Etude de l’impact de l’adjonction du monensin dans l’alimentation sur les performances de production des agneaux et des chevreaux élevés en ateliers d’engraissement

The objective of this trial was to study the effect of monensin on lambs and kids fattening performances. It was conducted in Sidi Bettach, using 72 lambs and 24 kids, weighing 17 and 21 kg respectively. Experimental concentrate feed included monensin at 15 ppm. At the end of the field trial which lasted 72 days, 26 lambs were slaughtered in Casablanca for carcass characteristics assessment. Incorporation of monensin in the feed did not improve lambs and kids production performances, namely feed intake, average daily gain (ADG) and feed efficiency. Nevertheless, a significant improvement was observed for lambs, during the second period of the experiment for the dietary intake (+2 %) and during the first one for the ADG (+33 g). Furthermore, monensin did not have any effect on carcass characteristics since we even obtained a higher dressing percentage in control group compared to the treated one. In light of the obtained results, it appears overall that under our experimental conditions, monensin incorporation in fattening small ruminants feed did not have any significant effect on their performances

First molecular evidence of potential Culicoides vectors implicated in bluetongue virus transmission in Morocco

Abstract Background Bluetongue is a non-contagious viral disease that affects both domestic and wild ruminants. It is transmitted primarily by small hematophagous Diptera belonging to the genus Culicoides (Diptera: Ceratopogonidae). The current study represents the first molecular investigation into the potential role of Culicoides imicola, Culicoides paolae, Culicoides newsteadi, Culicoides spp., and Culicoides circumscriptus as bluetongue virus (BTV) vectors in Morocco. Additionally, the study aimed to evaluate the vectorial activity of midges during the survey seasons. Methods Parous females of these species were captured from several regions of Morocco (6 out of 12) from 2018 to 2021 using Onderstepoort Veterinary Institute (OVI) traps. A total of 2003 parous female specimens were grouped into 55 batches. The midge body of each batch was dissected into three regions (head, thorax, and abdomen), and these regions were analyzed separately using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Results BTV RNA was detected in 45 out of the 55 batches tested, indicating a positivity rate of 81.8%. The RT-qPCR-positive pools of the studied Culicoides species exhibited high levels of BTV positivity in each body part (head, thorax, and abdomen), confirming the successful replication of the virus within midge bodies. The BTV circulation was substantial across all three survey seasons (spring, summer, and autumn). High infection rates, calculated using the minimum infection rate (MIR) and maximum likelihood estimation (MLE), were observed during the collection seasons, particularly in autumn and spring, and for all investigated Culicoides species, most notably for C. imicola and C. newsteadi. These increased infection rates underscore the significant risk of Culicoides transmitting the BTV in Morocco. Conclusions The detection of BTV positivity in Culicoides spp. (lacking wing spots that allow their differentiation according to morphological identification keys) suggested that other Culicoides species are competent for BTV transmission in Morocco. The study results indicated, for the first time at the molecular level, that C. imicola and C. newsteadi are the primary potential vectors of BTV in Morocco and that C. paolae and C. circumscriptus are strongly implicated in the propagation of bluetongue at the national level. Graphical Abstrac

Etude de l'impact de l'adjonction du monensin dans l'alimentation sur les performances de production des agneaux et des chevreaux élevés en ateliers d'engraissement

The objective of this trial was to study the effect of monensin on lambs and kids fattening performances. It was conducted in Sidi Bettach, using 72 lambs and 24 kids, weighing 17 and 21 kg respectively. Experimental concentrate feed included monensin at 15 ppm. At the end of the field trial which lasted 72 days, 26 lambs were slaughtered in Casablanca for carcass characteristics assessment. Incorporation of monensin in the feed did not improve lambs and kids production performances, namely feed intake, average daily gain (ADG) and feed efficiency. Nevertheless, a significant improvement was observed for lambs, during the second period of the experiment for the dietary intake (+2 %) and during the first one for the ADG (+33 g). Furthermore, monensin did not have any effect on carcass characteristics since we even obtained a higher dressing percentage in control group compared to the treated one. In light of the obtained results, it appears overall that under our experimental conditions, monensin incorporation in fattening small ruminants feed did not have any significant effect on their performances.  Keywords: Monensin, Production performance, Lambs, Kids, Feedlot, Sidi Bettach, MoroccoL’objectif de cet essai est d’étudier l’effet de l’incorporation du monensin dans la ration d’agneaux et de chevreaux sur leurs performances d’engraissement. Il a été réalisé à Sidi Bettach, moyennant 72 agneaux et 24 chevreaux, ayant des poids vifs moyens initiaux respectifs de 17 et de 21 Kg. L’aliment concentré expérimental contient du monensin à une dose de 15 mg/kg de matière sèche (15 ppm). L’essai a duré 72 jours. A l’issue de cet essai, 26 agneaux ont été abattus aux abattoirs de Casablanca pour apprécier les caractéristiques de leurs carcasses. L’incorporation du monensin n’a permis aucune amélioration des performances de production à l’engraissement, à savoir l’ingestion alimentaire, le gain moyen quotidien (GMQ) et l’efficacité alimentaire. Néanmoins, une amélioration significative a été observée chez les agneaux, pendant la 2ème période de l’essai, pour l’ingestion alimentaire (+2 %) et pendant la 1ere période pour le GMQ (+ 33 g). Pour ce qui est des caractéristiques des carcasses, l’adjonction du monensin s’est avérée également sans effet, du fait que leur rendement et les poids de frisures obtenus chez les animaux témoins ont été supérieurs par rapport à ceux traités. Il ressort de la présente étude que, sous nos conditions expérimentales, l’utilisation du monensin comme promoteur de croissance n’a pas été d’une efficacité notable chez les petits ruminants à l’engraissement. Mots clés: Monensin, Performances de production, Engraissement, Agneaux, Chevreaux, Sidi Bettach, Maroc &nbsp

Development of Mice Model for the West Nile Virus (Strain Mor/1996)

La présente étude a pour objectif l’élaboration et la validation d’un modèle souris pour l’infection in vivo du virus de la West Nile (WNV). Pour ce faire, 90 souris albinos natives non vaccinées ont été réparties en trois lots selon trois modes d’inoculation, à savoir: Intracérébral (IC), Sous-cutanée (SC) et Intrapéritonéale (IP). Chaque lot a été composé de 25 animaux chalengés et cinq témoins. Après inoculation, des observations quotidiennes de symptômes cliniques ont été réalisées selon un tableau de scoring préétabli sur une période de 2 mois. Après la mort des animaux, une autopsie et une décérébration ont été réalisées, en vue d’une analyse histo-pathologique, et un test RT-PCR. Les résultats ont montré que le tableau clinique le plus complet était observé chez les animaux inoculés par voie IP et SC, à savoir: ataxie, amaigrissement, une déshydratation, signes de constipation, une fasciculation et une cécité. Cependant, pour la voie IC, la majorité des souris sont mortes d’une mort foudroyante sans manifester de signes cliniques en dehors de l’ataxie. Le taux de mortalité parmi les animaux inoculés était de 96% pour la voie IC, 56% pour la voie IP et 44% pour la voie SC. L’examen histo-pathologique a montré des signes non pathognomoniques mais bien marqués comme: une gliose discrète à modérée, focale périvasculaire et une dégénérescence et nécrose neuronale discrète à modérée. En revanche, tous les échantillons testés par RT-PCR ont été positifs au WNV. Par ailleurs, le calcul de la DL50 a révélé des valeurs de 104,3 et de 104,8 respectivement pour les IC et IP. Il ressort de la présente étude que les voie d'inoculation validées pour le modèle souris de l’infection avec le virus du Nil occidental (WNV), sont les voie IP et SC. Mots-clés:  West Nile, Modèle-souris, Challenge, RT-PCRThe present study aims to develop and validate a mouse model for in vivo infection with West Nile Virus (WNV). To achieve this, 90 non-vaccinated native albino mice were divided into three groups according to three modes of inoculation: Intracerebral (IC), Subcutaneous (SC), and Intraperitoneal (IP). Each group consisted of 25 challenged animals and five controls. After inoculation, daily observation of clinical symptoms was conducted based on a predetermined scoring chart over a period of 2 months. After the animals' deaths, autopsy and decerebration were performed for histopathological analysis and an RT-PCR test. The results showed that the most comprehensive clinical presentation was observed in animals inoculated via the IP and SC routes, including ataxia, weight loss, dehydration, signs of constipation, fasciculation and blindness. However, for the IC route, the vast majority of mice suddenly died without exhibiting clinical signs, apart from ataxia. The mortality rate among inoculated animals was 96% for the IC route, 56% for the IP route and 44% for the SC route. Histopathological examination revealed non-pathognomonic but well-marked signs such as discrete to moderate focal perivascular gliosis and mild to moderate neuronal degeneration and necrosis. On the other hand, all samples tested by RT-PCR were positive for WNV. Furthermore, the calculation of the LD50 revealed values of 104.3 and 104.8 for IC and IP routes respectively. It results from this study that the validated inoculation routes for the mouse model of West Nile virus infection are the IP and SC routes. Keywords:  West Nile, Mice- Model, Challenge, RT-PC

Serological and Molecular Characterization of Small Ruminant Lentiviruses in Morocco

Recent studies that investigated the origins of SRLV strains offered new insights into their distribution among domestic ruminants. The aim of the study was to investigate SRLV circulation in Morocco. A total of 51 farms were selected in different geographical locations and tested by screening and genotyping ELISA. Whole blood was used for DNA extraction and nested gag PCR. The sample size allowed for an estimation of prevalence lower than 20% (CI 95%). Surprisingly, a large proportion of screening-positive samples were not correctly serotyped. Sanger and NGS amplicon sequencing approaches allowed us to obtain new sequences even from difficult-to-amplify samples. The serological data support the evidence of an intrinsic difficulty of SRLV to spread, likely due to management practices. The low rate of success by genotyping ELISA led us to suppose that divergent strains might have escaped from diagnostic tools, as partially confirmed by the evidence of an A subtype carrying a mismatch in serotyping epitope. The sequence analysis revealed the circulation of novel B and recombinant A/B subtypes. This study highlights the importance of monitoring viral sequences and their evolution to develop specific diagnostic tests, particularly in countries where control measures are in place

Additional file 1: of Knowledge, attitudes and practices with regard to the presence, transmission, impact, and control of cystic echinococcosis in Sidi Kacem Province, Morocco

Multilingual abstracts in the six official working languages of the United Nations. (PDF 552 kb