Portail des publications scientifiques de VetAgro Sup
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Wildlife ecotoxicology of plant protection products: knowns and unknowns about the impacts of currently used pesticides on terrestrial vertebrate biodiversity
No full textInternational audienceAgricultural practices are a major cause of the current loss of biodiversity. Among postwar agricultural intensification practices, the use of plant protection products (PPPs) might be one of the prominent drivers of the loss of wildlife diversity in agroecosystems. A collective scientific assessment was performed upon the request of the French Ministries responsible for the Environment, for Agriculture and for Research to review the impacts of PPPs on biodiversity and ecosystem services based on the scientific literature. While the effects of legacy banned PPPs on ecosystems and the underlying mechanisms are well documented, the impacts of current use pesticides (CUPs) on biodiversity have rarely been reviewed. Here, we provide an overview of the available knowledge related to the impacts of PPPs, including biopesticides, on terrestrial vertebrates (i.e. herptiles, birds including raptors, bats and small and large mammals). We focused essentially on CUPs and on endpoints at the subindividual, individual, population and community levels, which ultimately linked with effects on biodiversity. We address both direct toxic effects and indirect effects related to ecological processes and review the existing knowledge about wildlife exposure to PPPs. The effects of PPPs on ecological functions and ecosystem services are discussed, as are the aggravating or mitigating factors. Finally, a synthesis of knowns and unknowns is provided, and we identify priorities to fill gaps in knowledge and perspectives for research and wildlife conservation
Stereoselective bioaccumulation of chiral anticoagulant rodenticides in the liver of predatory and scavenging raptors
No full text2/3/1International audienceSecond -generation anticoagulant rodenticides (SGARs) are persistent chiral pesticides used to control rodent populations. Raptors are protected species and may be exposed through the ingestion of rodents contaminated with SGARs. Commercial formulations of SGARs are a mixture of four stereoisomers (E1, E2, E3, E4): the cis- and trans-diastereoisomers are each a racemic mixture of two enantiomers. In this study, the residue levels of all SGARs (bromadiolone, difenacoum, brodifacoum, difethialone, flocoumafen) were evaluated in the liver of 529 raptor carcasses. All species (n = 18) and 75 % of individuals (n = 396) were SGAR positive and 29 % (n = 154) had summed hepatic concentrations above 100 ng/g ww. Concentrations were higher for predators with facultative scavenging behaviors than for predators and obligate scavengers. Bromadiolone, brodifacoum and difenacoum had equivalent hepatic prevalence (between 48.9 and 49.9 %), and difethialone was detected less frequently (31.7 %). Concentrations and enantiomeric fractions of the four stereoisomers of all SGARs are described in to demonstrate the biological enantioselectivity of these chiral pesticides in the food chain. A difference was observed between the proportions of SGARs diastereoisomers and stereoisomers in the liver of all raptor species and in commercial baits. The enantioselective bioaccumulation of E1-trans-bromadiolone, E3 -cis brodifacoum, E1-cis-difenacoum and E3-cis-difethialone was characterized and represented 96.8 % of total SGARs hepatic residues. While hepatic concentrations were heterogeneous, the proportions of stereoisomers and diastereoisomers were homogeneous with no inter -individual or inter -species differences (only E1-transbromadiolone is present in hepatic residues). However, proportions of brodifacoum stereoisomers and diastereoisomers were more scattered, probably due to their slower elimination. This could provide an opportunity to date the exposure of individuals to brodifacoum. We highlight the need to consider each SGAR as four molecular entities (four stereoisomers) rather than one. These findings suggest new commercial formulations with the less persistent stereoisomers could reduce secondary exposure of non -target species
Phosphocalcic metabolism and its potential association with biomarkers of kidney disease in dogs with spontaneous hyperadrenocorticism
No full text3International audienceThe pathogenesis of increased serum phosphate concentration and proteinuria in dogs with spontaneous hyperadrenocorticism (HAC) is unclear. A potential link between proteinuria and calcium/phosphate metabolism has never been studied in dogs with HAC. The aims of the study were: (1) To evaluate calcium/phosphate metabolism in dogs with spontaneous HAC and compare to healthy dogs as well as to dogs with non-HAC illness; (2) to look for associations between markers of calcium/phosphate metabolism and biomarkers of kidney disease in dogs with HAC. Fifty-four dogs were included in the study, classified as HAC (n=27), non-HAC disease (n=17), and healthy (n=10). Serum calcium, phosphate, 25(OH)Vitamin D, 1,25(OH)2Vitamin D, plasma intact parathyroid hormone concentration (iPTH), FGF23, and urinary fractional excretion of calcium and phosphate were evaluated in all dogs at diagnosis and compared between each group. The correlation between these variables and urine protein-to-creatinine ratio (UPC) and urinary N-acetylglucosaminidase-to-creatinine ratio (uNAG/C) was evaluated in the HAC group. Medians [range] of serum phosphate concentration, urinary fractional excretion of calcium (FE(Ca)), and iPTH were significantly higher in dogs with HAC than in dogs with non-HAC illness (P<0.01) and healthy dogs (P<0.01). Increased 1,25(OH)2Vitamin D/25(OH)Vitamin D was also observed (P<0.001). In HAC group, UPC was significantly negatively correlated with 25(OH)Vitamin D (r(s): -0.54; P<0.01). Urinary NAG/C was significantly positively correlated with serum phosphate (r(s): 0.46; P=0.019). Increased serum phosphate, urinary excretion of calcium, and hyperparathyroidism were observed in dogs with HAC. Vitamin D metabolism may be shifted towards increased 1-alpha hydroxylation
Enhancing the lipid stability of foods of animal origin using edible packaging systems
No full text1/3International audienceFoods of animal origin are prone to oxidation due to their high lipid content and fatty acid profile. Edible packaging systems have evolved as a new way of preserving animal-derived foods and have been reported to retard lipid oxidation using antioxidant molecules from side-streams, waste, and agricultural by-products. Studies have evaluated previously undocumented film materials and novel bioactive molecules as additives for edible packaging for animal-derived foods. However, none of the studies is specifically focused on evaluating the packaging systems available for enhancing lipid stability. This paper thoroughly examines and discusses the application of edible packaging containing novel antioxidant molecules for controlling the lipid oxidation of animal-derived foods. The paper analyses and interprets the main findings of the recently published research papers. The materials and active principles used for enhancing lipid stability have been summarised and the underlying mechanisms discussed in detail. Studies should aim at using cheaper and readily available natural ingredients in future for the production of affordable packaging systems
Regulatory framework for the assessment of the impacts of plant protection products on biodiversity: review of strengths and limits
No full text2/1International audienceThe placing of plant protection products (PPPs) on the market in the European Union is governed by numerous regulations. These regulations are among the most stringent in the world, however they have been the subject of criticisms especially because of the decline in biodiversity. The objectives of this work were to review (1) the functioning and actors involved in the PPP framework processes, (2) the construction of the environmental risk assessment focused on biodiversity, and (3) the suggested ways to respond to the identified limits. Both literature from social sciences and ecotoxicology were examined. Despite the protective nature of the European regulation on PPPs, the very imperfect consideration of biodiversity in the evaluation process was underlined. The main limits are the multiplicity of applicable rules, the routinization of the evaluation procedures, the lack of consideration of social data, and the lack of independence of the evaluation. Strengths of the regulation are the decision to integrate a systemic approach in the evaluation of PPPs, the development of modeling tools, and the phytopharmacovigilance systems. The avenues for improvement concern the realism of the risk assessment (species used, cocktail effects…), a greater transparency and independence in the conduct of evaluations, and the opening of the evaluation and decision-making processes to actors such as beekeepers or NGOs. Truly interdisciplinary reflections crossing the functioning of the living world, its alteration by PPPs, and how these elements question the users of PPPs would allow to specify social actions, public policies, and their regulation to better protect biodiversity
Le rôle des collectifs d’agriculteurs porteurs de filières territorialisées dans les trajectoires de transition agroécologique des exploitations agricoles : analyse par la méthode des narrations quantifiées
No full textInternational audienceCollective action among farmers is regularly presented as a driver for the adoption of agroecological practices on farms. This study proposes to extend the analysis of relational drivers in the implementation of changes in practices beyond peer groups, by looking at their collective organization around territorialized supply chains involving other actors. More specifically, this paper proposes to study the role that this collective organization around territorial supply chains plays in the changes toward agroecological practices carried out on farms.The study of the individual farm trajectories as a chain of events is an approach that allows the understanding and analysis of changes in practices. As we are interested in coordination mechanisms based on interactions between actors as a driver for agroecological transition, we mobilize the framework and tools of social network analysis. In particular, in order to analyse the relational drivers in the trajectories of changes practices, we mobilize the relational chain approach through the method of quantified narratives. This approach allows us to understand changes in practices on farms as collective actions, through the study of relationships activated by farmers in order to have access to different types of resources during their trajectory. Thus, our work feeds the literature mobilizing the method of quantified narratives for the analysis of farm transition trajectories, which we modulate by focusing on the trajectory of a particular cropping system analysed through the agronomic and socio-economic principles of agroecology. We conducted semi-structured interviews with eight farmers who are members of a territorial organic wheat-flour- bread supply chain collective that includes a miller and a baker, all located in the plain of Limagne (Puy-de-Dôme, France). Following these interviews focused on their changes in wheat-growing practices, we identified five phases of agronomic and socio-economic coherence in their trajectories, that we evaluated through the prism of the agroecological principles. We then identified the relationships activated by the farmers to access the various resources needed to carry out the changes in practices during these different phases. Based on their trajectories, a typology of farms was created. This typology helps to understand the different roles played by farmers’ collectives developing territorial supply chains in the different types of farms, by analysing during which phases of the trajectory they intervene, to provide access to which resources, in articulation with which other actors. Although the interests for participation vary between the different types of farms, it appears that the farmers’ collective developing territorial supply chains systematically give access to commercial, cognitive, social and material resources. As a result, they favour access to strategic resources on the farms, making it possible to couple changes in agricultural practices and their economic valorisation. These resources contribute to a change in the farmers' posture during their trajectory, moving from a role of raw material producers to a role of co-designers of agroecological products.L'action collective entre agriculteurs est régulièrement présentée comme un levier pour la mise en oeuvre de changements de pratiques agroécologiques dans les exploitations agricoles. Cette étude propose d'ouvrir l'analyse des déterminants relationnels dans l'adoption de changements de pratiques au-delà des groupes de pairs en s'intéressant à leur organisation collective autour de filières territoriales faisant intervenir d'autres acteurs. Pour ce faire, la méthode des narrations quantifiées a été mobilisée dans le cadre d'entretiens semi-directifs menés auprès des 8 agriculteurs membres d'un collectif filière territoriale intégrant un meunier et un boulanger. L'analyse de ces trajectoires a permis la création d'une typologie des fermes favorisant la compréhension du rôle que joue le collectif filière territoriale dans les changements de pratiques menés par ses différents membres. Bien que les intérêts pour la participation au collectif varient entre les différents types de fermes, il ressort que le collectif donne systématiquement accès à des ressources tant commerciales, que cognitives, sociales et matérielles. De ce fait, le collectif favorise l'accès à des ressources stratégiques dans les exploitations agricoles permettant de coupler la mise en oeuvre de changements de pratiques agricoles et leur valorisation économique. Ces ressources contribuent à un changement de posture des agriculteurs au cours de leur trajectoire, passant d'un rôle d'exécutants producteurs de matières premières à un rôle de coconcepteurs de produits agroécologiques
Principales dermatoses environnementales, endocriniennes et tumorales chez les rongeurs
No full textNational audienceNon-infecious rodent skin diseases are mainly of environmental (pododermatitis, fur-chewing), endocrine (hyperadrenocorticism, ovarian cysts) or tumoral origin.Diagnostic sampling is the same as in dogs and cats and helps identify infectious complications.Specific husbandry conditions and environmental needs of rodents have to be considered since they can be linked to dermatoses. Finally, pharmacokinetic and pharmacodynamic studies on rodents are rare. Thus, the used drugs are based on empirical data, observations and experience.Les dermatoses non infectieuses des rongeurs sont principalement d'origine environnementale (pododermatite, toilettage excessif), endocrinienne (hypercortisolisme, kystes ovariens) ou tumorale.Les examens complémentaires nécessaires au diagnostic sont similaires à ceux réalisés chez les carnivores domestiques et servent également à identifier des complications infectieuses. Chaque rongeur ayant des conditions de vie spécifiques, celles-ci sont importantes à déterminer compte-tenu de leur impact potentiel sur le développement de certaines dermatoses. Les traitements et les dosages des médicaments sont souvent issus de données empiriques et de l'expérience des praticiens, car il existe peu d'études de pharmacocinétique ou de pharmacodynamie pour ces espèces
Towards a tool based on the adoption of ecological farming practices to asses overall performance: Application with the French RICA database
No full textInternational audienceThe LIFT typology-tool materialises the LIFT farm typology developed in WP1. The tool is based on the LIFT typology’s concepts, rationale and protocols (in particular the one for Farm Accountancy Data Network (FADN) data) (Rega et al., 2021). The main objective of the tool is to assign a farm to one of the ecological types identified in the LIFT farm typology. The tool gives a graphical snapshot of the current situation of a farm in terms of ecological practices, and offers the possibility to ex-plore effects of changing input variables. Further, the LIFT typology-tool enables the comparison of performances covering the economic, social and employment, as well as environmental dimensions of farms belonging to different ecological types, and also considering bioregions and types of farm-ing. It is a free and user-friendly tool that was built using the programming language R and in partic-ular the R-package “shiny”. A first test was applied on the RICA database for France. Results show that standard farming system dominates with 70% of the sample. Among the 30% of farms having greening practices, the distribution is well balanced between organic farming, low input farming, integrated/circular farming. Only 1% are considered as agroecological farms. Then, this distribution enables us to depict whether ecological farms perform differently and have different trade-offs and synergies than less ecological farms. Besides supplying a functional tool for agricultural advisors to discuss with farmers how they can improve the farm's overall performance, these insights con-tribute to the evolution from FADN/RICA to a Farm Sustainability Data Network (FSDN/RIDEA)
A framework to study the resilience of dairy herds to climate change from on-farm data
No full textInternational audienceClimate change is known to challenge mountain livestock farming systems through its impact on forage resources availability. However, information about their vulnerability to heat waves is meager. Previous studies showed that heat waves can severely affect dairy cows’ welfare and activity, their reproductive success and milk yield. Thus, the ability of mountain dairy herds to cope with heat episodes is worth to be addressed. The objective is to develop a framework to examine the resilience of dairy herds to heat waves from milk data gathered on farms.The study was carried out on 500 dairy herds located in a mountain area (Puy de Dôme, France), covering a period of 22 years. Longitudinal data available for each herd concerned productive (milk yield) and reproductive (calving to calving interval) performances along with cows longevity. Weather data (daily temperatures and humidity) for the same period and area , were used to calculate the daily temperature humidity index (THI) at a local scale. Heat stress events (HSE) were identified when THI was both higher than 68 and higher than weekly average for at least three consecutive days. Finally, yearly cumulative sums for both duration and levels of HSE were calculated. Dairy herd resilience was assessed through the ability of a given herd to maintain yearly performances relatively stable when experiencing HSE (being minimally affected or going back rapidly to equilibrium state). Then, resilient and non-resilient dairy herds were contrasted in terms of their characteristics (milk yield, breeds, calvings and lactations distribution).The development of such a framework may be useful to identify levers of resilience at the herd level that would ultimately help dairy farmers better dealing with the expected increase in frequency and intensity of HSE
