Portail Hal-l'Institut Agro Rennes-Angers
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Tree for dairy farms' resilience to extreme weather events : first insights using a subjective approach
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How farmers communicate with society about their job and livestock's pratices?
No full textInternational audienceThe growing disconnect between animal farming and society has been exacerbated by media portrayals, leading to widespread misconceptions about farming practices. A student’s project, part of the CASDAR ENTR'ACTES research project, aims to reestablish the link between livestock farmers and the public by examining the communication efforts of livestock farmers. The main objectives are to identify the profiles and motivations of farmers who engage in communication initiatives and to assess how these efforts influence public perceptions. A qualitative approach using semi-structured interviews with 15 farmers across France explored their communication methods and challenges. The sample covered diverse animal production—dairy, poultry, and pig farming—across various regions. The study's core hypothesis suggests that the type of farming, its practices, and the local context influence communication strategies. The findings reveal that farmers who engage in public communication share a strong commitment to transparency and education, aiming to demystify their work and address societal concerns (animal welfare, environmental impacts). They use a mix of direct channels (farm visits, events) and indirect channels (social media, websites) to reach diverse audiences, ranging from local consumers to urban residents. The motivations for communicating are diverse and often combined: to secure income or a market, to foster positive public perceptions and build trust with consumers. However, challenges such as time constraints, financial pressures, and the complexity of public controversies limit the scope and effectiveness of these initiatives. Results suggest that communication is most effective when farmers are open and sincere, discussing both the benefits and challenges of modern farming. Despite the obstacles, many farmers think it is essential to maintain good relations with their community and improve society's understanding of agriculture. This study will provide guidance for future farmers wishing to embark on this path
Tracking the schools: a review of approaches to address knowledge gaps in the migratory ecology and habitat use of Canadian forage fishes
No full textInternational audienceForage fishes play a vital role to marine ecosystems by linking lower trophic levels to top predators and serving as key economic and food resources for commercial and subsistence fisheries. Despite their significance, knowledge of forage fish movement throughout their life cycle in Canadian waters remains limited, hindering effective management and conservation. This study synthesises current knowledge of the movement ecology of seven of Canada's key forage fish species: capelin (Mallotus villosus), Atlantic mackerel (Scomber scombrus), Atlantic herring (Clupea harengus), Pacific herring (Clupea pallasii), Arctic cod (Boreogadus saida), eulachon (Thaleichthys pacificus), and sand lances (Ammodytes spp). We assess the methodologies used to study their movements, spanning from traditional capture-mark-recapture techniques and fisheries-dependent or independent surveys to advanced approaches such as acoustic telemetry and natural chemical tracers. Significant knowledge gaps persist in remote locations where research is limited, as well as for non-commercially exploited species and specific life phases such as overwintering, which remain poorly understood across all species. To address these knowledge gaps, we underscore the value of combining conventional and modern methodologies. Additionally, we advocate for incorporating indigenous knowledge, such as the holistic knowledge of Inuit (Inuit Qaujimajatuqangit), and community-based observations to enrich insights. Implementing these recommendations and advancing our knowledge of forage fish migration is crucial for predicting the impacts of environmental change on fish movement and for ensuring their sustainability, as well as the ecosystems and fisheries they support
A dynamic biomimetic in vitro model that integrates stomach biomechanics to monitor gastric digestion of milk
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Enhancing plant disease resistance through intra and interspecific diversification
No full textInternational audienceAgricultural intensification has led to a significant reduction in cultivated biodiversity, with global food production increasingly dependent on a limited number of species. This trend has contributed to climate change, biodiversity loss, and human health concerns. One major consequence of crop genetic homogenization is the increased vulnerability of agricultural systems to pests, diseases, and weeds at both field and landscape levels. In contrast, diversification has emerged as a promising strategy for sustainable, pesticide-free agriculture by enhancing resilience and stability. At the national scale, diversification broadens crop variety, while at the farm level, techniques such as extended crop rotations, cover cropping, intercropping, and cultivar mixtures improve pest and disease control.The French collaborative project MoBiDiv explores the role of diversification in influencing the establishment and evolution of plant diseases, pests, and weeds. Specifically, we aim to assess how diversification enhances the durability of disease resistance and alters disease susceptibility within mixed cropping systems. Additionally, we seek to determine whether intra-plot diversification drives genetic co-selection between interacting plants.To evaluate the impact of intercropping on fungal disease incidence, we conducted field trials using two intercropping systems: (i) wheat-perennial prairie, and (ii) wheat-pea. Disease assessments focused on key fungal pathogens, including septoria tritici blotch in wheat, and anthracnosis in pea. Our findings demonstrated that intercropping effectively reduced disease severity, particularly in anthracnosis affecting pea. However, no significant effect was observed on wheat fungal diseases in the wheat-pea system, while septoria incidence was lower in wheat intercropped with prairie. This highlights the potential of certain intercropping combinations in mitigating specific disease pressures.To further investigate the genetic mechanisms underlying these effects, we analyzed potential co-selection between plants that might influence susceptibility to fungal diseases in wheat intraspecific mixtures. We conducted the first co-Genome Wide Association Study (co-GWAS) between two interacting plants and tested whether loci involved in inter-individual interactions exhibited signatures of selection. We calculated Tajima’s D values to detect selection traces, expecting co-selected loci to show more negative values than control regions. Linkage disequilibrium (LD) was also assessed between interacting loci, hypothesizing that co-selected regions would exhibit high r² values. Finally, we compared intra- and inter-subgenome interactions, postulating that co-selection would primarily occur within sub-genomes in ancestral wheat lines predating polyploidization. Our analyses did not detect clear evidence of co-selection. This suggests that intra-plot diversification influences disease suppression primarily through eco-physiological mechanisms rather than co-evolutionary genetic adaptation. Understanding the impact of these underlying mechanisms on disease reduction is important to optimize diversification strategies and resistance management
Measuring juvenile habitat quality for fishes and invertebrates
No full textInternational audienceIdentifying the role of marine and estuarine habitats in supporting fish and invertebrate populations during vulnerable juvenile life stages is essential to achieve effective conservation and fisheries management. There remains general agreement that: (i) the quality of juvenile habitat is best measured as the contribution of juveniles to adult populations (here "juvenile-adult contribution") and (ii) this contribution may be measured directly or inferred from habitat-specific abundance, growth and survival. Obtaining effective estimates of juvenile habitat quality using these four metrics, however, is challenging. Through a systematic review of approaches to measure juvenile habitat quality, we critically evaluate current abilities to identify key habitats and provide recommendations for future work. We found that research in this area remains dominated by measurements of abundance (85% of studies) and, to a lesser extent growth (51% of studies), with limitations in the spatiotemporal resolution and extent of sampling. Relatively few approaches are available to measure survival and juvenile-adult contribution. Knowledge of juvenile habitat quality is further limited by restricted coverage of geographic areas, taxonomic groups and habitats. Based on our analysis of 874 studies over the past ca. 50 years, we provide five recommendations for enabling juvenile habitat research to support fisheries and conservation management better in future
Le RMQS-Biodiversité : une grande avancée pour la connaissance de la biodiversité des sols de France
No full textInternational audienceLa biodiversité des sols est fondamentale pour le fonctionnement des écosystèmes, mais reste sous-représentée dans les politiques de conservation et la surveillance à grande échelle. Le RMQS-Biodiversité propose un ensemble de protocoles pour étudier la biodiversité des sols intégré au Réseau de mesures de la qualité des sols (RMQS). Il a déjà été déployé sur une centaine de sites jusqu’en 2024 et les premiers résultats démontrent un potentiel pour la recherche en écologie des sols. L’analyse multi-taxon, des micro-organismes à la macrofaune des sols s’appuie sur la collecte d’échantillons par diverses méthodes : un échantillon composite, des pièges barber laissés 28 jours dans la parcelle, des carottes mésofaune et des test bêches avec aspersion de moutarde.En 2024, l'identification des taxons (autant que possible au niveau de l'espèce et sinon au niveau du genre ou de la famille) sur 69 sites a permis de repérer divers taxons largement distribués ainsi que d'autres plus rares sur le territoire métropolitain.L’analyse plus précise des Carabidae sur cette étude montre que le type d’habitat (fermé ou ouvert) influence le dimorphisme sexuel chez ces insectes, résultat déjà observé dans de précédentes études. L’échantillonnage sur le RMQS-Biodiversité se poursuit pendant les 3 prochaines années, les résultats de ces nouvelles campagnes viendront consolider ces premières approches
Genetic Control of Root Morphology in Rapeseed Recombinant Inbred Lines Grown Under Contrasting Nitrogen Levels
No full textInternational audienceNitrogen fertilization is critically important for the growth of oleaginous rapeseed ( Brassica napus L.). Optimizing root morphology for improved soil nitrogen uptake can reduce the fertilizer need, leading to more cost‐effective and sustainable agricultural practices. This study investigated the genetic basis of root traits using two connected populations of recombinant inbred lines, grown hydroponically with 0.2 or 5 mM nitrate levels. Low nitrate increased the root‐to‐shoot biomass ratio and promoted primary root growth in both populations, while lateral root responses varied depending on the population. Significant genotype × nitrate interactions were observed, explaining a larger proportion of phenotypic variance than genotype alone. Heritability estimates ranged from moderate to high under both nitrate levels. QTL mapping was conducted using both population‐specific and multi‐parental models, applied separately under each nitrate level, as well as for nitrate response. A total of 36 QTLs were identified. Notably, five chromosomal regions were shared between populations, and one region remained stable across both nitrate levels and mapping strategies. These regions contained candidate genes like A03p54730 ( CYTOKININ RESPONSE FACTOR 2 ), A03p54920 ( NIN LIKE PROTEIN 7 ) and A06p12530 ( LOB DOMAIN‐CONTAINING PROTEIN 3 ), making them promising selection targets for optimizing root morphology in rapeseed crops
Milk gel formation and properties: impact of whey protein aggregates
No full textWhey protein aggregation has been used in cheesemaking to increase the yield. This review examines rennet- and acid-induced milk gelation in the presence of whey protein aggregates. In situ aggregates, formed during milk heating, impair enzymatic gelation by hindering casein micelle aggregation but enhance acid gel strength. Ex situ aggregates, pre-formed and added in milk, exhibit various morphologies. They alter gelation dynamics and gel properties differently compared to in situ aggregates. However, this research area remains highly underexplored. Physics-based models may give insights on underlying mechanisms of gel formation but lack specificity for casein micelle dynamics and show limits in integrating whey protein aggregates. Future research must prioritise mechanistic insights into interactions between whey protein aggregates and casein micelles. Such advances could optimise ex situ aggregates structure and properties for innovative cheesemaking, balancing texture, nutrition and yield
How do whey protein aggregates modify the coagulation properties of milk?
No full textInternational audienceThe enzymatic gelation of milk takes place following four key-steps (hydrolysis; flocs aggregation; strand formation; aging and syneresis). Milk is often preheated, inducing the aggregation of whey protein (WP) in order to increase the yield of dairy products. While the literature on the formation and structure of WP aggregates is abundant, their role in the casein micelles aggregation and underlying mechanisms is not fully elucidated, especially when independently formed WP aggregates are added in milk. Our objective was to study the effect of WP aggregates on the milk gelation by SAOS (Small-Angle Oscillatory Shear), CSLM (Confocal Scanning Laser Microscopy), and particle aggregation quenching. At the same storage modulus, milk gels with increasing concentration of WP aggregates displayed the same rheological signatures in frequency and oscillation stress sweep, though the time needed to reach the same storage modulus value was longer. These gels featured smaller serum pores and kept a higher water content after syneresis. Not only the gelation was slowed down, but its mechanisms was also changed, especially during the primary aggregation of casein micelles, strands aging, and serum pore formation