Free-range eggs dioxin contamination assessment: comparison between a simple model and in situ measurements to determine a maximum egg frequency consumption

Dioxins (polychlorinated dibenzodioxins - PCDDs) and furans (polychlorinated dibenzofurans - PCDFs), are a family of aromatic organochlorine molecules whose primary origin of their emission is industrial processes requiring a combustion process. These compounds are very lipophilic, stable and not very biodegradable. These persistent organic pollutants accumulate in fatty tissue. For this reason, food is one of the main source of exposure to PCDD/Fs in our daily environment. Following a large PCDD/Fs soil contamination in Lausanne (Switzerland), a first report evaluated the risk of different exposure scenarios. Poultry houses on contaminated soil represent a risk of contamination by ingestion of PCDD/Fs contaminated eggs. Chickens peck on contaminated land ingest soil. The PCDD/Fs absorbed are found in their fat mass and are eliminated through the eggs. The objective of the study was to evaluate the expected concentrations in eggs as a function of the concentrations in the soil and express recommendation on the frequency of ingestion to remain below the acceptable daily intake. We fitted a PCDD/Fs toxicokinetic model in hens to evaluate the sensitivity of the different parameters. In order to validate the model, we sampled eggs and soil from five chicken houses in the contaminated area. The PCDD/Fs in eggs were extracted by liquid-liquid extraction and quantified by gas chromatography high resolution mass spectrometry. The PCDD/Fs from the soil were extracted using an Accelerated Solvent Extraction and then quantify by gas chromatography high resolution mass spectrometry. The results from the model were compared to the measured concentrations. The model is conservative since there is a tendency to overestimate the real concentrations. A rapid elimination phase during the first days is followed by first order kinetics. Overall, the half-life is 50 days. After 200 days, an equilibrium is reached and the concentrations in the eggs are stable. The parameters that influence the concentrations measured in the eggs are: the soil concentration, the geophagy (amount of soil ingested by the hen during pecking), the age of the hen (or its duration on the contaminated soil) and the egg laying efficiency. The geophagy parameter is the most difficult to predict. In order to limit health risks, we would recommend avoiding eggs from hens if they are pecking on soil above 50 ng Toxic Equivalent (TEQ)/kg soil. Below this concentration, it is recommended to ensure a good vegetation cover to limit geophagy and depending on the soil concentration to reduce the frequency of egg consumption

Analyse des patrimoines de données géographiques nationaux: Comparaison de trois infrastructures nationales de données géographiques (France, Brésil, Bolivie)

International audienceDue to the dual impact of systems interoperability and changes in the legal framework, institutional spatial data tends to become more and more accessible through widespread deployment of spatial data infrastructures (SDI). Comparative analysis of the content of three national SDI (France, Bolivia, Brazil) reveals a few tendancies. This contribution's originality lies in using SDI not as an aid to research but as a true object of study. Metadata analysis of three national catalogs offers a way to reconsider the logics of both formalisation and knowledge diffusion through territories.Par le double effet de l'interopérabilité des systèmes et de l'évolution du cadre légal, les patrimoines de données géographiques institutionnelles tendent aujourd'hui à être de plus en plus facilement accessibles à travers la mise en place généralisée d'infrastructures de données géographiques (IDG). L'analyse comparée du contenu de trois IDG nationales (France, Bolivie, Brésil) permet alors de révéler quelques tendances. L'originalité de cette contribution est donc de faire des IDG non pas un support à la recherche d'information mais un véritable objet de recherche. L'analyse des métadonnées des trois catalogues nationaux nous permettra alors de réinterroger les logiques de formalisation et de diffusion des connaissances sur les territoires

Supplémentation en colza ou en lin de rations à base d’herbe chez la vache laitière durant deux lactations consécutives : effets sur les performances zootechniques et la composition fine en acides gras du lait

Addition of oilseed supplements to dairy cow diets for 1 to 3 months may improve the milk nutritional quality, but detrimental effects on animal performance may also occur. However, data is scarce on long-term effects of these nutritional strategies. The objective of this thesis was to quantify the effects of extruded linseed and three forms of rapeseed-derived supplements on dairy cow performance and detailed milk fatty acid composition, during 2 consecutive lactations. Basal diet was conserved grass during winter and pasture during summer. Oilseed supplements effects persist within each period (winter and summer) and are repeatable between the 2 summer periods. Long-term effects observed over 2 consecutive lactations are similar to those observed during short-term (1 to 3 months) studies. These oilseed-derived supplements not improve dairy cow performance, but decrease the milk protein content in some instances, especially during winter period. Nevertheless, oilseed supplementations reduce milk saturated fatty acid content and increase milk content in oleic acid and with linseed in α-linolenic acid. Such changes could be considered as an improvement of the milk nutritional quality. However, extruded linseed and fat-rich rapeseed meal increase milk trans fatty acid content, and oilseed supplements often decrease milk rumenic acid at pasture. Isomer distribution of cis and trans unsaturated fatty in milk fat is dependent on the oilseed nature and diet starch content, but not on the rapeseed form. However, rapeseed form modifies the magnitude of observed effects. Furthermore, the detailed analyses of milk fatty acid profile allowed to explore conjugated linoleic and linolenic fatty acids metabolism, and their relationship with mammary lipogenesis.L’apport de graines oléagineuses dans la ration de la vache laitière pendant 1 à 3 mois pourrait améliorer la qualité nutritionnelle du lait, mais également pénaliser dans certains cas les performances zootechniques. Peu de données sont disponibles sur les effets de ces stratégies alimentaires sur de plus longues périodes. L’objectif de cette thèse est de quantifier au cours de 2 lactations consécutives, les effets de supplémentations en lin ou en trois différentes formes de colza de rations à base d’herbe conservée en hiver et pâturée en été sur les performances zootechniques de la vache laitière et la composition fine en acides gras du lait. Les effets des suppléments étudiés persistent au sein de chaque période (hiver et été) et sont répétables d’un été à l’autre. Ils sont par ailleurs similaires à ceux observés lors d’études de durée plus courte (1 à 3 mois). Ces stratégies ne permettent pas d’améliorer les performances zootechniques et diminuent parfois le taux protéique du lait, notamment en hiver. Toutefois, elles réduisent les teneurs du lait en acides gras saturés au profit de l’acide oléique et, dans le cas du lin de l’acide α-linolénique. Ces modifications peuvent être considérées comme une amélioration de la qualité nutritionnelle du lait. Cependant, le lin extrudé et le tourteau de colza gras augmentent les acides gras trans et les suppléments diminuent souvent l’acide ruménique du lait au pâturage. La distribution des isomères des acides gras insaturés cis et trans du lait dépend du type de graine et du niveau d’amidon de la ration, mais pas de la forme d’apport du colza, qui influence toutefois l’amplitude des effets observés. Par ailleurs, l’analyse détaillée du profil en acides gras du lait a permis de mieux comprendre le métabolisme des acides linoléiques et linoléniques conjugués, en lien avec la lipogenèse mammaire

Rapeseed or linseed supplements in grass-based diets over two consecutive lactations : Effects on dairy cow performance and detailed milk fatty acid composition

L’apport de graines oléagineuses dans la ration de la vache laitière pendant 1 à 3 mois pourrait améliorer la qualité nutritionnelle du lait, mais également pénaliser dans certains cas les performances zootechniques. Peu de données sont disponibles sur les effets de ces stratégies alimentaires sur de plus longues périodes. L’objectif de cette thèse est de quantifier au cours de 2 lactations consécutives, les effets de supplémentations en lin ou en trois différentes formes de colza de rations à base d’herbe conservée en hiver et pâturée en été sur les performances zootechniques de la vache laitière et la composition fine en acides gras du lait. Les effets des suppléments étudiés persistent au sein de chaque période (hiver et été) et sont répétables d’un été à l’autre. Ils sont par ailleurs similaires à ceux observés lors d’études de durée plus courte (1 à 3 mois). Ces stratégies ne permettent pas d’améliorer les performances zootechniques et diminuent parfois le taux protéique du lait, notamment en hiver. Toutefois, elles réduisent les teneurs du lait en acides gras saturés au profit de l’acide oléique et, dans le cas du lin de l’acide α-linolénique. Ces modifications peuvent être considérées comme une amélioration de la qualité nutritionnelle du lait. Cependant, le lin extrudé et le tourteau de colza gras augmentent les acides gras trans et les suppléments diminuent souvent l’acide ruménique du lait au pâturage. La distribution des isomères des acides gras insaturés cis et trans du lait dépend du type de graine et du niveau d’amidon de la ration, mais pas de la forme d’apport du colza, qui influence toutefois l’amplitude des effets observés. Par ailleurs, l’analyse détaillée du profil en acides gras du lait a permis de mieux comprendre le métabolisme des acides linoléiques et linoléniques conjugués, en lien avec la lipogenèse mammaire.Addition of oilseed supplements to dairy cow diets for 1 to 3 months may improve the milk nutritional quality, but detrimental effects on animal performance may also occur. However, data is scarce on long-term effects of these nutritional strategies. The objective of this thesis was to quantify the effects of extruded linseed and three forms of rapeseed-derived supplements on dairy cow performance and detailed milk fatty acid composition, during 2 consecutive lactations. Basal diet was conserved grass during winter and pasture during summer. Oilseed supplements effects persist within each period (winter and summer) and are repeatable between the 2 summer periods. Long-term effects observed over 2 consecutive lactations are similar to those observed during short-term (1 to 3 months) studies. These oilseed-derived supplements not improve dairy cow performance, but decrease the milk protein content in some instances, especially during winter period. Nevertheless, oilseed supplementations reduce milk saturated fatty acid content and increase milk content in oleic acid and with linseed in α-linolenic acid. Such changes could be considered as an improvement of the milk nutritional quality. However, extruded linseed and fat-rich rapeseed meal increase milk trans fatty acid content, and oilseed supplements often decrease milk rumenic acid at pasture. Isomer distribution of cis and trans unsaturated fatty in milk fat is dependent on the oilseed nature and diet starch content, but not on the rapeseed form. However, rapeseed form modifies the magnitude of observed effects. Furthermore, the detailed analyses of milk fatty acid profile allowed to explore conjugated linoleic and linolenic fatty acids metabolism, and their relationship with mammary lipogenesis

Supplémentation en colza ou en lin de rations à base d'herbe chez la vache laitière durant deux lactations consécutives (effets sur les performances zootechniques et la composition fine en acides gras du lait)

L apport de graines oléagineuses dans la ration de la vache laitière pendant 1 à 3 mois pourrait améliorer la qualité nutritionnelle du lait, mais également pénaliser dans certains cas les performances zootechniques. Peu de données sont disponibles sur les effets de ces stratégies alimentaires sur de plus longues périodes. L objectif de cette thèse est de quantifier au cours de 2 lactations consécutives, les effets de supplémentations en lin ou en trois différentes formes de colza de rations à base d herbe conservée en hiver et pâturée en été sur les performances zootechniques de la vache laitière et la composition fine en acides gras du lait. Les effets des suppléments étudiés persistent au sein de chaque période (hiver et été) et sont répétables d un été à l autre. Ils sont par ailleurs similaires à ceux observés lors d études de durée plus courte (1 à 3 mois). Ces stratégies ne permettent pas d améliorer les performances zootechniques et diminuent parfois le taux protéique du lait, notamment en hiver. Toutefois, elles réduisent les teneurs du lait en acides gras saturés au profit de l acide oléique et, dans le cas du lin de l acide a-linolénique. Ces modifications peuvent être considérées comme une amélioration de la qualité nutritionnelle du lait. Cependant, le lin extrudé et le tourteau de colza gras augmentent les acides gras trans et les suppléments diminuent souvent l acide ruménique du lait au pâturage. La distribution des isomères des acides gras insaturés cis et trans du lait dépend du type de graine et du niveau d amidon de la ration, mais pas de la forme d apport du colza, qui influence toutefois l amplitude des effets observés. Par ailleurs, l analyse détaillée du profil en acides gras du lait a permis de mieux comprendre le métabolisme des acides linoléiques et linoléniques conjugués, en lien avec la lipogenèse mammaire.Addition of oilseed supplements to dairy cow diets for 1 to 3 months may improve the milk nutritional quality, but detrimental effects on animal performance may also occur. However, data is scarce on long-term effects of these nutritional strategies. The objective of this thesis was to quantify the effects of extruded linseed and three forms of rapeseed-derived supplements on dairy cow performance and detailed milk fatty acid composition, during 2 consecutive lactations. Basal diet was conserved grass during winter and pasture during summer. Oilseed supplements effects persist within each period (winter and summer) and are repeatable between the 2 summer periods. Long-term effects observed over 2 consecutive lactations are similar to those observed during short-term (1 to 3 months) studies. These oilseed-derived supplements not improve dairy cow performance, but decrease the milk protein content in some instances, especially during winter period. Nevertheless, oilseed supplementations reduce milk saturated fatty acid content and increase milk content in oleic acid and with linseed in a-linolenic acid. Such changes could be considered as an improvement of the milk nutritional quality. However, extruded linseed and fat-rich rapeseed meal increase milk trans fatty acid content, and oilseed supplements often decrease milk rumenic acid at pasture. Isomer distribution of cis and trans unsaturated fatty in milk fat is dependent on the oilseed nature and diet starch content, but not on the rapeseed form. However, rapeseed form modifies the magnitude of observed effects. Furthermore, the detailed analyses of milk fatty acid profile allowed to explore conjugated linoleic and linolenic fatty acids metabolism, and their relationship with mammary lipogenesis.CLERMONT FD-Bib.électronique (631139902) / SudocSudocFranceF

Accumulation of metallic trace elements in Reynoutria japonica: a risk assessment for plant biomass valorization

International audienceSustainable solutions aiming at limiting Reynoutria japonica invasion consist of frequent removal of its aerial biomass. The aims of this study were to measure the accumulation of metallic trace elements (MTE) in R. japonica, and to assess the ecotoxicological risk related to the valorization of the produced biomass. R. japonica fragmented rhizomes were regenerated in pots for 41 days on a control soil (CTL) or a moderately MTE-contaminated soil (POL, 3.6 mg Cd kg −1 DM). Growth traits were recorded, as well as MTE bioconcentration (BCF) and translocation factors (TF) from soil to plant organs. Whatever the MTE and plant organs, BCF remained below one (mean Cd-BCF for stem and leaf: 0.07 and 0.29 for CTL and POL, respectively), conversely to TF (until 2.2 for Cd and Ni in POL soil). When grown on the POL soil, R. japonica stem and leaf Cd content was close to the EU maximum regulatory limit for organic amendments or animal feed. Model simulations suggested that liver and kidney Cd concentrations would exceed the regulatory limit in food when adult cattle or sheep constantly ingest R. japonica grown on the POL soil over 200 to 800 days. The results of the present study will be useful to help managers in selecting efficient and safe solutions for the control of R. japonica invasion

Comparaison de trois infrastructures nationales de données géographiques (France, Brésil, Bolivie)

Par le double effet de l'interopérabilité des systèmes et de l'évolution du cadre légal, les patrimoines de données géographiques institutionnelles tendent aujourd'hui à être de plus en plus facilement accessibles à travers la mise en place généralisée d'infrastructures de données géographiques (IDG). L'analyse comparée du contenu de trois IDG nationales (France, Bolivie, Brésil) permet alors de révéler quelques tendances. L'originalité de cette contribution est donc de faire des IDG non pas un support à la recherche d'information mais un véritable objet de recherche. L'analyse des métadonnées des trois catalogues nationaux nous permettra alors de réinterroger les logiques de formalisation et de diffusion des connaissances sur les territoires.Due to the dual impact of systems interoperability and changes in the legal framework, institutional spatial data tends to become more and more accessible through widespread deployment of spatial data infrastructures (SDI). Comparative analysis of the content of three national SDI (France, Bolivia, Brazil) reveals a few tendancies. This contribution's originality lies in using SDI not as an aid to research but as a true object of study. Metadata analysis of three national catalogs offers a way to reconsider the logics of both formalisation and knowledge diffusion through territories

The use of computer tomography to estimate reticulo-rumen content in Alpine goats

International audienceEstimation of reticulo-rumen content (volume and mass) is required in ruminant nutrition to determine effects ofdiet and environment on gut filling, nutrient turnover and to model digestive processes. Reticulo-rumen content is commonly measured via a rumen cannula. Animal scientists continuously seek to refine experimental procedures by developing less invasive techniques. The objective was to compare reticulo-rumen volume assessed by computer tomography (CT) with post mortem measurement of reticulo-rumen content mass in dairy goats. Twenty Alpine dairy goats (3±0.6 years old; 226±9 DIM) with body weight ranging from 47 to 72 kg were used. Goats were housed in a free-stall barn, had free access to hay and water, and were offered 0.75 kg/d of concentrate. Goats were anesthetised and placed in an inflatable mattress before duo CT scan (Siemens, Erlange, Germany) was performed. Between 400 to 500 images were generated per goat and analysed semi-automatically (www.turtleseg.org). The volume of reticulorumen and omasum were determined separately. Each goat was slaughtered within 15 min after CT, the reticulo-rumen and omasum were weighed full and after removing the digesta, and content weights were obtained by difference. The SAS GLM procedure was used to test simple regressions between organ volume obtained with CT and digesta mass measured post mortem. Volume of reticulo-rumen and omasum determined by CT were good estimators of digesta mass measured post mortem [R2=0.72 and 0.73, residual standard deviation (rSD)=1.18 and 0.10 kg and residual coefficient of variation (rCV)=11 and 22%, respectively, n=20]. The regression was improved for omasum content when one individual with an extremely low digesta mass (22 g) was excluded (R2=0.87, rSD=0.06 kg, rCV=12%, n=19). The use of CT may constitute a promising non-invasive method to estimate volume and mass of reticulo-rumem digestive content in small ruminants. Further research is warranted to test the ability of this technique to discriminate dietary treatments that induce differential rumen fill

Estimation of empty body and carcass chemical composition of lactating and growing cattle: comparison of imaging, adipose cellularity, and rib dissection methods

International audienceThe aim of present study was to compare in vivo and post mortem methods for estimating the empty body (EB) and carcass chemical compositions of Simmental lactating and growing cattle. Indirect methods were calibrated against the direct post mortem reference determination of chemical compositions of EB and carcass, determined after grinding and analyzing the water, lipid, protein, mineral masses, and energy content. The indirect methods applied to 12 lactating cows and 10 of their offspring were ultrasound (US), half-carcass and 11th rib dual-energy X-ray absorptiometry (DXA) scans, subcutaneous and perirenal adipose cell size (ACS), and dissection of the 11th rib. Additionally, three-dimensional (3D) images were captured for 8 cows. Multiple linear regressions with leave-one-out-cross-validations were tested between predictive variables derived from the methods tested, and the EB and carcass chemical compositions. Partial least square regressions were used to estimate body composition with morphological traits measured on 3D images. Body weight (BW) alone estimated the EB and carcass composition masses with a root mean squared error of prediction (RMSEP) for the EB from 1 kg for minerals to 12.4 kg for lipids, and for carcass from 0.9 kg for minerals to 7.8 kg for water. Subcutaneous adipose tissue thickness measured by US was the most accurate in vivo predictor when associated with BW to estimate chemical composition, with the EB lipid mass RMSEP = 11 kg and R 2 = 0.75; carcass water mass RMSEP = 6 kg and R 2 = 0.98; and carcass energy content RMSEP = 236 MJ and R 2 = 0.91. Post mortem, carcass lipid mass was best estimated by half-carcass DXA scan (RMSEP = 2 kg, R 2 = 0.98), 11th rib DXA scan (RMSEP = 3 kg, R 2 = 0.96), 11th rib dissection (RMSEP = 4 kg, R 2 = 0.92), and perirenal ACS (RMSEP = 6 kg, R 2 = 0.79) in this respective order. The results obtained by 11th rib DXA scan were accurate and close to the half-carcass DXA scan with a reduction in scan time. Morphological traits from 3D images delivered promising estimations of the cow EB and carcass chemical component masses with an error less than 13 kg for the EB lipid mass and than 740 MJ for the EB energy. Future research is required to test the 3D imaging method on a larger number of animals to confirm and quantify its interest in estimating body composition in living animals