an opportunity to publicly discuss the structure and origin of the Atlas Mountains. Moreover, we welcome the opportunity to compare our results with those recently published by the group responsible for the comment [Ledo et al., 2011], although it is not pertinent to comment in detail on a paper published in another journal. We also wish to remark that the paper of Ledo et al. [2011] was reviewed and published during the revision period of our contribution [Anahnah et al., 2011]; therefore, they are two different approaches and data sets, measured in different sites and by different instruments for the same region, lending readers the chance to compare different interpretations. The main differences on the data sets are: the profile of Anahnah et al. [2011] compared with the profile of Ledo et al. [2011] is 170 km longer, vertical magnetic data were obtained and lower frequencies were recordedDepartamento de Geodinámica, Universidad de Granada, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaDépartement de Géologie, Université Mohammed V, MarruecosUnidad de Granada, Instituto Geológico y Minero de España, EspañaDepartament de Geodinàmica i Geofísica, Universitat de Barcelona, EspañaInstitute of Geological & Nuclear Sciences Limited, Nueva ZelandaGéosciences Montpellier, Université Montpellier, FranciaDépartement de Géologie, Université Abdelmalek Esaadi, MarruecosCentro de Geociencias, Universidad Nacional Autónoma de México, Méxic

Synthesis, Characterization, and Crystal Structure Determination of a New Lithium Zinc Iodate Polymorph LiZn(IO3)3

International audienc

Crustal resistivity structure of the southwestern transect of the Rif Cordillera (Morocco)

International audienceA NE-SW magnetotelluric 110 km-long profile including 18 sites was acquired across the western Rif Cordillera along the Eurasian-African plate boundary, allowing to constrain its poorly known deep structure. It extends from the Internal Zones, close to the Alboran coast, crossing the External Zones and up to the Gharb foreland basin. The periods recorded range from 0.001 s to 1000 s. The combination of magnetotelluric data with available geological data provides new insight regarding the relationship between deep and shallow crustal structures of the Rif Cordillera. Analyses of structural dimensionality suggest a preferential NW-SE direction, and a 2D joint inversion was performed. A 3D inversion extending the 2D model along the strike confirmed the reliability of this approach. The magnetotelluric model shows a heterogeneous upper crust in agreement with the geological structures observed at surface. The Internal Zones correspond to resistive (metamorphic rocks) and conductive (peridotites) bodies, while the External Zones and the foreland basin are characterized by large conductive bodies of variable thickness. A crustal detachment level separating shallow geological units from a probable variscan basement was inferred. At depth, the most relevant feature consists of large resistive bodies with a shallow irregular top, located below the frontal part of the Rif. The outcrops of exotic metapelitic, granitic and gneissic blocks in the frontal part of the Cordillera suggest that these large resistive bodies may correspond to a gneissic or granitic basement surrounded by metapelitic rocks. Late contractive thrust and diapiric processes were responsible for their uplift and shallow emplacement. The Rif constitutes an active southwestward vergent orogenic wedge, oblique to the present-day NW-SE convergent Eurasian-African plate boundary

Deep resistivity cross section of the intraplate Atlas Mountains (NW Africa): New evidence of anomalous mantle and related Quaternary volcanism

International audienceThe Atlas Mountains are characterized by high elevations and Quaternary volcanism. Long period magnetotelluric data acquired along a NNW-SSE transect reveal the presence of a conductive anomalous mantle below the High Atlas. Data dimensionality analyses show a preferent N80 degrees E strike of the deep resistivity structure in agreement with the induction vector alignment at long periods. Accordingly, a 2D inversion of the data set was carried out. Large resistive bodies at the crustal basement most likely correspond to batholiths emplaced in more conductive metapelites. They are covered by outcropping conductive sedimentary detritic and carbonate rocks. Lithospheric thinning producing anomalous mantle and basin development in the Atlas probably started during Triassic-Jurassic rifting. Inversion tectonics since the Oligocene produced low shortening on previous lithospheric weak zones, with thrusting of the Atlas above the stable African plate. Melting at the top of the anomalous mantle is connected with Quaternary basaltic volcanism in the Middle Atlas

Active structures and geological hazards in the central sector of the Betic-Rif Cordillera and the Alboran Sea

X Congreso Geológico de España, 5-7 de julio 2021, Vitoria-Gasteiz.-- 1 page[EN] The recent geodynamic activity in the Betic-Rif Cordillera and the Alboran Sea is determined by the interaction of subduction processes with roll-back in the West and tectonic indentation in the East. The integration of sea and land data in the DAMAGE project characterizes the central area of interaction. At the northern end, the seismicity of the frontal region of Sierra de Cazorla is associated with incipient tectonic indentation. To the South, seismic and aseismic extensional faults of high and low angle interact in the Granada Basin. The active normal faults in the Campo de Dalías are connected with recent and new strike-slip faults that affect the Alboran Sea, being responsible of the 2016 Alhoceima earthquake (M 6.3). Towards the Rif, new areas of deformation in the Al Hoceima region are identified on blind faults with significant seismogenic activity in 1993 and 2004. These structures represent an important geological hazard related to slope instability and tsunami development in the Alboran Sea and in water reservoirs. The economic and social impact of this geological hazard should be considered and quantified[ES] La actividad geodinámica reciente en la Cordillera Bético-Rifeña y el Mar de Alborán está determinada por la interacción entre los procesos de subducción con roll-back en el Oeste y la indentación tectónica en el Este. La integración de datos en mar y tierra en el proyecto DAMAGE caracteriza la zona central de interacción. En el extremo septentrional, la sismicidad de la región frontal de Sierra de Cazorla está asociada a indentación tectónica incipiente. Hacia el Sur, en la Cuenca de Granada, interaccionan fallas extensionales sísmicas y asísmicas de alto y bajo buzamiento. Las fallas normales activas en el Campo de Dalías, están conectadas con fallas de salto en dirección neoformadas que afectan el Mar de Alborán, y son responsables del terremoto de Alhucemas de 2016 (M 6.3). Hacia el Rif se identifican nuevas zonas de deformación en Alhucemas sobre fallas ciegas con importante actividad sismogénica en 1993 y 2004. Estas estructuras tienen asociada una importante peligrosidad geológica relacionada con la estabilidad de los taludes y la generación de tsunamis en el Mar de Alborán y estabilidad de masas de agua en embalses, cuya incidencia económica y social se debe considerar y cuantificarPeer reviewe