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Detecting diseases early in pig farming is a promising way to help breeders monitor animal health, reduce antibiotic use and treat sick animals in a targeted manner. This study analysed individual water and feed consumption as a function of the live weight of weaned piglets and its relation to diarrhoea. Data were collected from 15 batches of 102 piglets each, using specific automata (i.e. connected feeders, connected drinkers, automatic weighing stations, RFID ear tags), and piglet health status was monitored daily. Analysis used seven machine learning methods. Mean water and feed consumption of healthy pigs did not differ significantly among weight categories, except in week five, due to atypical water consumption by a heavy pig. In addition, mean water consumption did not differ significantly between healthy and sick piglets, either on the day that diarrhoea was observed or two days before. However, mean feed consumption of healthy piglets and those with diarrhoea did differ significantly from day 4-9 post-weaning and even 24 and 48 h before the onset of clinical signs. Nevertheless, the machine-learning methods tested did not provide effective early detection of diarrhoea, due to insufficient sensitivity and specificity of results (74% and 58%, respectively) for field use. In future studies, new parameters such as automatic measurement of body temperature or location of piglets in the pen by image analysis could improve the performance of these methods., Détection précoce des diarrhées chez les porcelets sevrés à partir des données d'abreuvement, d'alimentation et de poids La détection précoce de pathologies en élevage porcin est une piste prometteuse pour aider les éleveurs à surveiller la santé des animaux, réduire les usages d'antibiotiques et traiter de façon ciblée les animaux malades. L'objectif de cette étude est d'évaluer la valeur prédictive des consommations individuelles d'eau et d'aliment, en fonction du poids vif, pour détecter précocement l'apparition de diarrhée chez des porcelets sevrés. Quinze lots de 102 porcs, logés dans des cases équipées de nourrisseurs, abreuvoirs et bascules connectées, ont été identifiés individuellement par des boucles RFID et leur état sanitaire a été suivi quotidiennement. Les résultats ont montré que les consommations moyennes d'eau et d'aliment des porcs sains n'ont pas été significativement différentes selon leur catégorie de poids (lourd, moyen, léger), sauf en cinquième semaine en lien avec le niveau d'abreuvement atypique d'un porc lourd. Par ailleurs, aucune différence significative n'a été observée entre les consommations moyennes d'eau des animaux sains et malades, ni le jour de l'observation de la diarrhée ni deux jours avant. A l'inverse, une différence significative a été notée entre les consommations alimentaires moyennes des porcelets sains et diarrhéiques sur la première période du post-sevrage, à la fois le jour même d'apparition de la diarrhée, 24 heures et 48 heures avant. Néanmoins, les méthodes d'apprentissage automatique testées n'ont pas permis une détection précoce des diarrhées de manière efficace, les résultats de sensibilité et de spécificité étant insuffisants (respectivement 74 et 58 %) pour une utilisation pertinente sur le terrain. Pour les études futures, de nouveaux paramètres comme la mesure automatique de la température corporelle ou la localisation des porcelets dans la case par analyse d'images pourraient améliorer les performances de ces méthodes. Early detection of diarrhoea in weaned piglets from individual feed, water and weighing data Detecting diseases early in pig farming is a promising way to help breeders monitor animal health, reduce antibiotic use and treat sick animals in a targeted manner. This study analysed individual water and feed consumption as a function of the live weight of weaned piglets and its relation to diarrhoea. Data were collected from 15 batches of 102 piglets each, using specific automata (i.e. connected feeders, connected drinkers, automatic weighing stations, RFID ear tags), and piglet health status was monitored daily. Analysis used seven machine learning methods. Mean water and feed consumption of healthy pigs did not differ significantly among weight categories, except in week five, due to atypical water consumption by a heavy pig. In addition, mean water consumption did not differ significantly between healthy and sick piglets, either on the day that diarrhoea was observed or two days before. However, mean feed consumption of healthy piglets and those with diarrhoea did differ significantly from day 4-9 post-weaning and even 24 and 48 h before the onset of clinical signs. Nevertheless, the machine-learning methods tested did not provide effective early detection of diarrhoea, due to insufficient sensitivity and specificity of results (74% and 58%, respectively) for field use. In future studies, new parameters such as automatic measurement of body temperature or location of piglets in the pen by image analysis could improve the performance of these methods.

Raw full-fat soybeans of three varieties (Bahia, Isidor and Ecudor) were used at levels ranging from 2.5 to 12.5 % to prepare fattening diets averaging 0.8, 1.5, 2.5, 3.3 and 3.5 trypsin inhibitor units (TIU)/mg in Exp.1, and 0.9, 1.7, 2.2, 2.4, 4.0 and 4.8 TIU/mg in Exp.2. In Exp.3, pigs were fed 0.7 or 2.8 TIU/mg during the growing period and for the finishing period were either fed the same diet or switched to a different diet to assess the back-effect of the initial feed. For Exp.1 and 2, a total of 310 females and barrows were housed in six pens of five pigs each per treatment in Exp.1, and four or six pens of five pigs each per treatment in Exp.2. In Exp.3, 32 barrows were used in individual pens. For all trials, individual faecal scoring was similar among treatments. Average daily feed intake (ADFI) was affected by diets in Exp.2 for the early-growing and growing periods (P < 0.05), as well as average daily gain (ADG) and feed conversion ratio (FCR) for the early-growing period in trial 1, and the early-growing and growing periods in Exp. 2 (P < 0.01). Each TIU resulted in a 32 g decrease in ADG (RSD = 48) and a 0.05 point increase in FCR (RSD = 0.08). For finishing stage, performance did not differ among treatments. Carcass yield was decreased for 3.3 and 3.5 TIU/mg in Exp.1. In Exp.3, the 2.8 TIU feed decreased ADFI and ADG, and increased FCR in the early-growing period but the differences were not significant for the growing period. For finishing period, pigs fed 0.7 then 2.8 TIU/mg diets had lower ADFI and ADG (P < 0.05), while their FCR was higher (P < 0.05). Pigs of both treatments given 2.8 ITU/mg for the finishing period had lower carcass yield (P = 0.08) and higher pancreas weight (P < 0.05). A maximum limit of 2.0 TIU of anti-trypsin factors per mg of feed is proposed for growing and finishing pigs., Quel seuil d'incorporation sans effets des facteurs anti-trypsiques du soja pour l'alimentation du porc en engraissement ? Plusieurs variétés de graines de soja (Bahia, Isidor et Ecudor) sont incorporées crues à des taux allant de 2,5 à 12,5%, pour préparer des aliments d'engraissement contenant respectivement 0,8, 1,5, 2,1, 3,3 et 3,5 unités d'inhibiteur de trypsine (TIU) /mg dans l'essai 1, et 0,9, 1,7, 2,2, 2,4, 4,0 et 4,8 TIU/mg dans l'essai 2. Dans l'essai 3, les animaux reçoivent des aliments à 0,7 ou 2,8 TIU/mg en période de croissance, puis en finition reçoivent les mêmes aliments, ou bien changent d'aliment afin d'évaluer l'arrière-effet de l'aliment précédent. Pour les essais 1 et 2, 310 femelles et mâles castrés sont utilisés à raison de six cases de cinq porcs par traitement dans l'essai 1, puis quatre ou six cases de cinq porcs par traitement dans l'essai 2. Dans l'essai 3, 32 porcs mâles castrés sont utilisés en loge individuelle. Pour tous les essais, les scores individuels de consistance des fèces ne diffèrent pas selon le traitement. La consommation d'aliment (CMJ) est affectée par les aliments lors de l'essai 2 pour les périodes nourrain puis croissance (P < 0,05), ainsi que le gain moyen quotidien (GMQ) et l'indice de consommation (IC) pour la période nourrain dans l'essai 1, et les périodes nourrain et croissance dans l'essai 2 (P < 0,01). Chaque TIU entraine une baisse de 32 g du GMQ (ETR = 48) et une hausse de 0,05 point d'IC (ETR = 0,08). En finition, les performances ne diffèrent pas entre régimes. Le rendement de carcasse est diminué à 3,3 et 3,5 TIU/mg dans l'essai 1. Pour l'essai 3, l'aliment à 2,8 TIU/mg diminue la CMJ et le GMQ, et augmente l'IC en période nourrain mais les différences ne sont pas significatives en croissance. En finition, la CMJ et le GMQ des porcs recevant successivement les régimes à 0,7 puis à 2,8 TIU/mg sont moins élevés (P < 0,05), alors que leur IC est plus élevé (P < 0,05). Les porcs des deux groupes recevant 2,8 TIU/mg en finition ont un rendement carcasse diminué (P = 0,08) et un poids de pancréas plus élevé (P < 0,05). Une teneur limite maximale de 2,0 TIU de facteurs anti-trypsiques par mg d'aliment est proposée pour le porc en engraissement.

A growing body of evidence supports a role for tissue-to-diet 15N and 13C discrimination factors (&Delta, 15N and &Delta, 13C), as biomarkers of metabolic adaptations to nutritional stress, but the underlying mechanisms remain poorly understood. In obese rats fed ad libitum or subjected to gradual caloric restriction (CR), under a maintained protein intake, we measured &Delta, 13C levels in tissue proteins and their constitutive amino acids (AA) and the expression of enzymes involved in the AA metabolism. CR was found to lower protein mass in the intestine, liver, heart and, to a lesser extent, some skeletal muscles. This was accompanied by &Delta, 15N increases in urine and the protein of the liver and plasma, but &Delta, 15N decreases in the proteins of the heart and the skeletal muscles, alongside &Delta, 13C decreases in all tissue proteins. In Lys, &Delta, 15N levels rose in the plasma, intestine, and some muscles, but fell in the heart, while in Ala, and to a lesser extent Glx and Asx, &Delta, 13C levels fell in all these tissues. In the liver, CR was associated with an increase in the expression of genes involved in AA oxidation. During CR, the parallel rises of &Delta, 15N in urine, liver, and plasma proteins reflected an increased AA catabolism occurring at the level of the liver metabolic branch point, while &Delta, 15N decreases in cardiac and skeletal muscle proteins indicated increased protein and AA catabolism in these tissues. Thus, an increased protein and AA catabolism results in opposite &Delta, 15N effects in splanchnic and muscular tissues. In addition, the &Delta, 13C decrease in all tissue proteins, reflects a reduction in carbohydrate (CHO) oxidation and routing towards non-indispensable AA, to achieve fuel economy.

Depuis des décennies, les filières agroalimentaires génèrent des coproduits de première ou de deuxième transformation qui représentent en France un gisement important (12 millions de tonnes de matière sèche), dont plus de la moitié est issue des filières de la trituration (29 %), de la sucrerie (14 %) et de l'amidonnerie-féculerie (13 %). Les trois-quarts de ces ressources sont valorisés en alimentation animale, pour 80 % environ via les aliments composés et 20 % directement en élevage. De ce fait, les coproduits, que les réglementations européenne et française distinguent clairement de la catégorie « déchets », sont des matières premières de l'alimentation animale à part entière et doivent en respecter la réglementation. La disponibilité de ces coproduits peut fortement varier dans le temps avec une saisonnalité marquée pour certaines filières, ou dans l'espace selon la répartition des usines agroalimentaires sur le territoire et la superposition avec les zones d'élevage. Les procédés technologiques générateurs de ces coproduits peuvent différer d'une filière à l'autre. La nature et la composition chimique des coproduits dépendent du procédé mis œuvre qui peut évoluer dans le temps, mais également d'une usine à l'autre au sein d'une même agro-industrie. Leur bonne valorisation en alimentation animale est largement conditionnée par une connaissance précise de la qualité des différentes fractions organiques (parois végétales et protéines, notamment) ou minérales accumulées dans les coproduits, et de l'efficacité de leur utilisation qui peut varier fortement selon l'espèce animale destinataire (ruminants ou monogastriques) et selon les types de process appliqués. Un certain nombre de recommandations alimentaires et sanitaires doivent être appliquées pour garantir une utilisation optimale des coproduits par les animaux sans pénaliser leurs performances zootechniques. Ces coproduits présentent de ce fait une réelle valeur économique qu'il est possible de déterminer, même pour les ruminants, au moyen des outils de formulation à moindre coût par programmation linéaire couramment utilisés chez les monogastriques., For decades, agro-food chains have been producing either first or second transformation byproducts, which represent in France a significant amount of resources (12 million tons of dry matter, Réséda 2007). These byproducts come mainly from the crushing sector (29 %), sugar refinery (14 %) and starch industry (13 %). Most of these resources (75 %) are used in animal feeding, including about 80 % via the compound feed industry and 20 % directly on the farms. Hence, agro-industrial by-products, which are clearly defined as non-waste products by French and European regulations, have become raw materials used in animal feed and must therefore comply with the regulations applicable to such products. The availability of these byproducts can vary considerably over time with a marked seasonality for certain sectors, as well as spatially according to the distribution of agro-food factories on the territory and the overlap with the animal production areas. The technological processes generating these byproducts can differ from one sector to another. Botanical and chemical composition of byproducts depend on the process implemented, which can evolve over time but also from one factory to another within the same agro-industry sector. Making the most of these byproducts in animal feeding is largely conditioned by the precise knowledge of the quality of the various organic (essentially cell walls and proteins) or mineral fractions accumulated in the byproducts, and of their utilization efficiency which can change strongly according to the animal species (ruminants vs monogastrics) and according to the types of processes applied. Some feeding recommendations and sanitary rules must be enforced to ensure an optimal utilization of byproducts by the animals without decreasing their performances. Therefore, these byproducts have a real economic value that can be determined, even for ruminants, using the low-cost linear programming formulation tools commonly used for monogastrics.

National audience; The effect of a calcium (Ca) and phosphorus (P) depletion and repletion strategy was studied in four consecutive feeding phases of 28 days each. In all, 60 castrated male pigs (14±1.6 kg initial BW) received 60% (low (L) diet; depletion) or 100% (control (C) diet; repletion) of their Ca and digestible P requirements according to six feeding sequences (CCCC, CCCL, CLCC, CCLC, LCLC and LLLL; subsequent letters indicate the diet received in phases 1, 2, 3 and 4, respectively). Pigs bone mineral content in whole-body (BMCb) and lumbar vertebrae L2 to L4 (BMCv) was measured in every feeding phase by dual-energy X-ray absorptiometry. Growth performance was slightly (

Solid state fermentation (SSF) is a biotechnological process particularly well adapted to the treatment of vegetable biomass. This technology adjustable to industrial scale, is adapted to current challenges in animal nutrition by developing fermented products in order to improve the quality of raw materials from a nutritional and functional point of view. The work presented in this thesis considers these issues using rapeseed meal from the oil crushing industry.A first screening study highlighted several fungal strains based on their growth performance and protein enrichment (total and digestible) of the substrate. Levels similar to those of soybean meal, the main protein source in animal nutrition, have also been reached. An interesting biological activity was then reported in vitro on immune cells. To date, this way has never been investigated concerning solid state culture. The presence of fungal immunomodulatory compounds as β-glucan confers added value to the fermented product. Recently, there has been growing interest in natural immunomodulators as they represent an alternative to the use of antibiotics for growth promotion in food animal production. SSF process optimization improved the growth performance of the strain A. sojae and helped to determine the best strategy to maintain optimum growth conditions at larger scale in the deep-bed pre-pilot reactor. Complications related to the fine particle size of the rapeseed meal and the changes in microbiological quality during fermentation under non-sterile conditions were also identified and partially controlled by the process., La fermentation en milieu solide (FMS) est un procédé biotechnologique particulièrement bien adapté au traitement de la biomasse végétale. Cette technologie, extrapolable à l’échelle industrielle, peut répondre aux besoins actuels du marché de l’alimentation animale en développant des produits fermentés visant à améliorer les qualités des matières premières d’un point de vue nutritionnel et fonctionnel. Les travaux de recherche présentés dans cette thèse développent ces aspects à partir du tourteau de colza issu du procédé de trituration des graines.Un premier criblage a mis en évidence le potentiel de certaines souches fongiques en prenant en compte les performances de croissance et leur capacité à enrichir le tourteau en protéines totales et digestibles. Des teneurs comparables à celles du tourteau de soja, principale source de protéine en nutrition animale, ont d’ailleurs été atteintes. Une activité biologique d’intérêt a ensuite été démontrée in vitro sur cellules immunitaires. Cette voie, inexplorée jusqu’à présent à partir de culture en milieu solide, confère une valeur ajoutée au produit fermenté via un apport en composés immunomodulateurs naturels d’origine fongique comme les β-glucanes. Ces derniers suscitent un intérêt croissant car ils représentent une alternative à l’utilisation des antibiotiques comme facteur de croissance. L’étude consacrée à la phase d’optimisation du procédé FMS a permis d’accroître les performances de croissance de la souche A. sojae et de définir une stratégie visant à maintenir les conditions optimales de croissance en réacteur pré-pilote à couche profonde. Des complications liées à la granulométrie très fine du tourteau de colza et à la qualité microbiologique qui évolue en cours de fermentation dans des conditions non stériles ont pu être identifiées mais le procédé mis en place a alors permis de les maîtriser en partie.

Knowledge of the diachronic occupation of the Bas-Languedoc region is evidence of the attractive character of the Hérault terraces as of the recent Neolithic period. This includes the results of the first surveys, launched at the end of the 1970s, as well as those of the numerous preventive excavations following the increasing urbanisation of the valley and the overhaul of its communication networks. That is why the central Hérault archaeology is one of the most active in the region. Unknown until then, the Causses site was identified and then excavated during the interventions motivated by the A750 motorway construction project. The study was carried out during the winter of 2003, as part of a vast operation (known as the Lagarel operation), whose footprint was extended to three other sites located in the immediate vicinity. The archaeological data (that will be called “ conventional”), in other words those deduced from the chronology and architecture of the establishment – not to mention the material culture elements – are struggling to properly characterize the occupation. For this reason, an important place has been allotted to the archaeozoological study, with a view to broadening the interpretative field. From the restitution of the site itself to a regional perspective, the aim was to understand these sites dynamics from a food and, more generally, an agricultural point of view., Les connaissances concernant l’occupation diachronique du Bas-Languedoc font foi du caractère attractif des terrasses de l’Hérault à partir du Néolithique récent. Participent de ce constat les résultats des premières enquêtes, engagées à la fin des années 1970, tout comme ceux des nombreuses fouilles préventives consécutives à l’urbanisation grandissante de la vallée et à la refonte de ses réseaux de communication. L’archéologie du centre-Hérault est en cela l’une des plus actives de la région (1). Jusqu’alors inconnu, le gisement des Causses a été identifié, puis fouillé, à l’occasion des interventions motivées par le projet de construction de l’autoroute A750 (Raux 2004 ; Ginouvez et al 2007). L’étude a été réalisée durant l’hiver 2003 dans le cadre d’une vaste opération (dite du Lagarel) dont l’emprise a été étendue à trois autres sites localisés à proximité immédiate (2) (fig. 1). Les données archéologiques que nous qualifierons de «conventionnelles » , autrement dit, celles déduites de la chronologie et de l’architecture de l’établissement – sans oublier les éléments de la culture matérielle – peinent à caractériser correctement l’occupation. Pour cette raison, une place importante a été accordée à l’étude archéozoologique, dans l’intention d’élargir le champ interprétatif. De la restitution du site en lui-même à une mise en perspective régionale, l’objet était de saisir dans quelles dynamiques s’inscrivent les lieux d’un point de vue alimentaire, et plus généralement agricole., Los datos acerca de la ocupación diacrónica del Bas-Languedoc demuestran el carácter atractivo de las terrazas del Hérault desde el Neolítico reciente. Los resultados de las primeras investigaciones, iniciadas a finales de 1970, concuerdan con los de las numerosas excavaciones preventivas ocasionadas por la creciente urbanización del valle y de la remodelación de sus vías de comunicación. La arqueología del centro del Hérault es una de las más activas de la región. Desconocido hasta ese momento, el yacimiento de Causses fue identificado y luego excavado durante las intervenciones derivadas del proyecto de construcción de la autopista A750 (Raux 2004 ; Ginouvez et al 2007). El estudio se llevó a cabo durante el invierno de 2003 como parte de una vasta operación (conocida como «operación Lagarel » ), que acabó extendiéndose a otros tres yacimientos ubicados en las inmediaciones. Los datos arqueológicos que llamaremos «convencionales » , es decir, los deducidos de la cronología y la arquitectura del sitio -sin olvidar los elementos de la cultura material-, apenas permiten caracterizar correctamente la ocupación. Por este motivo, y con la intención de ampliar el campo interpretativo, se ha dado importancia al estudio arqueozoológico. Desde la restitución del yacimiento en sí, hasta su estudio desde una perspectiva regional, el objetivo era comprender las dinámicas en las cuales se inscribían estos lugares desde el punto de vista alimentario y, de manera más general, desde el punto de vista agrícola., Ginouvez Olivier, Forest Vianney, Chabal Lucie, Compan Michel, Figueiral Isabelle, Jung Cécile. Le site des Causses à Saint-André de Sangonis (VIe siècle) et la place alimentaire des animaux dans la moyenne vallée de l’Hérault durant le haut Moyen Âge. In: Archéologie du Midi médiéval. Tome 35, 2017. pp. 3-39.

National audience; Since the 1960s, the improvement of animal feed rations has greatly contributed to the increase in productivity on livestock farms. When grazed forage is a significant component of animal feed rations, especially in regions where the climate varies considerably between seasons, this improvement involves the management of complex balances, in real time, between forage availability and the animals’ needs. Moreover, the livestock farmer must take the various environmental limitations, regulations linked to the preservation of the environment, and injunctions from the sectors that market his products into account in his decisions. The medium mountains of Auvergne where grassland constitutes the feed base for the herds throughout the seasons are a good case study to address these questions. Grasslands here imply specific challenges, and to understand the different ways of managing grassland feed requires an in-depth look at the approaches and practices of livestock farmers. This article focuses on two specific and contrasted grazing systems observed in the Livradois-Forez region: bovines always inside or always in the same meadow. Between zero grazing and continuous grazing, it is shown, using an agronomic analysis framework, how the degree of importance attributed to grazing reflects livestock farmers’ strategies that are not limited to feeding the animals alone, but depend on natural, historical and human factors as well. Thus, large dairy farms have chosen zero grazing to more easily manage their fragmented parcels, to preserve their forage resource and to have a stable and high-quality feed ration. Another livestock farmer has chosen continuous grazing to free up time for a more lucrative crop production unit. These different realities question agricultural models and ways in which to help livestock farmers, which must take account of the fact that the diversity of systems is perhaps a condition for maintaining livestock breeding in these middle mountain regions.; Pâturer : regards agronomiques et pratiques d’éleveurs. La conduite du pâturage comme révélateur des stratégies d’éleveurs dans le Livradois-Forez. Depuis les années soixante, l’amélioration des rations alimentaires des animaux a fortement contribué aux accroissements de productivité dans les élevages. Lorsque les fourrages pâturés sont une composante significative des rations, notamment dans les régions où le climat varie fortement entre les saisons, cette amélioration implique de gérer des équilibres complexes et en « temps réel » entre les disponibilités en fourrage et les besoins des animaux. De plus, l’éleveur doit intégrer dans ses décisions des contraintes du milieu variées, des éléments réglementaires liés à la préservation de l’environnement et des injonctions venant des filières commercialisant ses produits. Les moyennes montagnes d’Auvergne, où les prairies sont la base de l’alimentation des troupeaux au long des saisons, sont un bon support pour s’intéresser à ces questions. Le pâturage est ici porteur d’enjeux particuliers, et comprendre les modes de gestion de l’alimentation au pâturage nécessite un regard appuyé sur les conceptions et les pratiques des agriculteurs. Cet article s’intéresse à deux modalités de pâturage particulières et contrastées, observées dans une commune du Livradois-Forez : des bovins toujours dedans ou toujours dans le même pré. Entre zéro pâturage et pâturage continu, il montre, à l’aide du cadre d’analyse agronomique, en quoi la place accordée au pâturage reflète des stratégies d’éleveurs qui ne se limitent pas à la seule finalité d’alimenter des animaux, et dépendent à la fois de facteurs naturels, historiques et humains. Ainsi de grandes exploitations laitières ont choisi le zéro pâturage pour gérer plus facilement leur parcellaire morcelé, préserver la ressource fourragère et avoir une ration stable et de qualité. Un autre éleveur a choisi le pâturage continu pour se libérer du temps pour un atelier végétal rémunérateur. Ces réalités interrogent les modèles agricoles et les modes d’accompagnement des éleveurs, qui doivent prendre en compte que la diversité des systèmes est peut être une condition du maintien de l’élevage dans ces zones de moyenne montagne.

Pâturer : regards agronomiques et pratiques d’éleveurs. La conduite du pâturage comme révélateur des stratégies d’éleveurs dans le Livradois-Forez. Depuis les années soixante, l’amélioration des rations alimentaires des animaux a fortement contribué aux accroissements de productivité dans les élevages. Lorsque les fourrages pâturés sont une composante significative des rations, notamment dans les régions où le climat varie fortement entre les saisons, cette amélioration implique de gérer des équilibres complexes et en « temps réel » entre les disponibilités en fourrage et les besoins des animaux. De plus, l’éleveur doit intégrer dans ses décisions des contraintes du milieu variées, des éléments réglementaires liés à la préservation de l’environnement et des injonctions venant des filières commercialisant ses produits. Les moyennes montagnes d’Auvergne, où les prairies sont la base de l’alimentation des troupeaux au long des saisons, sont un bon support pour s’intéresser à ces questions. Le pâturage est ici porteur d’enjeux particuliers, et comprendre les modes de gestion de l’alimentation au pâturage nécessite un regard appuyé sur les conceptions et les pratiques des agriculteurs. Cet article s’intéresse à deux modalités de pâturage particulières et contrastées, observées dans une commune du Livradois-Forez : des bovins toujours dedans ou toujours dans le même pré. Entre zéro pâturage et pâturage continu, il montre, à l’aide du cadre d’analyse agronomique, en quoi la place accordée au pâturage reflète des stratégies d’éleveurs qui ne se limitent pas à la seule finalité d’alimenter des animaux, et dépendent à la fois de facteurs naturels, historiques et humains. Ainsi de grandes exploitations laitières ont choisi le zéro pâturage pour gérer plus facilement leur parcellaire morcelé, préserver la ressource fourragère et avoir une ration stable et de qualité. Un autre éleveur a choisi le pâturage continu pour se libérer du temps pour un atelier végétal rémunérateur. Ces réalités interrogent les modèles agricoles et les modes d’accompagnement des éleveurs, qui doivent prendre en compte que la diversité des systèmes est peut être une condition du maintien de l’élevage dans ces zones de moyenne montagne., Since the 1960s, the improvement of animal feed rations has greatly contributed to the increase in productivity on livestock farms. When grazed forage is a significant component of animal feed rations, especially in regions where the climate varies considerably between seasons, this improvement involves the management of complex balances, in real time, between forage availability and the animals’ needs. Moreover, the livestock farmer must take the various environmental limitations, regulations linked to the preservation of the environment, and injunctions from the sectors that market his products into account in his decisions. The medium mountains of Auvergne where grassland constitutes the feed base for the herds throughout the seasons are a good case study to address these questions. Grasslands here imply specific challenges, and to understand the different ways of managing grassland feed requires an in-depth look at the approaches and practices of livestock farmers. This article focuses on two specific and contrasted grazing systems observed in the Livradois-Forez region: bovines always inside or always in the same meadow. Between zero grazing and continuous grazing, it is shown, using an agronomic analysis framework, how the degree of importance attributed to grazing reflects livestock farmers’ strategies that are not limited to feeding the animals alone, but depend on natural, historical and human factors as well. Thus, large dairy farms have chosen zero grazing to more easily manage their fragmented parcels, to preserve their forage resource and to have a stable and high-quality feed ration. Another livestock farmer has chosen continuous grazing to free up time for a more lucrative crop production unit. These different realities question agricultural models and ways in which to help livestock farmers, which must take account of the fact that the diversity of systems is perhaps a condition for maintaining livestock breeding in these middle mountain regions.

Animal diseases, foodborne pathogens and foodborne diseases have enormous impacts upon the health and livelihoods of producers and consumers in developing and in-transition countries. Unfortunately, the capacity for effective surveillance of infectious disease threats is often limited in these countries, leading to chronic under-reporting. This further contributes towards underestimating the effects of these diseases and an inability to implement effective control measures. However, innovative communications and diagnostic tools, as well as new analytical approaches and close cooperation within and between the animal and human health sectors, can be used to improve the coverage, quality and speed of reporting, as well as to generate more comprehensive estimates of the disease burden. These approaches can help to tackle endemic diseases and build essential surveillance capacities to address changing disease threats in the future.

Farmer's lung (FL) is the most common type of hypersensitivity pneumonitis (HP), with an estimated prevalence of between 0.5 and 1.5% in dairy farmers. In chronic FL, fibrotic sequelae are widely described in the literature although our experience and occasional epidemiological studies emphasize an increased risk of developing emphysema in these patients.We report a case of FL in a 37-year-old patient with typical clinical features (exertional dyspnoea, lymphocytic alveolitis and computed tomography appearances) together with proven allergen exposure. This patient developed early pulmonary emphysema probably due to intermittent massive exposure to antigens and to bacterial and fungal micro-organisms.The current classification of HP differentiates acute, subacute and chronic forms but does not take account of the role of the mode of exposure and the evolution of the disease. The prognosis and evolution of HP seem to be dependent on the type and pattern of exposure. A new classification with two clusters has been suggested: in type 1, massive and intermittent exposure, as in FL, may lead to emphysema with chronic airflow obstruction and, in type 2, chronic exposure to a low level, as in bird fanciers, may lead to fibrosis with a restrictive pattern.

We present a modeling effort which is part of the PSDR Grand-Ouest reseach project "Competitiveness, Localisation, Public Policies" (CLAP). The models aims at spatializing both the local supply of cereals, oilseeds and protein crops which enter the composition of animal feed, and the local demand for animal feed. The underlying objective is to endogenize the "agricultural" part of the Feedsim model which up to now concentrates on the "industrial" part of the supply chain.; Le modèle économique en cours de mise au point constitue l’une des actions de recherche du projet Compétitivité, Localisation, Action Publique (CLAP) du programme PSDR Grand Ouest. Il vise à représenter de façon spatialisée, d’une part, l’offre locale des exploitations de Grande Culture en céréales et oléo-protéagineux, principales matières premières agricoles entrant dans la composition des aliments du bétail, et, d’autre part, la demande locale en aliments du bétail des exploitations d’élevage. Ceci permettra de rendre endogène le volet « agricole » du modèle Feedsim, actuellement centré sur le volet « industriel » de la filière, utilisé par les professionnels et les institutions publiques du Grand Ouest comme outil d’aide à la décision en matière de développement économique régional ou encore de choix d’infrastructures de transport.

The goal of this work was to study the possible use of the food cubes in bovines' and the small ruminants' feeding in Bamako district and to evaluate its potential effects on these animals' libido.To undertake this study, a transversal investigation among 384 emboucheurs and emboucheurs stockbreeders were carried out from 22 to 24 April, 2007 in 11 cattle markets in the District of Bamako. The study included 20 Moor rams aged 2 to 3 years old, divided into 4 batches of 5 heads each; 15 Moor ewes aged 2 to 3 years old were synchronized regularly and put in heat for measurements of the libido. The sheep were fed with food made up with fan of Niébé and cotton oil cake, with respectively 0 cubes jumbo for the 1st batch (control group), 2 cubes for the 2nd batch and 4 cubes for 3rd and 6 cubes for the 4th batch (the study groups).Finding showed that the principal ration used by the emboucheurs was the combination of straw of bush and cattle food provided by HUICOMA factories (ABH), 98,70%. The investigations revealed also that only 0,50% of the emboucheurs used the cubes Jumbo or Maggi chicken to accelerate the weight increase of their animals. Regarding the measurement of the libido, findings showed that the addition of food cubes in rams of batches II, III and IV feeding, reduced in a remarkable way time that these animals put before jumping in the presence of a ewe in heat. Regarding dimensions of the scrotum, testicles of the rams, the addition of the food cubes does have any influence.The study enabled us to affirm that the addition of food cubes in rams feeding improved considerably the libido of these animals and any impact on their health have been observed.

L’importance des exploitations d’élevage dans l’agriculture bretonne conduit à l’implantation d’un nombre élevé d’industries de l’alimentation animale dans la région. Les flux en aliments du bétail sont ainsi une question clé pour ce secteur. Dans ce papier, nous présentons un modèle basé sur la programmation linéaire et calibré grâce à la technique de la programmation mathématique positive, visant à étudier la localisation de l’offre et de la demande en aliment du bétail. Les productions agricoles actuellement incluses dans le modèle sont les grandes cultures et la viande de porc. Nous décrivons le modèle et expliquons la stratégie de calibration retenue en fonction des données disponibles. L’utilité du modèle est illustré à partir de quelques simulations., The high proportion of livestock farms in the agriculture in Brittany results in many animal feed factories established in this area. Thereby, the animal feed flows evolution is a major issue for this sector. This paper presents a farm model based on a linear programming approach using a Positive Mathematical Programming calibration procedure which aims at studying the localisation of the supply and demand of animal feed. Agricultural productions modelled thus far are limited to cereals and pork meat in Brittany. We describe the proposed model and explain how it as been calibrated from the available data. Some simple simulations are also presented to illustrate how the model fulfils or not expectations.

Why has the French food safety agency been particularly mobilized on zoonoses like bovine spongiform encephalopathy ("mad cow disease") or highly pathogenic avian influenza ("bird flu") ? Because sanitary crisis make explicit an ambivalent relationship between humans and animals (animals being perceived alternatively as providers of goods and as bearers of threats), and to the circulation of life in general (the contaminated blood crises being due to the rapprochement of blood giving and blood receiving). The sociology of risks needs therefore to reintegrate the idea of an intention of the risk bearer (risk with enemy), and the sociology of alimentation needs to reintegrate the analysis of the conditions of production. Mad cow disease is the paradigmatic food safety crisis because it brings together the poles of production and consumption, of animals and humans. It therefore belongs to anthropology.

Fish protein (FP) effect compared to casein (CAS) was studied on blood pressure (BP) evolution and glycemia in part, and on plasma lipid, angiotensine II and aldosterone concentrations and urinary aldosterone on the other hand, in SHR and in SHR with streptozotocin-induced diabetes (SHR-STZ). Two groups of rats (6 SHR and 6 SHR-STZ) were fed for 2 months diet containing 20% CAS or 20% FP. One month before sacrifice, diabetes was induced into one group of rats by a single intraperitonealy injection of streptozotocin (STZ). The results showed that FP diminished blood pressure (-9%) in SHR, compared with CAS. In contrast, FP enhanced significantly blood pressure in SHR-STZ vs SHR (p0.01). There was no effect on glycemia with fish protein. FP compared to CAS involved a diminution (-41%) and (-17%) of total cholesterol and (-26%) and (-9%) of phospholipids in SHR and SHR-STZ, respectively. Moreover, a decrease of triacylglycerols (-21%) was noted in SHR-STZ with FP vs CAS. In SHR, plasma aldosterone and angiotensine II concentrations were reduced (-62%) and (-64%) and urinary aldosterone amounts were enhanced with FP compared to CAS (p0.05). In SHR-STZ group, aldosterone value was fivefold lower in plasma and twofold higher in urine with FP compared to CAS. A significant enhancement of urinary aldosterone was noted in SHR-STZ vs SHR whatever diet-consumed. In conclusion, FP has a beneficial effect on blood pressure by modulating the hypertension markers i.e. plasma total cholesterol, angiotensine II and aldosterone, in SHR group, and on total cholesterol and triglycerids in SHR-STZ. FP reduces plasma aldosterone by its enhanced urinary excretion. It is necessary to specify the action mode of FP in order to propose it as nutritional complement in the degenerative diseases such as hypertension and diabetes.

Transmissible subacute spongiform encephalopathies have been known for some times in man and in animals, but were considered of minor importance up to the development of the mad cow crisis. Bovine spongiform encephalopathy raises questions about nowadays farming and brings up the issue of cannibalism as a whole and imposed upon an herbivore. Even if the word cannibalism may seem excessive in the case of cattle, it is however true that BSE spreads from cow to cow through their feeding with meat and bone meal contaminated with infected bovine material. More generally this points out the problem of cannibalism among animal species.

Recurrent or chronic urticaria seems to be a food allergy in thoroughbred race-horses during the training season. In resistant cases, allergologic techniques will be required to determine aetiology. Intradermal skin tests with fresh allergenic food may cause syndromic reaction as urticaria and akin to enteritis in some horses. In most cases, an elimination of the allergen responsible brings a rapid and long-lasting result. Study about 22 cases.

When medical history and clinical examination for a recurrent or chronic cough reveal the presence of perennial allergy, the practitioner would be advised to look for mites present in the horse's environment. He can propose this service to his clients.

The identification of variant Creutzfeldt-Jakob disease (vCJD) in human strongly reinforced the perception of risks associated with the infectious agent involved in Bovine Spongiform Encephalopathy (BSE). The development of rapid tests for the diagnosis of BSE by the detection of the abnormal prion protein allowed a huge increase in surveillance of the cattle disease. This first revealed a higher prevalence of the infection than previously believed. However, food safety measures, mainly based on the ban of the use of meat and bone meal in ruminants and the elimination of specified risk materials from the food chain, already allowed significant progress in the control of the cattle disease, especially in the United Kingdom. Nevertheless, the diagnosis can still not be obtained in the live animal, while the disease only appears following a several years incubation period. Another major issue is the identification of the BSE agent when it has been transmitted to another species. This question not only arises in veterinary medicine, with the major question of a possible infection of small ruminants by the BSE agent, but also in human in which the existence of other forms of the disease linked to the BSE agent but possibly differing from Creutzfeldt-Jakob disease cannot be excluded.

The copper and zinc contents of 25 rations for adult horses were evaluated. The total amount of copper and zinc daily ingested was obtained by adding the amount of each element contained and added of the commercial feed to the amount contained in ingested hay and oats. The total amount of copper and zinc ingested daily was compared with the official recommendations for the maintenance of an adult horse of 550 kg. The results show that a traditional ration oats/hay does not contain a sufficient amount of copper and zinc in order to cover their respective requirements. Furthermore, many rations which include commercial feed also do not cover the requirements of these two elements. The importance of these observations is discussed in the light of the eventual need to complete the rations.

Diagnosis of allergy diseases is at first linked to a detailed history, in which professional activities as well as the environment take an important place. Fishing activity as well as aquarium-related activities may be the origin of a symptomatology which is, often IgE-mediated, respiratory and skin localised: the responsible agents are most often insects in their larval form, crustaceans and worms.

Mycotoxins are toxic products secreted by microscopic fungi. They can contaminate products of vegetal origin consumed by humans and cattle, therefore secondary by humans. The most important mycotoxins are aflatoxins, hepatotoxic and hepatocarcinogenic, and ochratoxins, nephrotoxic and nephrocarcinogenic. The maximal authorized limits of aflatoxin contents in human and animal food-stuffs are very low (few microg/kg or fractions of microg/kg).

In 1999, a food crisis broke out in Belgium as a result of the accidental contamination of animal feed by PCBs (polychlorobiphenyls) and dioxins (mainly furans). The analysis of the database from the PCB food monitoring program implemented after the discovery of incident confirms that the contamination has been very limited, both in time (peak at the end of January) and in the food chain (affecting less than 0.5% of the farms in the whole country). The extreme scenario of a doubling of the PCB and dioxin body burden as envisaged in "Nature" (401: 231-232, 1999) could have been conceivable only in the case of farmers who would have consumed their own products. But even in such an extreme case, this would mean going back to the levels of PCB and dioxin body burden of subjects living in the 1980s or of those regularly eating contaminated seafood.

Three feeding methods were compared in 36 4- to 6-year-old Franche-Montagne horses during the military school of St-Luzisteig (GR) of Spring 1992. The horses were separated into 3 groups: a group with the traditional oats-hay ration (OH), a group with a pelleted feed and hay ration (PFH), and a group with the complete diet (CD). Feed analyses were performed and food consumption, eating behavior and digestibility were studied. The horses received their daily amount of feed in 3 portions covering the requirements for a medium work: OH = 8 kg hay and 3 kg oats, PFH = 8 kg hay and 3 kg pelleted feed and CD = 10 kg of the complete diet. For the 3 rations, the amount of digestible crude protein for horses was higher than the reference value for the requirement of a 600 kg horse with a medium work. In the 3 diets, the calcium content was higher than the required 32 g per day (g/d). Not enough sodium (OH: 1.2 g/d; PFH: 7.3 g/d; CD: 9.6 g/d) and too much potassium (OH: 140.3 g/d; PFH 153.0 g/d; CD: 167.5 g/d) were present in the diets, both without consequences for the blood parameters. In 3 meals of 60 minutes, the horses of the group OH, PFH and CD ingested 82%, 89% and 92%, respectively, of the daily ration. The complete diet was ingested more quickly than the hay. The number of mastications per minute was smaller for the complete diet than for the hay. Ingestion times were similar for oats and pelleted feed. However, the number of mastications per minute was smaller for the pelleted feed. The digestibility of nutrients was not influenced by the method of feeding. In conclusion, these results demonstrate that the 3 types of ration studied here are adequate for the swiss army horses if sodium is added to the diet. However, despite the fact that both PFH and CD correct excessive supply or deficiencies of nutrients and despite the fact that these two feeding methods offer nutrients in amounts that are closer to the requirements of the horse, the method PFH was introduced in 1994.

Fish communities from geomorphologically different mangrove forests showed distinct trophic structures. A mangrove area located near fringing reefs (Bouraké) was dominated by large invertebrate (2 mm) feeders (40.7% of total wet weight of the fish fauna) and herbivores (26.7%) whilst an estuarine mangrove (Ouenghi) was characterized by detritus feeders (28.2%), piscivorous (18.2%) and large invertebrate feeders (17.9%). In spite of these differences in trophic structure, similar food webs occurred in both areas, whereas the intensity of fluxes between trophic compartments was different. Resident species were usually at the base of the trophic structure. This component of the fish fauna used available sources of energy, such as microalgae in Bouraké or detritus and phytoplankton in Ouenghi. In contrast, transient species were high level predators, mainly piscivorous and large invertebrate feeders. These species actively contributed to net exports of energy from mangrove areas to nearby coastal habitats. Food webs and energy fluxes associated with trophic migration of fishes were particularly important in non-estuarine mangrove forests because of hydrologic conditions (salinity and turbidity) which were more suitable to the invasion of numerous marine foraging species (carangids, lutjanids, sphyraenids).

Chronic urticaria in otherwise healthy sport horses, generally has an origin in a food allergy, accompanied by a facultative latent enteritis. Etiological diagnosis may be made by skin tests that permit a following targeted avoidance.

In dual outflow continuous fermenters on a 75:25 hay/barley diet, feed degradation and protein synthesis by mixed rumen microbes were tested in relation to the concentrations of HPO4(2-), HCO3- and Cl- and Na+/K+ ratio in artificial saliva, by applying a 16-run Franquart design, and by fitting second-order polynomial models. The HPO4(2-), HCO3-, Cl- concentrations and Na+/K+ ratio ranged from 0.1 to 4 g.L-1, from 0.5 to 7 g.L-1, from 0.1 to 0.5 g.L-1 and from 0.5 to 15 g.g-1, respectively. Buffer salts, particularly HPO4(2-), were the major factors while Cl- concentration had negligible effects on microbial metabolism. Maximal neutral detergent fibre, acid detergent fibre and organic matter degradabilities occurred at intermediate values of HPO4(2-) and HCO3- concentrations. The outflow of microbial protein and the efficiency of microbial protein synthesis, which varied from 26.2 to 37.1 g.N.kg-1 of organic matter truly degraded, reached minima at the centre of the experimental domain.

Ruminal nitrogen degradation and intestinal digestibility (ID) of the undegraded nitrogen of three sunflower meals were determined on three wethers fitted with rumen cannulae and T-type duodenal cannulae using nylon bags. Meals were obtained from semi-dehulled seeds by conventional hexane extraction (samples SD1 and SD2) or from whole seeds by a discontinuous procedure of pressing and hexane extraction (sample W), which causes a superior thermal effect. Therefore, effective degradability of nitrogen for the W sample (0.537) was lower (P < 0.001) than for conventional meals. Between the latter, SD2 had a lower value (P = 0.019) than SD1 (0.776 and 0.812, respectively). ID decreased in all meals (P < 0.001) as the ruminal incubation time (t) increased. This evolution could be described accurately by an exponential curve as ID = s + he(-kit). A method is proposed for estimating the proportion of undegraded ruminal nitrogen digested in the intestines (Di) from 1) the above equation, 2) the undegradable (r) and the insoluble and potentially degradable (b) nitrogen contents of the feed and the degradation rate of the last fraction (k(d)), and 3) the rumen outflow rate of particles (k(p)). The Di value is shown to be: [equation: see text] The percentages of nitrogen from digested feed in the intestines obtained with this method were 15.1, 17.2 and 39.0 for SD1, SD2 and W, respectively. Resulting effective ID values of undegraded nitrogen were 0.804, 0.767 and 0.844. Undigested nitrogen after ruminal and intestinal incubations decreased in linear and quadratic form in all meals as ruminal incubation time increased.

Ochratoxin A is a mycotoxin: a dihydroisocoumarin derivative linked to L. beta phenylalanine. Ochratoxin A is produced by a number of Aspergillus and Penicillium species. This mycotoxin is a carcinogenic, teratogenic, mutagenic and immunosuppressive substance. Ochratoxin A is a common contaminant found in a variety of foods for human nutrition as well as animal feeds. The aim of this study is to discuss nephrotoxic properties of this mycotoxin in humans. Nephrotoxicity has been reported in many animals after exposure to ochratoxin A. Porcine nephropathy due to this mycotoxin is a well known disease characterized by impairment of proximal renal function. Renal damage is also confined to the proximal tubule in other animal species. A good correlation is found between renal function abnormalities and the location of the lesions along the nephron. Of particular interest is the presence of nuclear abnormalities of the epithelial cells with pyknosis, karyorrhexis and karyomegaly. The question is to know if ochratoxin is nephrotoxic in humans. Acute nephrotoxicity seems to be very rare and we found only one case report suggesting such a possibility. We observed the occurrence of chronic renal failure in two patients with a possible responsibility of a chronic ochratoxin A intoxication. Clinical and histologic findings in these two patients were quite similar to those described in several cases of karyomegalic interstitial nephritis. Striking similarities between the changes in renal structure and function seen in ochratoxin A-induced experimental nephropathies and in Balkan endemic nephropathy suggest a common etiologic agent. This mycotoxin could be also responsible for interstitial nephropathies in North Africa.

International audience; A prospective epidemiological survey was conducted in dairy herds in Brittany (France), concerning 139 herd-years. The data were divided into ten 14 herd-year groups (deciles) and three of these were compared using discrimination by barycentric analysis to study herd late gestation and early lactation variables associated with the annual incidence of herd clinical mastitis in the first 60 days of gestation (CMAI). The first decile included herd-years with low CMAI (o to 4.6%), the second decile, herd-years with medium CMAI (11.6 to 14.3%) and the last decile, herd-years with high CMAI (26.3 to 45.5%). Herd data included diet components, milk yield and reproduction parameters, clinical diseases, body condition score, body dirtiness score and circulating biochemical and hematological markers. The high CMAI group had the following characteristics: 1) lower percentages of dried cows supplemented with vitamins 'ADE'; 2) higher levels of plasma ceruloplasmin and higher gamma glutamyl transferase activities (GGT) in the late gestation period; 3) higher percentages of winter calvings (December, January, February). Clinical mastitis risk could be controlled by supplementations with vitamins A, D and E in the late gestation period, because of the potential relationship between oxidative stress and mastitis. Higher GGT activities would be associated with Fasciolasis via common climatic risk factors (rainfall, humidity) for both mastitis and liver flukes. Winter calving and clinical mastitis would be associated with unfavourable hygiene conditions and stress at calving related to high animal density and bad weather conditions. Ceruloplasmin could be a specific predictor for mastitis risk through nutritional, immune and genetic interrelated factors.

The objective of this study was to determine the effect of two probiotics, Saccharomyces cerevisiae (SC) and Aspergillus oryzae (AO), without their culture medium, on the digestion of plant cell wall components in sheep that had been successively defaunated and refaunated. Six sheep fitted with large rumen cannulae were used to study 1) defaunated sheep with no probiotic, 2) defaunated sheep with SC or AO, 3) refaunated sheep with no probiotic, 4) refaunated sheep with SC or AO. The apparent digestibility of the plant cell walls was not altered (P0.05) by the probiotics in defaunated sheep but was increased (P0.05) with SC (+16%) in refaunated sheep. Simultaneously, SC stimulated the growth of the protozoal population in the rumen. As noted in most previous experiments, the positive effect of the presence of protozoa on plant cell wall digestion (P0.001) was confirmed here. The effect (P0.05) of SC or AO on in situ ADF digestion was either not significant or negative in defaunated rumens, whereas it became positive in refaunated rumen after a residence time of 12 h. The improvement of in situ ADF digestion due to the presence of protozoa was significant (P0.05 for NDF; P0.001 for ADF). However, we could not determine whether this was a direct effect of protozoa or an indirect effect operating via bacteria. The limits of the nylon bag technique for evaluating the microbial activity are discussed in relation to the ability of protozoa to enter and grow in the bags, and the pH regulation inside the bags. The pH values below 5.5 noted inside the bags can significantly alter the bacterial and protozoal populations and limit the validity of the technique. SC increased (P0.05) the specific activity of CMCase and xylanase of the solid-adherent bacteria (SAB) isolated from the rumen digesta of refaunated sheep. Stimulation of both the bacterial activity and protozoa numbers could explain the positive effect of SC on cell wall digestion in the rumen since the modelling of marker excretion in faeces showed that the ruminal mean retention time of hay measured from the model of Danhoa et al. was not modified (P0.05) by either refaunation or the presence of probiotics. AO increased (P0.05) the total retention time of the solid particles in the whole digestive tract and increased the ruminal liquid volume in the refaunated animals but it had no effect on the protozoa population or on the polysaccharidase activity of the SAB, which could explain the absence of effect of AO on the total digestibility of plant cell walls. Both probiotics decreased the liquid turnover in defaunated rumens (P0.05) but neither had any effect (P0.05) on this parameter after refaunation. The improvement of plant cell wall degradation in the whole digestive tract is probably due to a stimulation of digestion at the rumen level as indicated by the higher activity of the SAB in rumen digesta and the growth of protozoa.

Poultry products contaminated with pathogenic strains of Newcastle disease virus are a source of virus transmission to susceptible poultry flocks. The probability of contamination varies according to the type of product. Research conducted by various laboratories in Europe has shown that pathogenic virus can be isolated from the carcasses of chickens, whether vaccinated or not, during a brief period after experimental infection. Eggs laid by hens infected with Newcastle disease virus present a very low risk. Furthermore, feathers, bones, blood and offal present potential risks if they are incorporated in poultry feed. Finally, poultry droppings used as a fertiliser can present a major risk of infection in certain circumstances.

Collagen can be preserved during tens of thousands of years in bones and teeth under favorable conditions. Natural isotopic abundances in carbon (13C/12C) and in nitrogen (15N/14N) of ancient bone and tooth collagen correspond to those recorded during the biogenic synthesis and have not been significantly altered during fossilization. These isotopic abundances are linked to those of the proteic fraction of animal and human diets, and to physiological conditions. Three kinds of applications are made possible through these natural isotopic signatures: determination of subsistence strategies in ancient human populations, determination of the diet of extinct species and the analysis of past environmental changes.

Ruminal starch degradation of untreated and formaldehyde-treated wheat and maize was measured in situ (trial 1) and in vitro (trial 2). The in situ starch degradability was higher for wheat than for maize (82.1 vs 52.3%), for untreated cereals than for cereals treated with 1% formaldehyde (77.3 vs 67.0%) and for cereals treated with 1% formaldehyde than those treated with 5% formaldehyde (67.0 vs 57.2%). The in vitro results were similar. The treatment of cereals by formaldehyde decreased starch degradability more for wheat than for maize, suggesting that the treatment was more efficient when cereal starch and/or nitrogen was highly degradable. Formadehyde treatment of wheat was more effective at decreasing the rate of wheat protein degradability than starch degradability. The difference of response to treatment between the two cereals may be due to differences in properties of the protein matrix of these two cereals.

Two adult sheep (75 kg live weight) fitted with rumen cannulas were defaunated by the emptying method during the first period of the experiment. They were inoculated with the genus Isotricha alone during the second period, and with a mixed ciliate population (Entodinium, Eudiplodinium, Epidinium) during the third. They were fed a diet of grass hay (840 g) and pelleted maize grains (360 g) in 8 meals per day, every 3 h. Defaunation was successful and no accidental contamination occurred during the experiment. The protozoa had no significant effect on the volume of rumen digesta, nor on the turnover of the particulate phase. The addition of Isotricha and of the mixed fauna increased the ADF digestibility of the diet but, in the same animals, lowered the in sacco degradation of wheat straw. The ruminal pool sizes of dry matter (DM), organic matter (OM), nitrogen (N), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid lignin detergent (ADL) remained unchanged after protozoa inoculations. The concentration of total volatile fatty acids (VFA) was not altered by faunation with Isotricha or a mixed fauna. The molar proportion of acetate increased at the expense of all the other VFAs (mainly propionate with the mixed fauna). Correspondingly, the proportion of methane in the rumen gases increased and that of CO2 decreased in inoculated animals. The ammonia concentration was highest in animals with a mixed fauna and lowest in those inoculated with Isotricha alone. This trend is explained in terms of the specific effect of the different genera of protozoa on nitrogen metabolism.

Three milk substitute diets, in which the protein was either provided exclusively by skim milk powder or partially (52%) substituted by a native wheat gluten or a potato protein concentrate, were given to intact or ileo-caecal cannulated preruminant calves. The apparent faecal nitrogen digestibility was lower (P < 0.05) with the potato than with the gluten and control diets (0.90, 0.93 and 0.95, respectively). The same trend was observed at the ileal level (0.83, 0.87 and 0.91, respectively). Apparent digestibilities of most amino acids were lower with the potato than with the control diet (P < 0.05 for glutamic acid, proline, cystine, methionine, isoleucine, leucine, tyrosine and lysine). The same trend was observed with the gluten diet. Apparent digestibilities of glutamic acid and cystine were also lower (P < 0.05) with the potato than with the gluten diet. Protein fractions of Mr 43,000 and below 14,000 were detected immunochemically in ileal digesta corresponding to the potato diet, but no immunoreactivity was found in digesta with the gluten diet. However, the considerable enrichment of digesta in glutamic acid and proline with gluten indicates that dietary protein fractions rich in these 2 amino acids escaped digestion in the small intestine. With the potato diet, the undigested fractions contained high levels of aspartic acid, glutamic acid and cystine.

In a preliminary experiment, 3 Rusitec-like fermentors of 1 L capacity were operated under identical conditions. The only difference was the quantity to treated substratum introduced daily into each fermentor: 15 g/d (M15); 40 g/d (M40); and 60 g/d (M60) on a dry matter basis. The fermentation substratum was a rabbit feed that had been digested with amylase and pepsin. The organic matter was lost over 48 h at a significantly higher rate in the M15 fermentor than in M40 and M60: 30.4%, 19.7% and 17.3%, respectively. The pH values observed in M40 and M60 (5.99 and 5.83) were similar to that observed in vivo under ad libitum feeding conditions. The pH was higher in M15 (6.7), as observed in vivo with restricted animals just before the daily meal. The volatile fatty acids (VFA) proportions for C2, C3 and C4 were similar to the in vivo proportion for the 3 fermentors. The daily total VFA production was the largest with M40 but was associated with a poor stability and an excess of minor VFAs. The introduction of 15 g/d was preferred by the authors because of organic matter disappearance rate, pH stability and VFA production. In a second experiment, 4 fermentors were used in the same way as the M15 one, in order to study the reproducibility of the method. Small but significant differences between fermentors were observed for all parameters in relation to a high fermentor stability from 1 day to the next.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of the type of dietary starch (gelatinized vs native) on the biological value of fish meal (FP) and fish soluble protein concentrate (CPSP) was studied through the nitrogen balance in rainbow trout (Oncorhynchus mykiss) reared for 3 weeks at 2 water temperatures: 8 or 18 degrees C. The protein sources were included in diets at a level of 60% and gelatinized or raw starch at a level of 30%. Gelatinized starch improved the biological value of FP and CPSP by reducing the metabolic nitrogen losses. Trout fed the diet with CPSP had a higher nitrogen excretion than those fed the diet with FP. The biological value of both protein sources was unaffected by water temperature.

A mechanistic model describing rumen digestion is presented. The model consists of 22 compartments for classical nutrients, microbes associated with either solids or fluid, and 8 amino-acid compartments. An empirical approach for volatile fatty acids production is used. Sensitivity and behavioural analysis on several parameters demonstrated the need to improve knowledge concerning certain factors. Model results on general criteria are in good agreement with observed data. Validation on 49 experimental lysine and methionine duodenal fluxes were satisfactory. A comparison between observed and predicted values of LysDi and Metdi on several feedstuffs showed good results. This model is a first step in the building of a rumen model suitable for research and application.