HAL ENVT (Ecole Nationale Vétérinaire de Toulouse)
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Évaluation des connaissances en alimentation féline des personnes présentes dans les expositions félines
No full textThis study aimed to assess the knowledge of visitors to feline exhibitions in France regarding cat nutrition. Two prior investigations—conducted in Switzerland and France, respectively—had demonstrated that attendees of canine exhibitions, regardless of their professional status, generally lacked understanding of the fundamental principles of dog nutrition. The objective of this thesis was to conduct a comparable survey focused on feline nutrition. The findings indicate that cat owners exhibit limited knowledge of basic nutritional principles for cats. For several questions where the rate of correct responses exceeded 50%, the difference in performance between professionals and non-professionals was not statistically significant in most cases (6 out of 9 questions). These results underscore the need to enhance nutritional education, including for professionals within the field.Notre travail a consisté à réaliser une enquête sur les connaissances des visiteurs d’expositions félines en alimentation du chat. Deux études préalables, une menée en Suisse puis une en France, avaient montré que les visiteurs des expositions canines ne connaissaient pas les principes de base en l’alimentation canine, que ce soit des professionnels ou non. L’objectif de cette thèse est de réaliser ce même type d’enquête pour le chat, en France. Les résultats montrent que les utilisateurs de chat connaissent mal les principes de base en alimentation. Pour certaines questions, quand le taux de bonne réponse était supérieur à 50%, la différence entre les professionnels et non professionnels n’a pas été, dans la majorité des cas (6 questions sur 9) significative. Cette constatation montre qu’il est nécessaire de développer les formations en alimentation, même pour les professionnels
Bisphenol analogue exposure at low concentrations modifies heart-brain functions and transcriptomics in zebrafish larvae
No full textInternational audienceSubstituting bisphenol A (BPA) with analogues could mitigate environmental harm. By mimicking water contamination and using zebrafish larvae, we tested the hypothesis that low environmentally relevant concentrations of BPS, BPF, and BPAF, compared to BPA, elicit physiological and molecular modifications. We verified lethal doses (LD₅₀; BPAF > BPF > BPA > BPS) using an OECD-compliant protocol and reported the absence of morphological and muscle abnormalities, and hatching delays below the LD₅₀ at 5 days post-fertilization (dpf). We identified the lowest bisphenol exposure levels that provoke the most significant motor-swimming changes (100 ng/L BPS, 10 ng/L BPF, 100 ng/L BPAF, and 100 ng/L BPA). We asked whether the observed motor phenotype at low bisphenol levels could be underpinned by heart-brain electrophysiological adaptations. Using in vivo optical mapping, we found increased high-frequency, low-amplitude brain activity and, in the cases of BPF and BPAF, bradycardia. Within these specific low-exposure settings, transcriptomics identified eight genes involved in heart-brain functions, homeostatic and immune regulation, that were down-regulated by each bisphenol, namely anxa1c, vwa10.1, zgc:172053, grna.2, ehf, gna14, ca15c, atp1a1a.5. Low environmentally relevant concentrations of bisphenol analogues modify organ physiology and the transcriptome in zebrafish larvae. The implications for ecotoxicology and the one-health framework are discussed
“These measures make no sense for our farming system”: Biosecurity Challenges and Adaptations in french small-scale poultry farms selling directly to consumers
No full textInternational audienceOver the past decade, outbreaks of Highly Pathogenic Avian Influenza (HPAI) have significantly impacted the global poultry industry, resulting in the implementation of biosecurity regulations. Small-scale poultry farmers selling directly to consumers have faced difficulties in implementing these measures due to the specific features of their farms. We examined the social, technical and regulatory rules which drive the production of small-scale poultry farms selling directly to consumers, and then analyzed the barriers and opportunities for implementing biosecurity measures. This study analyzed qualitative data from 36 semistructured interviews conducted in two French poultry production areas between January and October 2023. The interviews were recorded and transcribed, then thematically analyzed to identify recurring themes. Our results show that small-scale poultry farmers share strong values rooted in their autonomy over decisionmaking and traditional farming practices that are based on free-range livestock farming, high-value products, and local know-how. Despite widely diverse settings, farmers in this production sector demonstrate a strong sense of professional identity. Our results also show that recurrent HPAI epidemics and associated regulations have disrupted small-scale farming systems. Verbatims revealed tensions between biosecurity guidelines and several aspects of small-scale production, including farming practices (such as visitors’ access to farms), values (free-range farming), workload, and financial sustainability. To move beyond these biosecurity tensions, some initiatives have been developed, such as personalized training and advice for small-scale farmers. However, these solutions only reach a small proportion of producers. This suggest that biosecurity compliance on small-scale farms cannot be achieved without simultaneously addressing social, technical, and regulatory issues
Identification et gestion des strongyloses digestives chez les veaux, étude de cas sur des veaux élevés en allaitement artificiel en nouvelle zélande
No full textDigestive strongylosis in calves is a major problem in New Zealand's intensive pastoral farming systems. The emergence of anthelmintic resistance is leading to disastrous treatment impasses on some New Zealand farms. Thus, it is necessary to be informed about the parasite load at the farm level in order to adapt the treatments administered to the animals. The Homelands project is a case study conducted on a New Zealand artificial calf rearing farm. This project aims to determine the parasite load on young calves in the farm, identify the parasite species present and assess the potential for anthelmintic resistance. To answer this question, fecal samples were collected in May (autumn) and August (winter) 2024. Coproculture showed a low overall parasite load (<100 OPG). The main parasite genera identified by coproculture were Ostertagia ostertagi, Cooperia oncophora and Trichostrongylus axei. The resistance potential could not be assessed by FECRT due to low initial infestation rates. The results of this study show that Homelands Farming Ltd is currently free from major parasite problems.Les strongyloses digestives chez les veaux sont un problème majeur dans les systèmes d'élevage pastoraux néo-zélandais. L’émergence de phénomènes de résistance aux anthelminthiques entraîne des impasses thérapeutiques désastreuses dans certaines fermes néo-zélandaises. Ainsi, il est nécessaire d’être informé sur la charge parasitaire à l’échelle d’une ferme afin d’adapter les traitements administrés aux animaux. Le projet Homelands est une étude de cas réalisée dans une ferme néo-zélandaise d’allaitement artificiel de veaux. Ce projet vise à déterminer la charge parasitaire sur les jeunes veaux de la ferme, identifier les espèces parasitaires présentes et évaluer le potentiel de résistances aux anthelminthiques. Pour cela, des prélèvements de fèces ont été réalisés en mai (automne) et août (hiver) 2024. La coproscopie a montré une faible excrétion parasitaire globale (<100 OPG). Les genres de parasites principaux identifiés par coproculture sont Ostertagia spp., Cooperia spp. et Trichostrongylus spp. Le potentiel de résistance par FECRT n’a pas pu être évalué dû à de trop faibles taux d’excrétion d'œufs initiaux. Le bilan de cette étude montre que Homelands Farming Ltd est pour le moment à l'abri de problème
The receptor-like cytoplasmic kinase AeRLCK2 mediates Nod-independent rhizobial symbiosis in Aeschynomene legumes
No full textInternational audienceMany plants interact symbiotically with arbuscular mycorrhizal fungi to enhance inorganic phosphorus uptake, and legumes also develop a nodule symbiosis with rhizobia for nitrogen acquisition. The establishment and functioning of both symbioses rely on a common plant signaling pathway activated by structurally related Myc and Nod factors. Recently, a SPARK receptor-like kinase (RLK)/receptor-like cytoplasmic kinase (RLCK) complex was shown to be essential for arbuscular mycorrhiza formation in both monocot and dicot plants. Here, we show that in Aeschynomene legumes, the RLCK component of this receptor complex has undergone a gene duplication event and mediates a unique nodule symbiosis that is independent of rhizobial Nod factors. In Aeschynomene evenia, AeRLCK2 is crucial for nodule initiation but not for arbuscular mycorrhiza symbiosis. Additionally, AeRLCK2 physically interacts with and is phosphorylated by the cysteine-rich RLK, AeCRK, which is also required for nodulation. This finding uncovers an important molecular mechanism that controls the establishment of nodulation and is associated with Nod-independent symbiosis
Efficiently recording of sow’s activity patterns through embedded computer vision
No full textInternational audienceThe assessment of a sow’s maternal behavior relies on manual annotations which are time consuming and are susceptible to an observer’s bias. This maternal behavior and particularly the level of activity of a sow is linked to piglet growth and to preweaning mortality. The aim of this study was to provide an overview of the data collected with the MoSBReal device, a user-friendly tool that automatically records changes in sow postures during their stay in the farrowing unit. Thirty devices (60 cameras) were installed in 10 selection farms to collect images from Landrace and Large-White sows. In total, 168,589 images coming from 275 sows were collected over 8 postures: kneeling, standing, sitting, lying on their left or right side with or without showing their udder and ventrally. A classification model, based on YOLO v11, was trained on 154,780 images. The algorithm was tested on 13,809 new images and had an overall precision of 91.2%, from 83% to 98% depending on the posture. Using this model, the activity of 13 sows was recorded between the third day before farrowing till the tenth day following it. The activity profile of those sows was studied. The number of daily posture changes was peaking for nine sows on the day of farrowing and the day before for the other four. When looking at the time spent in each posture, we found that on the day of farrowing sows spent 53.8% of the time with the udder showing. After farrowing, sows spent significantly more time in those postures (81.45% on the next day). Through this sample some diversity of activity profile has been observed. By studying the activity profile of our 275 sows we could find a new way to improve maternal abilities and weaning performances with it
Bacterial Hsp90 promotes virulence factor production through maintenance of NRPS megaenzymes
No full textAbstract Pathogenic bacteria produce virulence factors critical to host infection. Here, we demonstrate the crucial role of the bacterial Hsp90 chaperone in the production of two major virulence factors, the colibactin genotoxin in Escherichia coli and the pyoverdine siderophore in Pseudomonas aeruginosa . Colibactin, a hybrid polyketide/non-ribosomal peptide (PK-NRP), and pyoverdine, a non-ribosomal peptide (NRP), are metabolites produced by complex biosynthetic pathways involving large cytoplasmic enzymes called megasynthases. Using comparative proteomics, we found that megasynthase abundance was markedly reduced in hsp90 deletion mutants of E. coli and P. aeruginosa compared to wild-type strains. This reduction was independent of transcriptional or translational regulation. We further revealed an interplay between Hsp90 and the HslUV protease in controlling megasynthase levels. Remarkably, we found that Hsp90 stabilizes additional NRP and PK-NRP megasynthases, suggesting a general role for Hsp90 as a chaperone of these enzymes. These findings open new avenues for enhancing the biosynthesis of complex metabolites for biotechnological applications through proteostasis modulation, and may also have implications for combating bacterial infections
Differentiated short- and long-term impacts of a starter stimbiotic supplementation on gut health in broilers fed wheat and rye-based diets at homeostasis and under Eimeria tenella challenge
No full textInternational audienceThe postnatal period, covering roughly the first 10 days post–hatch, is critical for early development of the digestive tract in poultry. This period is characterized by high plasticity of the digestive tract, offering a unique window in which to shape digestive phenotypes toward improved nutrient absorption efficiency, enhanced gut health, and optimized microbiota composition. Feed additives, such as xylanase and xylo-oligosaccharides (XOSs), are known to modulate digestive physiology, especially the gut microbiota, which could, in turn, influence the outcome of infections within the gastrointestinal tract. The aim of this study was to assess the effects of a stimbiotic (STB; a combination of xylanase and XOSs) supplementation provided either during the starter, the grower, or during both periods in the context of an Eimeria tenella challenge, focusing on growth performance, ileal monomeric sugar residues, cecal metabolome and microbiota composition. From 0 to 23 d, a total of 192 chicks were assigned to 8 different treatments in a 2 × 2 × 2 factorial design. Two levels of stimbiotic (0 or 100 g/t), two periods of supplementation (starter or grower) and two challenge statuses (unchallenged or E. tenella challenged at d 16) were tested. During the starter period, STB supplementation tended to enhance average daily gain (P = 0.052) and significantly reduced the abundance of two Lachnospiraceae genera (P < 0.001; P = 0.030), accompanied by decreased concentrations of two short-chain fatty acids (SCFAs) in the caecal content (P = 0.029; P = 0.015) at d 9. In the ileum, STB supplementation reduced the concentration and proportion of soluble sugars (P = 0.006). By the end of the grower period at d 23, starter STB supplementation resulted in increased abundance of two genera within the family Lachnospiraceae (Lachnospiraceae ruminococcus, P = 0.043; Lachnospiraceae anaerostipes, P = 0.013) and elevated production of butyrate and acetate (P = 0.042; P < 0.001). Under E. tenella challenge, during the grouper period, STB supplementation maintained growth performance at levels comparable to unchallenged chickens (P = 0.027). In conclusion, STB supplementation influences microbial composition and fermentation, with lasting effects resulting from post–hatch feeding. These findings support the use of STB to improve the resilience of chickens under pathogenic challenges
Superspreading potential of SARS-CoV-2 across multiple infection generations
No full textInternational audienceBackground: Early during the coronavirus disease 2019 pandemic, the first patients to be identified as the source of infection in the clustered outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were labeled superspreaders in South Korea. However, the extent to which superspreading potential varies across different infection generations remains unclear. This study aims to estimate SARS-CoV-2 superspreading potentials across different infection generations from the largest clustered outbreak of the SARS-CoV-2 wild type in Seoul, South Korea, 2020.Methods: We retrieved the infector-infectee line list data on an outbreak occurred between May 6 and June 5, 2020. To evaluate the superspreading potential (k), we fitted the offspring distributions that had been acquired by counting the number of observed secondary infections for each case and each generation into negative binomial distributions.Results: The outbreak yielded a k value of 0.18 (95 % confidence interval [CI]: 0.13-0.27) and similar superspreading potentials across the different infection generations. Regarding the superspreading potential in each generation (i.e., individuals' heterogeneity across different generations), k was estimated to be 0.27 (95 % CI: 0.15-0.51), 0.14 (0.03-0.23), 0.10 (0.01-0.17), 0.55 (0.12-5.80 ×105), and 0.19 (0.07-0.73) for the first, second, third, fourth, and fifth or more generations, respectively.Conclusions: Our findings revealed no significant variations in the superspreading potential of SARS-CoV-2 across cases from different infection generations in the clustered outbreak. Assessing superspreading potential during the epidemic is necessary to refine epidemic modeling and enhance public health understanding of the transmission dynamic of epidemics.Keywords: Heterogeneity; Korea; Overdispersion; SARS-CoV-2; Stigmatization; Superspread; Superspreader; Transmission
