Search

In swine industry, hormones are used on sows for a wide variety of indications. Among these hormones we focused on gonadotropins (which stimulate follicular growth and heat behavior) and their use to control or improve sows’ fertility as well as the means that can be implemented to reduce their use. Firstly, we conducted an online survey. This survey was addressed to pig farmers which breed sow. The survey’s goal was to make an inventory of the different breeding practices having an influence on fertility in French pig farms, reproductive problems encountered by farmers and the different uses of hormones in reproductive management. The data collected through this online survey were analyzed to find out if gonadotropin users were similar or different to other farmers. For this we did a univariate analysis with Fisher tests. Then we did a multivariate analysis and carried out two PCAs. One PCA was on the reproduction problems encountered and the other one was toward breeding technique. In our sample of those who responded to the online survey, we were able to observe that gonadotropin users are more birthing sites with a large number of sows and many workers. Farmers who use gonadotropins tend to intervene more and they use more conventional treatments (as opposed to so-called alternative treatments). The use of gonadotropins for some of these users was associated with lower prolificity and a fertility similar to other herds. Analysis suggests that management of heat detection can be improved for some gonadotropins users. This can be a working track in order to reduce or stop gonadotropin use. Secondly, we developed a method for auditing fertility and the use of hormones that aimed to identify risk factors for fertility troubles. This audit aims to find avenues of work to improve fertility in the farms surveyed. If the farmer uses gonadotropins, the questionnaire would aim to propose alternatives to gonadotropins. The audit questionnaire resulted in a RADAR diagram showing the scores obtained in major parts We added to the questionnaire a recording of the housing temperature over three to four weeks and analyzed it. Also, when data were available, an analysis of back fat thickness was added. This audit has been implemented in ten French farms. Individual answers were used to test the questionnaire's ability to describe variability of practices from farm to farm and its ability to identify infertility risk factors. The questionnaire indeed detected variable practices between farms, but no numerical alert threshold could be implemented. This promising tool could be improved by better integration of temperature and backfat monitoring, and testing on larger data set.; Les hormones sont utilisées en production porcine chez la truie pour des indications très variées. Parmi ces hormones nous nous sommes intéressées aux gonadotropines (qui stimulent la croissance folliculaire et la venue en chaleur) et à leur usage afin de maîtriser ou améliorer la fertilité des truies, ainsi qu'aux moyens pouvant être mis en oeuvre pour réduire leur utilisation. Dans un premier temps nous avons réalisé une enquête en ligne. Cette enquête s'adressait aux éleveurs porcins faisant de la reproduction (naisseur et naisseur-engraisseur) et son but était de faire un état des lieux sur les différentes pratiques d'élevages ayant une influence sur la fertilité, les problèmes de reproductions rencontrés et l'usage des hormones dans la gestion de la reproduction. Les données récoltées grâce à cette enquête en ligne ont été analysées afin de chercher si les utilisateurs de gonadotropines étaient comparables aux autres éleveurs. Pour cela nous avons fait une analyse univariée. Puis nous avons réalisé une analyse multivariée avec deux ACP, une sur les problèmes de reproductions rencontrés et une autre sur la conduite d'élevage. Dans notre échantillon ayant répondu à l'enquête en ligne nous avons pu observer que les utilisateurs de gonadotropines sont davantage des sites de naissage avec un grand nombre de truies et beaucoup de personnel. Les éleveurs utilisateurs de gonadotropines sont plus interventionnistes et utilisent plus de traitements conventionnels (par oppositions aux traitements dits alternatifs). L'utilisation de gonadotropines pour une partie de ces utilisateurs était associée à de plus faibles prolificités et à une fertilité semblable aux autres éleveurs. La conduite de la détection des chaleurs est améliorable pour certains éleveurs et peut constituer une piste de travail en vue de diminuer ou d'arrêter l'usage des gonadotropines. Dans un deuxième temps, nous avons élaboré une méthode d'audit de la fertilité et de l'usage d'hormones. Cet audit a pour but de trouver des pistes de travail pour améliorer la fertilité dans les élevages enquêtés et chez les utilisateurs de gonadotropines, le questionnaire a pour but de proposer des alternatives personnalisées. Le questionnaire d'audit aboutit à un diagramme RADAR représentant les notes obtenues par thématique. A cela s'ajoute une analyse des températures sur trois à quatre semaines et lorsque les données sont disponibles une analyse des épaisseurs de lard dorsal. Cet audit a été testé dans dix élevages. Le questionnaire permet de mettre en évidence des différences entre les élevages et pourrait être une aide afin d'identifier des facteurs de risques vis-à-vis de la fertilité. Toutefois aucun seuil d'alerte chiffré n'a pu être défini dans notre étude. La pertinence de cet outil reste à confirmer en intégrant des élevages aux performances plus diversifiées et des monitorings d'ambiance et d'état corporel. Systématiques.

L’industrie porcine met beaucoup d’efforts pour contrôler la contamination par Salmonella en fin de production. Malgré tout, d’après des données européennes de la European Food Safety Authority (EFSA), les produits de viande porcine pourraient être responsables de 10 à 20 % des cas rapportés de salmonellose chez l’Homme. Il semble donc qu’une approche incluant des actions en amont, c’est-à-dire à la ferme, pourrait permettre de réduire la pression de contamination au niveau de l’abattoir et donc la contamination de la viande. Le transfert de Salmonella entre les truies contaminées et les porcelets pourrait être une source importante de contamination dans la filière porcine. Cependant au Canada peu d’information est disponible sur cette voie d’introduction. Nous avons donc décrit le lien entre les souches retrouvées chez les truies et celles retrouvées chez leurs porcelets dans les étapes subséquentes d’un système de production commercial Québécois. De plus, l’établissement du microbiote intestinal chez le porc en production est directement influencé par le microbiote maternel et celui-ci influence l’excrétion de Salmonella chez les porcs en engraissement. Dans cette étude, nous avons donc tout d’abord décrit, dans ce même système, le microbiote des truies en lien avec leur excrétion de Salmonella. Nous avons ensuite décrit le microbiote des porcelets et des porcs en engraissement en relation avec ce microbiote maternel et avons tenté d’identifier des déterminants de l’excrétion qui peuvent être transférés de la truie à sa progéniture à l’intérieur de cette pyramide de production. Pour ce faire, nous avons tout d’abord échantillonné les matières fécales de truies à différents moments de la gestation dans une maternité. Une détection de Salmonella a été effectuée et les populations bactériennes retrouvées dans le microbiote fécal de ces truies ont été décrites par séquençage à haut débit de type MiSeq. Ceci nous a permis de mettre en évidence une réduction significative du niveau de Salmonella excrétées par ces truies entre le début et la fin de la gestation. Nous avons aussi pu mesurer des variations dans le microbiote fécal de celles-ci selon l’excrétion de Salmonella, mais aussi selon le moment de la gestation. Un séquençage a aussi été effectué sur les fèces des porcelets nés de ces truies avant leur sevrage. Ceci nous a permis de démontrer que le statut d’excrétion de la truie influence leur microbiote fécal. Cependant, aucun transfert direct de taxon spécifique de cette relation n’a pu être mesuré. De plus, indépendamment du statut d’excrétion de Salmonella des truies, nous avons démontré qu’à ce moment les porcelets d’une portée avaient des microbiotes fécaux plus semblables entre eux que comparativement à ceux de leurs contemporains, confirmant l’influence de la truie sur le microbiote des porcelets dans les fermes échantillonnées. Finalement, des échantillonnages de matière fécale de ces porcs ont aussi été effectués en engraissement. Leur statut d’excrétion de Salmonella et la composition de leur microbiote ont aussi été évalués à cette étape. Grâce à ces échantillons, nous avons démontré que, dans le système de production étudié, le statut d’excrétion de la truie n’avait pas d’impact sur le microbiote des animaux après l’étape du sevrage. Nous avons cependant démontré que dans les fermes faisant partie de l’étude, les porcs nés d’une même mère avaient toujours un microbiote fécal différenciable de celui de leurs congénères. Ceci suggère ainsi le potentiel d’actions visant à moduler le microbiote intestinal de la truie et qui pourrait être transféré au bénéfice de leurs porcelets. Nous avons aussi décrit par typage, à l’aide de courbes de fusion à haute résolution (HRM), la circulation et le transfert des Salmonella de la maternité vers les autres étapes de la production dans cette pyramide de production. Les résultats obtenus démontrent ici que, malgré une excrétion des truies dans la période périnatale, les souches retrouvées plus tard chez les porcelets en pouponnière et dans leur environnement ont des profils HRM différents de celles retrouvées en maternité. Les truies auraient donc, dans le système de production étudié, un effet marginal sur la contamination des porcelets et ceux-ci se contamineraient plutôt dans l’environnement de la pouponnière ou de l’engraissement. Cette étude a permis de mieux décrire la présence de Salmonella dans un système de production porcine commercial au Québec et ainsi de mieux comprendre l’impact de la transmission de Salmonella entre les truies et les porcelets. Ces nouvelles connaissances permettront de mieux cibler les étapes où des mesures efficaces pourraient être implantées pour réduire la contamination du produit fini. L’étude du microbiote a aussi permis de mettre en évidence une influence de la truie sur le microbiote fécal de ses porcelets et ce jusqu’en engraissement, sans pour autant avoir pu identifier de taxons directement transférés, ni avoir pu mesurer d’effet de cette influence sur l’excrétion de Salmonella. Néanmoins, au-delà de la problématique spécifique de Salmonella, cette étude ouvre des perspectives de modulation du microbiote intestinal de la truie au bénéfice de l’orientation du microbiote digestif du porc pendant toute la production, microbiote dont les effets sur la santé et le bien-être sont de mieux en mieux documentés., The pork industry is putting a lot of effort into controlling Salmonella contamination at the end of production. However, according to the European Food Safety Authority (EFSA) data, pig meat products may be responsible for 10-20% of reported cases of salmonellosis in humans. It therefore seems that an approach including actions upstream, on the farm, could make it possible to reduce the pressure of contamination at the slaughterhouse and therefore the contamination of the meat. The transfer of Salmonella between contaminated sows and piglets could be an important source of contamination in the pig sector. However, in Canada little information is available on this route of introduction. We have therefore described the link between the strains found in sows and those found in their piglets in the subsequent stages of production in a Quebec commercial production system. In addition, the establishment of this microbiota in pigs in production is directly influenced by the maternal microbiota and that the intestinal microbiota influences the excretion of Salmonella in fattening pigs. In this study, we therefore first described the microbiota of sows in relation to their excretion of Salmonella in this same production system. We then described the microbiota of piglets and fattening pigs in relation to this maternal microbiota and attempted to identify determinants of shedding that can be transferred from the sow to its offspring within this production pyramid. To do this, we first sampled the feces of sows at different times of gestation in a maternity unit. Salmonella was detected and the bacterial populations found in the fecal microbiota of these sows were described by high-throughput sequencing of the MiSeq type. This allowed us to highlight significant variations in the level of Salmonella excreted by these sows at different times of gestation. We were also able to measure variations in the fecal microbiota of these depending on the excretion of Salmonella, but also according to the time of gestation. Sequencing was also carried out on the feces of piglets born from these sows before weaning. This allowed us to demonstrate that the sow's shedding status influences their fecal microbiota. However, no direct taxon transfer specific to this relationship could be measured. In addition, up to the nursery, we have demonstrated that piglets from the same litter have more similar fecal microbiota than compared to other contemporary animals, confirming the influence of the sow on the piglet microbiota in the sampled farms. Finally, fecal samples from these pigs were also carried out for fattening. Their Salmonella excretion status and the composition of their microbiota were also assessed at this stage. Using these samples, we demonstrated, in the production system that was studied, that the impact of the sow’s status on the microbiota was not retained for fattening after the weaning stage and did not affect the risk of shedding during fattening. However, we have shown that on the farm included in our study that pigs born to the same mother always have a differentiated fecal microbiota from that of their counterparts. This thus demonstrates the potential for actions aimed at modulating the intestinal microbiota of the sow and which could be transferred to the benefit of their piglets. We have also described by High Resolution Melt typing (HRM) the circulation and transfer of Salmonella from the maternity to the other stages of production in this production pyramid. The results obtained demonstrate here that despite the excretion of sows in the perinatal period, the strains found later in the piglets at the nursery and their environment have different HRM profiles from those found in maternity. In the studied production system, sows would therefore have a marginal effect on the contamination of piglets in the production system studied, compared to the environment in the nursery among other things. This study made it possible to better describe the circulation of Salmonella in a commercial swine production system in Quebec and thus to better understand the impact of Salmonella transmission between sows and piglets. This new knowledge will allow us to better target the stages where effective measures could be implemented to reduce contamination of the finished product. The study of the microbiota also made it possible to highlight an influence of the sow on the fecal microbiota of its piglets and this until fattening, without being able to identify taxa directly transferred nor to have been able to measure the effect of this influence on the excretion of Salmonella. However, beyond the specific problem of Salmonella, this study opens up perspectives for modulating the intestinal microbiota of the sow for the benefit of the orientation of the digestive microbiota of pigs throughout production, a microbiota whose effects on health and well-being are getting increasingly well documented.

Visio-conférence; International audience

Visio-conférence; International audience

International audience; Un logiciel de vision artificielle contenant des fonctions de traitement d'image et d'intelligence artificielle a été développé pour détecter des animaux sur des vidéos enregistrées par des pièges photographiques en milieux forestiers. Le suivi par pièges photographiques est utilisé sur le dispositif expérimental OPTMix en forêt d'Orléans pour estimer la fréquentation des placettes de mesure par les ongulés sauvages (chevreuil, cerf élaphe et sanglier). Les scientifiques et les naturalistes utilisent le suivi par pièges photographiques pour inventorier et suivre les populations animales et la biodiversité de la faune sauvage. De nombreuses vidéos obtenues ont été analysées manuellement par les agents de l'INRAE, qui sauvegardent des informations telles que la parcelle forestière sur laquelle la détection animale est effectuée, la date de la vidéo, les plages horaires de présence animale, l'espèce et la catégorie d'animal détecté, et leur comportement. Pour éviter cette tâche fastidieuse manuelle et rendre ce programme de surveillance de la biodiversité à grande échelle plus accessible aux gestionnaires et autres utilisateurs finaux, un logiciel de vision, qui comprend des opérations de traitement d'images et des méthodes d'intelligence artificielle (trois réseaux de neurones intégrés développés avec les outils Tensorflow, Pytorch et Caffe), a été développé pour détecter, compter et identifier les espèces animales et enregistrer d'autres données auxiliaires, sur les vidéos, en tenant compte des contraintes telles que les conditions d'éclairage très variables dans le sous-bois, les variations de couleur des objets naturels (arbres, herbes, animaux) et les mouvements d'herbe qui ajoutent du bruit aux images. Le logiciel développé permet également de détecter les animaux partiellement cachés par des objets naturels (arbres, herbes,…). Une méthode d’intelligence artificielle a été développée pour estimer la posture des truies, parmi quatre postures principales (debout, couché ventre, assis, allaitement) dans des fermes en milieu clos, dans le but de déterminer la durée de chaque posture, pour une truie donnée, au cours du temps, pour des opérations d’élevage de précision (qualité de l’élevage, réduction de la mortalité des porcelets,...) Un réseau de neurones a été créé, à partir d’une base d’apprentissage de 30000 images de postures de truie, en utilisant l’outil Tensorflow et un réseau de type Inception V3, pour obtenir un système de prédiction, en temps réel avec une fréquence de 10Hz.

Les besoins nutritionnels des truies varient au cours du temps pour un individu, ainsi qu'entre les individus, alorsqu'en pratique le même aliment est généralement distribué à toutes les truies. Les nouvelles technologies dephénotypage en temps réel des truies, de contrôle du milieu d'élevage et de distribution des aliments,permettent d'envisager de nouvelles perspectives de modélisation pour améliorer l'efficience alimentaire, réduirele coût de production et diminuer les impacts négatifs de l'élevage sur l'environnement. Il s'agit donc dedévelopper des modèles nutritionnels qui permettent dans un premier temps (i) d'ajuster des recommandationssur la base de données historiques d'élevage en prenant en compte la variabilité individuelle et dans un deuxièmetemps (ii) de piloter en temps réel des équipements de préparation des rations pour une alimentation deprécision permettant d'apporter une ration adaptée chaque jour aux besoins de chaque truie. Deux modèles ontété ainsi développés pour la gestation (Gaillard et al., 2019) et pour la lactation (Gauthier et al., 20 19), puis testés sur une base de données constituée de 2511 gestations et 1450 lactations. La compréhension des facteurs de variabilité individuelle des besoins nutritionnels permet de définir des stratégies d'alimentation par groupe (en fonction du stade gestation, du rang de portée), puis par individu et par jour. Les résultats indiquent que l'alimentation de précision, obtenue en mélangeant deux aliments qui diffèrent par leurs teneurs en nutriments, permet de réduire d'environ 27% et 8% les apports de lysine, respectivement en gestation et en lactation, comparativement à l'alimentation conventionnelle (un aliment par stade). De plus, une proportion plus élevée de truies ont leurs besoins couverts en fin de gestation et lactation, notamment les plus jeunes, alors qu'une proportion plus faible est suralimentée en début de gestation et lactation, notamment les plus âgées.Ces résultats confirment l'intérêt de la prise en compte de la variabilité individuelle dans la détermination desbesoins nutritionnels pour mieux couvrir les besoins de la population tout en réduisant les gaspillagesalimentaires et les pertes dans l'environnement. Ces systèmes d'aide à la décision sont actuellement testés enstation expérimentale (UEPR, Saint-Gilles) afin d'utiliser des données en temps réel qui pourront également servirà améliorer les modèles (données d'activité et de température).

The gestating and lactating sow as other mammals develops an insulin resistance which means a decrease of insulin efficiency. This happens to improve the income of glucose for the fetuses during gestation and for the mammary glands during lactation. But, sometimes sows are too much insulin resistant and develop a gestational diabetes. In this case, piglets born with a lower vitality and with hypoglycemia few hours after birth. It causes a greater mortality at birth...; En fin de gestation et en lactation, les mammifères et notamment la truie développent une résistance à l’insuline qui se traduit par une efficacité moindre de l’insuline dans le but de favoriser l’apport en glucose aux fœtus ou aux glandes mammaires. Cependant, dans certains cas la résistance est trop importante et laisse place à un diabète gestationnel. Les porcelets naissent avec une moins bonne vitalité et sont en hypoglycémie quelques heures après la naissance ce qui augmente le risque de mortinatalité...

International audience; The objective was to develop a tool to measure sow postural activity during lactation while kept between fences in the farrowing crate. Several trials were carried out to select sensors and test their ability to detect 5 different positions of the sow. First, several sensors, placed in a single metal box, were attached to the upper part of the back of sows with a custom-built belt that passes underneath the belly, just behind the front legs. For validation of the positions predicted from sensor data, sow behaviour was recorded with use of a digital camera and video records were analysed by a single observer. Prediction ability was tested with machine learning applied to random forests for the three-axis data provided by the sensors in the X, Y and Z dimensions. When comparing information provided by three sensors, i.e. two accelerometers (sensors A and B) and an application developed for a smartphone (sensor C), one sensor detected five positions more accurately than the other two. The error rate of prediction from 30% of the data was 2.1% with sensor A, 3.1% with sensor B, and 4.8% with sensor C. Additional trials focused on the ability of sensor A to distinguish among the five positions, using five sows. Statistical sensitivity was 0.94 and 0.95 for the right and left lateral positions, respectively; 0.79 for the ventral position; 0.75 for the standing position; but only 0.33 for the sitting position (because it represented only 4% of sows’ time budget). One single axis was sufficient to detect the two lateral positions. Next, we concentrated our interest on the advantages and drawbacks of 2 accelerometers: we ran new trials to compare outputs from sensor A with those obtained with a sensor D. We used acquisition speeds varying from 1 to 16 obs/sec to optimize the sampling rate to detect positions accurately and to test if postural changes at risk for the piglets can be detected. Analyses are in progress. The use of accelerometers to measure finely the postural activity of lactating sows is promising.

Effects of gestational heat stress on sow and progeny performance at farrowing. 70. Annual Meeting of the European Federation of Animal Science (EAAP)

La couverture des besoins nutritionnels pendant la lactation est très dépendante de la production laitière et de la consommation d’aliment, et varie largement entre les truies. En pratique, l’ajustement des apports alimentaires aux besoins individuels est difficile car les besoins sont établis à partir des performances moyennes du troupeau. L’acquisition de données à haut débit sur l’animal et son environnement permet d'envisager le développement de systèmes d’alimentation de précision. Le modèle développé combine les connaissances récentes sur l’utilisation des nutriments par la truie allaitante avec les données disponibles en élevage sur les truies à la mise-bas (rang, poids vif, épaisseur de lard dorsal) et sur leurs performances individuelles (ingestion journalière d'aliment de la truie, taille de portée et gain moyen quotidien des porcelets) pour estimer leurs besoins nutritionnels journaliers et par kg d’aliment. L’approche est testée sur une base de données constituée de 1450 lactations. Les effets de l’élevage (A, B), de la semaine de lactation (S1, S2 et S3+) et du rang de portée (P1, P2 et P3+) sont significatifs sur les performances des truies et sur leurs besoins journaliers en énergie métabolisable, lysine et phosphore digestibles. Le besoin moyen en lysine digestible par kg d’aliment est plus bas en S1 (6,4 g/kg), puis se stabilise en S2 (8,0 g/kg) et S3+ (7,8 g/kg). Il est plus bas pour les truies P3+ (6,7 g/kg) et P2 (7,3 g/kg) que P1 (8,3 g/kg) du fait de l’ingestion plus élevée des truies multipares. Les évolutions du besoin en phosphore selon la semaine et le rang sont comparables. L’utilisation des données d’élevage permet d’intégrer l’effet de la variabilité des performances sur les besoins nutritionnels individuels des truies allaitantes. En pratique, les besoins individuels pendant la lactation pourraient être mieux couverts par une alimentation de précision., Meeting nutritional requirements during lactation depends on milk yield and feed intake and varies among sows. In practice, meeting nutritional supplies and individual requirements is difficult because requirements are established at the herd scale from average performance. Acquiring data on sows and their environment at high-throughput allows the development of new precision feeding systems. The model developed combines current knowledge about nutrient use during lactation with on-farm data available on lactating sows at farrowing (parity, body weight, backfat thickness) and on their individual performances (litter size, average daily gain of the litter, sow daily feed intake) to estimate nutritional requirements per day and per kg of feed. The approach was tested on a database of 1450 lactations. The effect of farm (A, B), week of lactation (W1, W2 and W3+) and parity (P1, P2 and P3+) were significant on sow performances and on their daily requirements for metabolizable energy, digestible lysine and phosphorus. The average required dietary concentration of digestible lysine was low at W1 (6.4 g/kg) and then stabilised at W2 (8.0 g/kg) and W3+ (7.8 g/kg). It was lower for P3+ (6.7 g/kg) and P2 sows (7.3 g/kg) than P1 sows (8.3 g/kg) due to the higher feed intake of multiparous sows. The changes in digestible phosphorus requirements according to week of lactation and parity were similar. The use of on-farm data allows to integrate the effect of performance variability on individual requirements in lactating sows. In practice, individual requirements during lactation could be better met with a precision feeding strategy.

L’adoption de l’alimentation de précision en production porcine passe par une évaluation précise de ses avantages potentiels. L’objectif de cette étude était d’évaluer en milieu commercial et dans un mode de gestion des truies en groupe l’impact d’une alimentation de précision sur les performances, la productivité et le coût d’alimentation en gestation. Une alimentation conventionnelle (C ; 0,53 % lysine digestible) et une alimentation de précision (AP ; teneur en lysine digestible variant en fonction du jour de gestation et du rang de portée) ont été comparées. Quatre bandes consécutives ont été étudiées dans un élevage commercial sur deux cycles complets, de la saillie jusqu’au sevrage, correspondant à 295 truies et 523 portées. Sur l’ensemble des truies, le gain d'épaisseur de muscle pendant la gestation était significativement supérieur chez les truies AP. Chez les truies multipares, aucun autre impact n’a été observé alors que chez les truies nullipares, le taux de survie des porcelets à la mise bas tendait à être meilleur pour les truies du traitement AP (P = 0,08). Considérant que ce traitement permet une meilleure couverture des besoins en acides aminés des truies nullipares en fin de gestation, ce résultat semble logique. Il reste toutefois à le confirmer sur un nombre plus élevé d'animaux. Les résultats de cette étude montrent que l’AP chez la truie en gestation permet de réduire les apports totaux de protéines et d'acides aminés sans affecter négativement les performances permettant ainsi de réduire de près de 2 € le coût d’alimentation par truie et par année., Adoption of precision feeding in pork production requires precise assessment of its potential benefits. The objective of this study was to evaluate, in a commercial setting and under group sow management, impacts of precision feeding on growth performance, productivity and feeding costs in gestating sows. Conventional feeding (C; 0.53% digestible lysine) and precision feeding (PF; digestible lysine content varied by gestation day and litter rank) were compared. Four consecutive batches in a commercial farm were studied over two complete cycles, from breeding to weaning, corresponding to 295 sows and 523 litters. For all sows, gestational muscle gain was significantly greater for PF sows. For multiparous sows, no other impact was observed, while for gilts the survival rate of piglets at birth tended to be higher for PF treatment sows (P = 0.08). Since PF covers amino acid requirements of gilts at the end of gestation better, this result seems logical. However, future studies on more animals will be needed to confirm its benefits. The results show that PF of gestating sows can reduce protein and amino acid supplies without negatively affecting the performance of sows, thus reducing the feeding cost per sow per year by €2.

In the recent years, the reproductive performance of sows has been drastically improved. Nowadays, in many farms, with the use of hyperprolific sows, the average litter size exceeds 15 piglets at farrowing and 13 at weaning. These changes in performance have been the major drivers for the evolution of sow's nutritional requirements during pregnancy and lactation. At the same time, a large amount of scientific knowledge has been generated over the past thirty years allowing, with the help of mathematical modelling, a holistic approach of energy, amino acids and minerals supplies to sows. The aim of this chapter is to describe the evolutions in the approach of sows' feeding over the past decades and show how the current state of knowledge on sow nutrition can be used for developing models and decision support tools and improving feeding strategies in practice. Different examples are shown to illustrate how the use of such tools can help in optimizing the productivity of sows. Until recently, the maximization of reproductive performance of sows and their litters has been the main objective considered when defining nutritional supplies. Nowadays, new objectives in relation with the increasing societal concern for animal welfare and environment must also be considered. Pig production systems, as well as other animal production systems, are also questioned by the society at a global level in terms of their overall sustainability and acceptability, and this will affect feeding strategies in the future.

Environmental enrichment is a recognized strategy to improve sow welfare. Providing manipulable wood materials and straw pellets to sows during gestation might participate in satisfying their investigative behavior. Sows may also get a benefit from chewing and eating fibers, which can decrease their hunger. Such strategy, however, should not adversely affect metabolic status of sows and newborn piglets. In this study, gestating sows were group-housed in a conventional system on slatted floor (C, n = 26) or in the same system enriched with pieces of oak attached to a chain and straw pellets (CE, n = 30). Straw pellets were provided in the trough at a rate of 200 g/d from 3 to 30 days of gestation (DG) and 400 g/d from 31 to 104 DG. On DG105, sows were transferred into farrowing pens and housed in identical individual stalls on slatted floor. Sow body weight and backfat thickness were recorded before insemination, on DG105 and at weaning. Plasma concentrations of metabolites and insulin were measured in sows on DG73 and DG102. Blood was also collected from a subset of piglets at birth (n = 6 per litter in 5 C and 8 CE litters) to determine their metabolic and oxidative status. Sow body weight, backfat thickness, and estimated body lipid and protein masses did not differ between treatments during gestation and lactation. Maternal plasma concentrations of glucose, lactate, NEFA, beta‑hydroxy‑butyrate and insulin did not differ between groups (P > 0.10). However, CE sows had lower circulating concentrations of urea (P < 0.001) and a greater increase in triglyceride concentrations between DG73 and DG102 (P < 0.05). Treatment did not influence (P > 0.10) piglet birth weight or plasma concentrations of glucose, fructose, lactate and albumin, antioxidant potential and the oxidative stress index in newborns. On the day after farrowing, the milk produced by CE sows contained more minerals (P < 0.01) than the milk of C sows but similar contents of protein, fat, lactose, energy and IgA. The proportion of piglets that died at birth and within 12 h of birth was lower in CE than in C litters (P < 0.05), but overall mortality (stillbirth + preweaning death) did not differ between the two groups. To conclude, providing manipulable materials and straw pellets to sows during gestation had little impact on sow metabolic status but improved early neonatal survival.

Colostrum plays an essential role in ensuring the survival, growth and health of piglets by providing energy, nutrients, immunoglobulins, growth factors and many other bioactive components and cells. Both colostrum yield and composition are highly variable among sows, yet mechanisms and factors that regulate colostrogenesis are not fully known. Unlike sow milk yield, sow colostrum yield is not highly determined by litter size and suckling intensity but is largely driven by sow-related factors. Colostrum synthesis is under hormonal control, with prolactin and progesterone concentrations prepartum having, respectively, positive and negative influences on colostrum yield. Less is known about the endocrine control of the end of colostrogenesis in swine, which is characterized by the closure of tight junctions in the mammary epithelium and the cessation of transfer of immunoglobulin G (IgG) into lacteal secretions. Recent studies indicate that exogenous hormones may influence colostrogenesis. Inducing parturition by injecting prostaglandin F2α on day 114 of gestation in combination with an oxytocin-like molecule reduced colostrum yield, and injection of prostaglandin F2α alone either reduced colostrum yield or had no effect. Injecting a supraphysiological dose of oxytocin to sows in the early postpartum period delayed the tightening of mammary tight junctions, thereby prolonging the colostral phase and increasing concentrations of IGF-I and IgG and IgA in early milk. The development of strategies to improve colostrum composition in swine through maternal feeding has been largely explored but very few attempts were made to increase colostrum yield. This is most likely because of the difficulty in measuring colostrum yield in swine. The fatty acid content of colostrum greatly depends on the amount of lipids provided in the sow diet during late gestation, whereas the fatty acid profile is largely influenced by the type of lipid being fed to the pregnant sow. Moreover, various ingredients that presumably have immuno-modulating effects (such as fish oil, prebiotics and probiotics) increased concentrations of IgG, IgA and/or IgM in sow colostrum when they were provided during the last weeks of gestation. Finally, there is some evidence that sow nutrition during late gestation may influence colostrum yield but this clearly warrants more research. This review emphasizes that although progress has been made in understanding the control of colostrogenesis in swine, and that strategies exist to manipulate fat and immunoglobulin contents of colostrum, ways to increase colostrum yield are still lacking.

The objectives were to examine effects of litter size on insulin sensitivity in multiparous sows at the end of pregnancy. Twelve sows were allocated in two treatments after weaning: control (CTR) or ligature of the left oviduct (LIG). At 68 d of the subsequent pregnancy, catheters were implanted in a jugular vein, in a carotid artery, and in the main vein draining one uterine horn. A blood flow probe was fitted around the artery irrigating the same uterine horn. A meal test, a tolerance test, and an euglycemic hyperinsulinemic clamp test were performed at 108 ± 3 d of pregnancy. Serial blood samples were drawn simultaneously from the uterine vein and the carotid artery before and during the tests. The number of fetuses in the studied uterine horn was lower (3.7 vs. 8.0, P < 0.001), and piglets at birth were heavier (1.71 vs. 1.31 kg, P = 0.04) in the LIG sows than in the CTR sows. Treatment did not affect uterine blood flow (UBF), but UBF/fetus in the uterine horn was greater for the LIG treatment (0.67 vs. 0.34 L/min, P = 0.002). During meal test, glycemia, glucose uptake in the uterine horn and glucose uterine uptake/fetus were similar in both groups of sows, while insulin levels were higher in the LIG sows (P = 0.04). The decrease of NEFA concentrations was similar across treatments. Glucose half-life did not differ between treatments (13.4 min as a mean; P = 0.63) during tolerance test, but area under the insulin curve was greater in the LIG sows (P = 0.02). The glucose infusion rate during euglycemic hyperinsulinemic clamps was lower in the LIG sows than in CTR sows (6.1 ± 0.2 vs. 7.8 ± 0.1 mg glucose.kg−1 min−1; P = 0.01). The LIG sows are less sensitive to insulin than the CTR sows without adjustment of maternal glycemia and glucose tolerance. Insulin sensitivity adaptation to litter size in late pregnancy of sows would rather be connected to growth rate than to number of fetuses.

International audience; Sows often receive the same feed during gestation even though their nutrient requirements vary during gestation and among sows. The objective of this study was to report the variability in nutrient requirement among sows and during gestation, in order to develop a precision feeding approach. A dataset of 2511 gestations reporting sow characteristics at insemination and their farrowing performance was used as an input for a Python model, adapted from InraPorc®, predicting nutrient requirement during gestation. Total metabolizable energy (ME) requirement increased with increasing litter size, gestation weeks, and parity (30.6, 33.6 and 35.5 MJ/d for parity 1, 2 and 3 and beyond, respectively, P < 0.01). Standardized ileal digestible lysine (SID Lys) requirement per kg of diet increased from week 1 to 6 of gestation, remained stable from week 7 to 10, and increased again from week 11 until the end of gestation (P < 0.01). Average Lys requirement increased with increasing litter size (SID Lys: 3.00, 3.27, 3.50 g/kg for small, medium and large litters, P < 0.01) and decreased when parity increased (SID Lys: 3.61, 3.17, 2.84 g/kg for parity 1, 2 and 3++, P < 0.01). Standardized total tract digestible phosphorus (STTD-P) and total calcium (Total-Ca) requirements markedly increased after week 9, with litter size, and decreased when parity increased (STTD-P: 1.36 vs 1.31 g/kg for parity 1 and parity 3 and beyond; Total-Ca: 4.28 vs. 4.10 g/kg for parity 1 and parity 3 and beyond, P < 0.01). Based on empirical cumulative distribution functions, a 4-diets strategy, varying in SID Lys and STTD-P content according to parity and gestation period (P1 from week 0 to 11, P2 from week 12 to 17), may be put forward to meet the requirements of 90% of the sows (two diets for multiparous sows: P1: 2.8 g SID Lys/kg and 1.1 g STTD-P/kg; P2: 4.5 g SID Lys/kg and 2.3 g STTD-P/kg; and two diets for primiparous sows: P1: 3.4 g SID Lys/kg and 1.1g STTD-P/kg; P2: 5.0 g SID Lys/kg, 2.2 g STTD-P/kg). Better considering the high variability of sow requirement should thus make it possible to optimize their performance whilst reducing feeding cost and excretion. Feeding sows closer to their requirement may initially be achieved by grouping and feeding sows according to gestation week and parity, and ultimately by feeding sows individually using a smart feeder allowing the mixing of different feeds differing in their nutrient content.

International audience; Estrus synchronization is important for optimal management of gilt reproduction in pig farms. Hormonal treatments, such as synthetic progestogens, are used on a routine basis, but there is a growing demand for non-hormonal alternative breeding tools. Before puberty, gilts exhibit a ‘waiting period,’ related to the ovarian development and gonadotrophin secretions, during which external stimulations, such as boar exposure, could induce and synchronize first ovulation. Practical non-invasive tools for identification of this period in farms are lacking. During this period, urinary oestrone levels are high, but urine sampling is difficult in group-housed females. The aim of this work was to search for specific biomarkers of the ‘waiting period’ in saliva and urine. In total, nine 144- to 147-day-old Large White gilts were subjected to trans-abdominal ultrasonography three times a week for 5 weeks until puberty detection (week –5 to week –1 before puberty). Urine and saliva samples were collected for oestrone assay to detect the ‘waiting period’ and for metabolome analysis using 1H-nuclear magnetic resonance spectroscopy to detect potential biomarkers of the ‘waiting period.’ Gilts were slaughtered 7 days after puberty detection for puberty confirmation. Results were consistent with ultrasonography data for six gilts. Urine and saliva samples from these six gilts were analyzed. Urinary estrone concentration significantly increased 2 weeks before puberty detection. Metabolome analysis of urine samples allowed the identification of 78 spectral bins, among them, 42 low-molecular-weight metabolites were identified. Metabolome analysis of salivary samples allowed the identification of 59 spectral bins, among them, 23 low-molecular-weight metabolites were detected and 17 were identified. No potential biomarker was identified in urinary samples. In saliva, butyrate and 2HOvalerate, 5.79 ppm (putatively uridine), formate, malonate and propionate could be biomarker candidates to ascertain the pre-puberty period in gilt reproduction. These results confirm that non-invasive salivary samples could allow the identification of the physiological status of the gilts and presumably the optimal time for application of the boar effect. This could contribute to synchronize puberty onset and hence to develop non-hormonal breeding tools.

Even though animals are from the same genetic line, farmers have to cope with variability both in sows and piglets. In sows, variability is observed in traits such as parity, prolificacy, appetite, body weight (BW) and back fat thickness (BF). For instance, at the beginning of gestation, variability in body condition among sows can be high due to parity and age. In addition, at a given age, variability in litter size, milk potential, and appetite results in different nutrient requirements and consequently in variability of changes in maternal body reserves. Variability in BF can be a problem as several studies have indicated that too high or too low BF values are to be avoided at farrowing as well as at weaning. In both cases, the longevity of the sow is impaired, and farmers are advised to manage the sows toward a target BF depending on the physiological stage, associated with an age-dependant BW, increasing with age up to mature BW. In addition, variation in sow’s body condition at farrowing and in prolificacy influences the new born and weaning piglet traits. Compared to less prolific sows, high-prolific sows farrow more piglets, which are both lighter on average and more heterogeneous. Compared to normal birthweight piglets, the survival rate of low birthweight piglets is lower. Providing additional care around birth helps these piglets to survive, but subsequent housing and feeding management have to be adapted to deal with the variability in their growth potential. Nutritional strategies (based on modelling approaches that take into account criteria that influence requirements) are suggested to optimise the expression of the animals’ potential, but most often without an intention to reduce inter-individual variability in growth performance. In order to control or reduce variability, other solutions have been evaluated in experimental studies that focus on the level and the dynamic of the feeding plan and the quality of the diet. The challenge is now to validate these solutions in production units, which will be more or less easy depending on the existing housing and feeding systems, and the economic, welfare and environmental context.

Because of their intense metabolism, lactating sows are highly sensitive to high ambient temperature, which induces a reduction in their voluntary feed intake and milk production. This also results in a decrease in piglet weight gain and an increase in the mobilization of body reserves, which may impair reproduction after weaning. In the context of climate change which increases average temperature and the frequency of periods of heat stress, the aim of this work was to quantify the relationships between ambient temperature and sow and piglet performance, and to use these relationships in a prediction model of nutrient utilization by sows. A database with 46 publications and 254 observations was built in order to adjust prediction equations for different criteria such as feed intake, respiratory frequency, body temperature, litter growth, and milk production. These equations were then incorporated into a simulation model including (1) a bioclimatic module predicting the effect of outdoor temperature on the indoor temperature perceived by the sow and (2) a nutrition module predicting the effect of temperature on feed intake, milk production, energy and amino-acid utilization, and body reserves. This enabled a decision support tool to be developed for the prediction of performance and nutritional requirement of lactating sows in different climatic conditions. The model was used to simulate the effect of climate change on sow’s and piglets’ performance using CLIMATOR climate database for West and South France. The results show highly significant effects of season and region on animal performance and nutritional requirements. The simulations performed for years 2045-2050 indicate that these effects tend to become more marked with climate change. For instance digestible lysine requirement per kg feed was on average 10% higher during summer than during winter, and the requirement simulated for period 2045-2050 was about 2% higher than for 2000-2005. In practice the model developed should enable feed composition to be better adapted to the season and to the geographical location of farms and to expected changes of climate for the future.

National audience; L’enrichissement de la loge de maternité par la mise à disposition d’un matériau manipulable avant la mise-bas, est une voie d’amélioration du bien-être des truies en permettant l’expression d’un comportement de nidification. Une étude a été conduite sur 32 truies de race Large-White Landrace, logées individuellement dans une case de maternité de type « liberté », à savoir libre à l’entrée, bloquées en salle de contention juste avant la mise-bas puis libérées à 7 jour postpartum jusqu’au sevrage. La case était équipée d’une toile de jute avant la mise-bas (lot Jute, toile retirée à la fin de la mise-bas) ou sans apport (lot Témoin). Pour évaluer leur tempérament, les truies étaient soumises à des tests de réactivité (objet nouveau, présence humaine, soins aux jeunes par humain) avant et/ou après la mise-bas, et observées en vidéo en phase peripartum ou de visu lors de séquences de couchage à leur libération. L’analyse a porté sur l’effet de l’apport de matériau manipulable et du tempérament des animaux sur le comportement maternel à la parturition ou en phase de lactation. Notre étude a montré une utilisation de la toile comme matériau de nidification, mais sans aucun effet sur le comportement maternel à la parturition ou en phase de lactation (P>0,10). L’analyse des réponses lors des tests de réactivité avant la mise-bas (néophobie, homme ; ACP- CAH)) a décrit deux groupes de truies se différenciant par leur néophobie vis-à-vis d’un objet nouveau (élevé ou faible). Ce trait du tempérament n’a pas eu d’effet sur le comportement maternel. Par contre, l’apport de la toile de jute diminue le nombre d’écrasements chez les truies les moins néophobes mais l’augmente dans le cas de truies les plus néophobes. Cette étude souligne l’importance des caractéristiques individuelles des truies (expérience, tempérament) et de l’environnement prénatal sur le développement du comportement maternel et ses conséquences économiques associées à la survie des porcelets. La distribution de matériaux de nidification dans les élevages de production reste à préciser pour son application fonctionnelle.

Background The degree of adipose tissue development at birth may influence neonatal survival and subsequent health outcomes. Despite their lower birth weights, piglets from Meishan sows (a fat breed with excellent maternal ability) have a higher survival rate than piglets from Large White sows (a lean breed). To identify the main pathways involved in subcutaneous adipose tissue maturation during the last month of gestation, we compared the proteome and the expression levels of some genes at d 90 and d 110 of gestation in purebred and crossbred Large White or Meishan fetuses gestated by sows of either breed. Results A total of 52 proteins in fetal subcutaneous adipose tissue were identified as differentially expressed over the course of gestation. Many proteins involved in energy metabolism were more abundant, whereas some proteins participating in cytoskeleton organization were reduced in abundance on d 110 compared with d 90. Irrespective of age, 24 proteins differed in abundance between fetal genotypes, and an interaction effect between fetal age and genotype was observed for 13 proteins. The abundance levels of proteins known to be responsive to nutrient levels such as aldolase and fatty acid binding proteins, as well as the expression levels of FASN, a key lipogenic enzyme, and MLXIPL, a pivotal transcriptional mediator of glucose-related stimulation of lipogenic genes, were elevated in the adipose tissue of pure and crossbred fetuses from Meishan sows. These data suggested that the adipose tissue of these fetuses had superior metabolic functionality, whatever their paternal genes. Conversely, proteins participating in redox homeostasis and apoptotic cell clearance had a lower abundance in Meishan than in Large White fetuses. Time-course differences in adipose tissue protein abundance were revealed between fetal genotypes for a few secreted proteins participating in responses to organic substances, such as alpha-2-HS-glycoprotein, transferrin and albumin. Conclusions These results underline the importance of not only fetal age but also maternal intrauterine environment in the regulation of several proteins in subcutaneous adipose tissue. These proteins may be used to estimate the maturity grade of piglet neonates. Electronic supplementary material The online version of this article (10.1186/s40104-018-0244-2) contains supplementary material, which is available to authorized users.

Perinatal nutrition plays a decisive role in controlling gut bacterial primo-colonization and, thereby, is an important driver of the development and maturation of intestinal immunity. Since a short-chain fructooligosaccharide (scFOS) prebiotic was known to modulate microbiota, our study evaluated effects of such supplementation on intestinal immunity development and functionality of piglets. Sows received a standard diet supplemented with scFOS or not (CTRL) for the last third of gestation and the entire lactation. Intestinal immune system maturation was assessed at PND 21 during lactation. At postnatal day (PND) 28, piglets were weaned on a CTRL or scFOS diet for four to seven weeks. Then, during the post-weaning period, two vaccine challenges were performed individually; one vaccine directed against Influenza respiratory virus and the other directed against the intestinal bacterium Lawsonia intracellularis, to assess immune responsiveness later in life. Maternal scFOS supplementation stimulated the development of the offspring intestinal immune system before weaning. Such improvement induced beneficial effects on its functionality, later in life, by enhancing local defense mechanisms (number of goblet cells and cytokine secretion) and responsiveness to a bacterial vaccine challenge (production of specific antibodies). Interestingly, the maternal scFOS supplementation improved the immune response to L. intracellularis vaccine, but not that to the vaccine directed against the Influenza respiratory virus. The direct scFOS supplementation of weaned piglets increased the response to Influenza challenge, but not to L. intracellularis vaccine. Thus, the window of nutritional exposure to scFOS (maternal versus post-weaning) conditioned the consequences on the immune system. Our results highlight the role played by early prebiotic supplementation to optimize intestinal immune functionality in piglets to obtain health benefits., La nutrition périnatale joue un rôle décisif dans la primo-colonisation bactérienne et constitue un facteur important pour la maturation de l'immunité intestinale. Les fructooligosaccharides à courte chaîne (FOScc) étant des prébiotiques connus pour moduler le microbiote, notre étude a évalué les effets d’une telle supplémentation sur la fonctionnalité du système immunitaire intestinal des porcelets. Des truies ont reçu un régime supplémenté en FOScc ou non (CTRL) en fin de gestation et pendant la lactation. La maturation du système immunitaire intestinal a été évaluée à 21 jours. Au sevrage à 28 jours, la moitié des porcelets de chaque portée a reçu le régime CTRL ou FOScc pendant 4 à 7 semaines. En post-sevrage, deux challenges vaccinaux ont été effectués séparément, un premier vaccin dirigé contre la bactérie intestinale Lawsonia intracellularis et le second contre le virus respiratoire Influenza afin d’évaluer la réactivité immunitaire ultérieure. La supplémentation maternelle en FOScc a stimulé le développement du système immunitaire du porcelet allaité. Une telle amélioration a entraîné des effets bénéfiques sur sa fonctionnalité ultérieure, objectivée par un renforcement des mécanismes de défense (cellules à mucus et sécrétion de cytokines) et de la réponse vaccinale (anticorps spécifiques). La supplémentation maternelle en FOScc a amélioré la réponse immunitaire au vaccin contre L. intracellularis, mais pas celle contre le virus Influenza. La supplémentation directe en FOScc en post-sevrage n’a augmenté que la réponse vaccinale au virus Influenza. Par conséquent, la fenêtre d’exposition nutritionnelle aux FOScc (maternelle versus post-sevrage) conditionne les effets sur le système immunitaire. Nos résultats soulignent le rôle joué par la supplémentation précoce en prébiotiques pour optimiser la fonctionnalité de l’immunité intestinale des porcelets afin d’obtenir des bénéfices sur la santé.

International audience; Much U.S. swine production is in Köppen climate types classified as ‘hot-summer humid continental’ and ‘humid subtropical’. As a result, farrowing sows are often exposed to temperatures above their upper critical temperature. This heat stress (HS) can affect sow welfare and productivity and have a negative economic impact. The study objective was to evaluate the impact of a cooling pad on sows’ behavioral and heart rate responses to acute HS. Treatments were randomly allotted to 10 multiparous sows to receive a constant cool water flow of 0.00 (CONTROL, n=4), 0.25 (LOW, n=2), 0.55 (MEDIUM, n=2) or 0.85 (HIGH, n=2) L/min for 100 min and replicated eight times, switching treatments so that each sow was exposed to each treatment. The cooling was initiated 1 hour after the room reached 35°C for 100 min. Eating, drinking and nursing behaviors, postures and heart rate were recorded before heating (Period 1), prior to cooling (Period 2), and during cooling (Period 3). There were no differences between LOW, MEDIUM and HIGH flow rates for any periods on all behavioral and heart rate traits, so data were pooled (COOLED). There were no differences in any of the measures during Periods 1 and 2, except for the ratio of short term to long term heart rate variability (SD1:SD2) with higher values for CONTROL than COOLED sows in Period 2. During Period 3, CONTROL sows changed postures more frequently (11.5±1.6 vs 5.1±1.6 changes per hour), spent more time drinker-pressing/drinking (4.4±0.5 vs 1.4±0.4% of time), standing (6.6±1.7 vs 3.8±1.6% of time), sitting (10.0±1.2 vs 4.0±1.1), less time lying (83.0±1.8 vs 92.0±1.7% of time), especially lying laterally (62.0±5.6 vs 75.0±5.3% of time), than sows in all three cooling treatments (all P < 0.001). Heart rate during Period 3 was lower for COOLED sows compared to the CONTROL sows (100.2±3.4 vs 119.0±4.0 beat per min, P

Colostrum plays an essential role in ensuring the health, survival, and growth of piglets by providing energy, immunoglobulins, growth factors and many other bioactive components. Both colostrum yield and composition are highly variable among sows, yet mechanisms and factors that regulate colostrogenesis are not tully known. Unlike sow milk yield, sow colostrum yield is not highly determined by litter size and suckling intensity but is largely driven by sow-related factors. Colostrum synthesis is under hormonal control, with prolactin and progesterone concentrations prepartum having, respectively, positive and negative influences on colostrum yield. Less is known about the endocrine control of the end of colostrogenesis, which is characterized by the closure of tight junctions in the mammary epithelium and the cessation of immunoglobulin G transfer into lacteal secretions. Recent studies indicate that exogenous hormones may influence colostrogenesis. lnducing parturition by injecting prostaglandin F2alpha in combination with an oxytocin-like molecule reduced colostrum yield, and injection of prostaglandin F2alpha alone either reduced colostrum yield or had no effect. lnjecting a supraphysiological dose of oxytocin to sows in the early postpartum period delayed the tightening of mammary tight junctions, thereby prolonging the colostral phase and increasing concentrations of IGF-1, immunoglobulins G and A in early milk. The development of strategies to improve colostrum composition through maternai feeding has been largely explored whereas very few attempts were made to increase colostrum yield. This is most likely because of the difficulty in measuring colostrum yield. The fatty acid content of colostrum greatly depends on the amount of lipids provided in the sow diet during late gestation, whereas the fatty acid profile is largely influenced by the type of lipid being fed to the pregnant sow. Moreover, various ingredients that presumably have immune-modulating effects (such as fish oil and prebiotics mannan or short-chain fructo-oligosaccharides) increased concentrations of lgG, lgA and/or lgM in sow colostrum when they were provided during the last weeks of gestation. Finally, there is sorne evidence that sow nutrition during late gestation may influence colostrum yield but this clearly warrants more research.

National audience; The objective was to develop a tool to measure sow postural activity during lactation that is kept between fences in the farrowing crate. Several sensors, placed in a single metal box, were attached to the upper part of the back of sows with a custom-built belt that passes underneath the belly, just behind the front legs. For validation of the positions predicted from sensor data, sow behavior was recorded with use of a digital camera and video records were analyzed by a single observer. Prediction ability was tested with machine learning applied to random forests for the three-axis data provided by the sensors in the X, Y and Z dimensions. When comparing information provided by three sensors, i.e. two accelerometers (sensors A and B) and an application developed for a smartphone (sensor C), one sensor detected five positions more accurately than the other two. The error rate of prediction from 30% of the data was 2.1% with sensor A, 3.1% with sensor B, and 4.8% with sensor C. Additional trials focused on the ability of sensor A to distinguish among the five positions, using five sows. Statistical sensitivity was 0.94 and 0.95 for the right and left lateral positions, respectively; 0.79 for the ventral position; 0.75 for the standing position; but only 0.33 for the sitting position (because it represented only 4% of sows’ time budget). One single axis was sufficient to detect the two lateral positions. More work is necessary to better consider factors of variations among sows and optimize the sampling rate to detect the five positions accurately.

La liberté de mouvement pour les truies en maternité s’inscrit dans une démarche d’amélioration du bien-être des animaux. Les types de cases pour loger les truies et leurs porcelets sont nombreux et se distinguent par la surface nécessaire, le type de sol ou la présence d’équipements de protection des porcelets. L’expérience et les résultats expérimentaux obtenus dans les stations des Chambres d’agriculture de Bretagne et celle des Pays de la Loire depuis le début des années 2000, complétés par une revue de la bibliographie, permettent de présenter les facteurs de réussite au niveau du logement ou de la conduite des animaux. Le nombre de porcelets écrasés augmente lorsque les truies sont libres, en moyenne de 0,5 porcelet par portée après libération d’après les résultats obtenus à la station de Guernevez. Une forte variabilité est observée entre les animaux, en partie liée au comportement de la truie et à sa manière de se coucher. Le surcoût d’une maternité avec des truies en liberté est évalué à 33% par rapport à une case de contention classique, la surface nécessaire du bâtiment étant supérieure et les équipements plus robustes. Pour le bien-être des animaux, la question posée est celle de l’équilibre la liberté de mouvement de la truie et le risque d’augmentation de la mortalité de ses porcelets. Une contention sur une durée de 4 à 7 jours après la mise bas permet de limiter la mortalité des porcelets en préservant la mobilité de la truie sur le reste de la durée de lactation. Connaître les conditions de réussite techniques de l’élevage des truies libres en maternité est indispensable au moment où des initiatives commerciales ou règlementaires en Europe conduisent à son développement., Freedom of movement for sows in the farrowing building is an approach that improves animal welfare. Many types of housing pens exist for sows and their piglets, and differ according to the area required, the type of flooring and the presence of protective components for the piglets. The study and experimental results obtained since the beginning of the 2000s at stations in the Chambers of Agriculture in Brittany and the Pays de la Loire, supplemented with a literature review, describe the factors required to successfully house and manage animals. According to the results obtained on the experimental farm in Guernevez, the average number of crushed piglets increases to 0.5 piglets per litter when the sows move freely. High variability was observed among the animals, which is related to the general behaviour of the sow and its bedding behaviour. The cost of a farrowing system with freedom of movement is estimated at 33% more than a conventional crate; the required area is larger and the equipment is more robust. For animal welfare, the issue is the balance between providing freedom of movement to the sow and the risk of increased mortality for the piglets. Confining the sow in a stall for 4 to 7 days after farrowing is a way to decrease piglet mortality and maintain the mobility of the sow during the lactation period. Considering the technical conditions required for success is essential since current commercial and regulatory initiatives in Europe promote the development of loose-house farrowing systems for sows.

Nutritional requirements of lactating sows mainly depend on milk yield and greatly vary across individuals. Moreover, because the same diet is generally fed to all sows, and feed intake is low and highly variable, nutrient supplies are often insufficient to meet the requirements, especially those of primiparous sows. Conversely, sows with high appetite may be fed nutrient in excess. Acquiring data on sows and their environment at high-throughput allows the development of new precision feeding systems with the perspective of improving technical performance and reducing feeding cost and environmental impact. The objective of this study was thus to design a decision support tool that could be incorporated in automated feeding equipment. The decision support tool was developed on the basis of InraPorc® model. The optimal supply for a given sow is determined each day according to a factorial approach considering all the information available on the sow (i.e. parity, litter size, milk production, body condition…) or predicted from real-time data (i.e. expected feed intake). The approach was tested using data from 817 lactations. Precision feeding (PF) with the mixing of two diets with different nutritional values was then simulated in comparison with conventional feeding (CF) with a single diet. In sows fed in excess PF reduced average digestible lysine excess from 10.9 to 2.7 g/d, whereas in deficient sows the deficiency was reduced from -5.7 to -2.1 g/d. Overall, PF reduced average lysine intake by 6.8%. At the same time, with PF, lysine requirement was met for a higher proportion of sows, especially in younger sows, and a lower proportion of sows, especially older sows, received excessive supplies. PF also reduced average phosphorus intake while limiting the occurrence of excess and deficiency. This study confirms the potential of precision feeding in order to better achieve nutritional requirements of lactating sows and reduce their nutrient intake and excretion. This project has received funding from the European Union’s Horizon 2020 research and innovation program, grant agreement no. 633531.

Two trials were conducted at experimental stations of IFIP, located in Romillé (France, Trial 1), and INRA, located in Saint Gilles (France, Trial 2), on pregnant sows equipped with individual ear tag accelerometers to record their activity level: duration of lying, standing and moving sequences. The first trial involved 72 sows penned on a slatted floor in a dynamic group with connected drinkers and automatic feeders, whereas the second trial was carried out on 4 small groups of 6 sows penned on a concrete floor with straw and fed in individual stalls. Firstly, an algorithm was built from video recordings of 24 sows on the slatted floor (2 x 2 h sequences per sow, 96 h). Secondly, the accuracy of the algorithm was assessed by recording and sequencing 96 h and 109 h, respectively, on the slatted floor and concrete floor with straw. The respective sensitivities of the lying, standing and moving behaviours on the slatted floor were 94.4%, 66.9% and 68.4%. With straw, lower sensitivity values were found: 93.65% for lying, 68.35% for standing and 38.83% for moving, linked to more investigative behaviours using the head. The final step was to use these data to improve the feeding practices of pregnant sows, taking their activity level into account. The strong inter- and intra-individual variability shown in the physical activity is a limiting factor for detection of health problems, such as lameness, through the accelerometers. Thus we need additional information, especially the behaviour data generated by identified drinkers and automatic feeders.

During the CoreOrganicII ProPIG, animal health & welfare (AHW) of organic pigs in 3 husbandry systems (8 countries) was compared: indoor with outside run (IN: n=34 farms), outdoor on pasture (OUT: n=12) and partly outdoor with at least one age group on pasture (POUT: n=28). The hypothesis was that all systems can deliver good welfare when well managed. 7 trained observers assessed pregnant sows (SO), weaners (WE) and fatteners (FA) using animal-based parameters. Non-parametric Kruskal-Wallis tests were used, if P60% POUT, IN). Signs of diarrhoea in WE were less frequent in OUT (0%) than in IN (25.0%) and diarrhoea in FA was less frequent in OUT than in POUT and IN (0%, 0%, 8.3%). OUT had fewer lame SO than POUT and IN (0%, 3.4%, 7.1%). Across systems, prevalences of most AHW areas but respiratory problems in IN and POUT and diarrhoea in IN were low. Beyond that, OUT appeared to be beneficial with regard to several areas of AHW, which could be explained by the environmental conditions, e.g. respiratory problems (air quality), diarrhoea (exposure to faeces) and lameness (flooring). POUT farms in most cases kept SO outdoors and WE and FA similar to IN farms, and this was reflected in the results. It can be concluded, that systems do differ regarding AHW and development of organic husbandry systems across Europe should take this into account.

In the context of sow hyper-prolificacy, the amount of milk available per piglet may be limiting for piglet survival, health and growth performance, especially for the lightest piglets. Findings from an in vivo study suggested that inflammation occurring the days after farrowing had a negative impact on sow milk production in hyperprolific sows. Therefore, any feed ingredients with anti-inflammatory properties may be helpful to increase milk production and piglet performance. Recently, Scutellaria baïcalensis, a widely spread labiate in Russia, China and Japan, has been shown to increase piglet growth rate from birth to weaning. Baicalin, the major compound found in S. baïcalensis extract, is a flavone glycoside with strong antioxidant and anti-inflammatory effects. The aim of the present study was to characterize the effects of baicalin on porcine mammary epithelial cells (MEC). MEC were purified from mammary glands collected collected in sows at peak lactation and cultured in the presence of increasing concentrations of baicalin (from 0 up to 200 μg/ml). We demonstrated that baicalin stimulated MEC proliferation when added to culture media at low concentrations (+60% at 10 μg/ml, P

International audience; Recent studies indicate that feed efficiency is a key factor for both the economic and the environmental sustainability of pig production. The efficiency of energy utilization by sows and fattening pigs depends mainly on their reproductive and growth potential, and on the rate of deposition of body lipids and protein. These factors also affect the efficiency of use of protein, amino acids and minerals, and consequently their excretion. In fact, both the oversupply and the undersupply of nutrient may induce a decrease in the efficiency of nutrient use, which makes it difficult to handle in practice because of the changes in nutrient requirements over time and their variability among animals. In this context, the availability of new technologies for high throughput phenotyping of pigs and their environment, and of innovative feeders that collect information and allow the distribution of a combination of different diets, offers opportunities for a renewed implementation of prediction models of nutrient requirements, in the perspective of improving feed efficiency and reducing feeding costs and environmental impacts. The approach is to better adapt the amount and composition of the feed distributed to a group of animals or to each individual animal, according to the expected performance over the forthcoming period. The ultimate goal is to feed each individual pig, each day with an optimized tailored ration, corresponding to its expected performance. This requires (1) the real-time collection of information on animal performance and housing conditions, (2) the development of a decision support system for the determination of expected performance and nutrient requirements and (3) the mixing and the distribution by an automated feeder of the optimal ration to be fed to a given pig or a given pen. This represents a real change in the paradigm of animal nutrition for the coming years. Recent experimental studies in the literature confirm theinterest of precision feeding, as well for fattening pigs and gestating sows, with potential reductions of feeding cost and nitrogen and phosphorus excretion of up to 10 to 20%. However further technological developments may still be needed before practical implementation.

Estrus synchronization is important for optimal management of gilt reproduction in farms. Synthetic progestogens are used for this purpose, but there is growing demand for non-hormonal alternatives. Before puberty, gilts exhibit a “waiting period”, related to ovarian development and gonadotrophin secretions, during which external stimulation, such as boar exposure, could induce and synchronize first ovulation. Practical non-invasive tools for identification of this period in farms are lacking. During this period, urinary estrone levels are high, but urine sampling is difficult in group-housed females. Our aim was to search for steroidal biomarkers of this “waiting period” from immature to pubertal gilts through saliva monitoring. Six 144-to 147-day-old Large White gilts were subjected to ultrasound puberty diagnosis 3 times a week until first ovulation. Urine and saliva samples were collected at the same frequency for estrone assay and steroidome analysis respectively. Data were analyzed using the R software (nonparametric permutation test). Urinary estrone concentration significantly increased 2 weeks before puberty (detected at 182–192 days). Steroidome analysis quantified 28 steroids in saliva. Significant variations were detected within 2 weeks before puberty for dehydroepiandrosterone (decrease) and estradiol-17b (increase). These steroids could be biomarkers of the “waiting period”. These results confirm that non-invasive salivary sampling could allow the identification of the physiological status of the gilts and presumably the optimal time for application of the boar effect.

The objectives were to evaluate quantitative animal-based measures of sow welfare (lameness, oral stereotypies and reactivity to humans) under commercial farm conditions, and to estimate the influence of housing, sow parity and stage of gestation on the outcome of these measures. Across 10 farms, 311 sows were used. Farms differed in terms of housing design (pen v. stall), space allowance, floor type in stalls (partially v. fully slatted), and feeding system in pens (floor v. trough). Lameness was assessed in terms of gait score, walking speed, stride length, stepping behaviour, response to a stand-up test and latency to lie down after feeding. The presence of oral stereotypies and saliva foam were recorded. Reactivity to humans was assessed by approach (attempt to touch the sow between the ears) and handling tests (exit of the stall for stall-housed sows, or isolation of the animal for pen-housed sows). Only stride length and walking speed were associated with lameness in stall-housed sows (P

The development of housing for farrowing and lactation to ensure the welfare of the sow and piglets whileremaining economically efficient, and therefore the sustainability of the farm, is a challenge in swine production. Experimental studies were conducted on alternative systems combining the enhancement of the sow’s living area and its freedom with an assessment of performance, particularly neonatal survival (Baxter et al., 2012). A process of innovation has been developed inspired by the "innovative design" method based on the C‐K (Concept‐Knowledge) theory, to propose prototypes of alternative systems of housing for birthing and lactating sows. The first stage focuses on three methods used according to people’s level of knowledge of the subject: 1/“Advanced Systematic Inventive Thinking” (basic), 2/ brainstorming (limited level), 3/ direct and telephone interview (experts). This stage allowed for an abundance of ideas concerning the concepts of ‘forced freedom’, ‘stalls’, ‘sow’, ‘farrowing/lactation’, and the emergence of a variety of viewpoints within focus groups (geneticists, ethologists, ergonomists, doctors, veterinary, citizens, students...). Fifteen concepts of innovative maternity thus arose, integrating four basic principles: maintaining the mother‐offspring relationship, protecting the young, enhancement of the living area, separate living areas for the sow and its litter (Engineers report 2013). The second stage of the project focused on the assessment of four scenarios of housing within the four basic principles, with a view to developing a breeding room to conduct experiments. For each scenario we evaluated the technical feasibility and the possibilities of scientific programmes related to feeding and social behaviour (maternal, human‐animal relations), excretory behaviour, needs and use of surfaces by animals. A scenario was identified to respond to the research goals, the device consisting of five stalls of 10 m2 on straw flooring, equipped with a feeding device for the sow and a piglet nest. The sows have access to a common feeding area equipped with an automatic concentrate distributor and access to outside the building. The entire system is based on precision farming tools (computerized food distributor, accelerometers for physical activity, videotracking,...).; Le développement de logements pendant la phase de mise‐bas et la lactation pour assurer le bien‐être de la truie et des porcelets tout en maintenant une efficacité économique, et donc la durabilité de l’élevage, est unchallenge en production porcine. Des études expérimentales ont été menées sur des systèmes alternatifscombinant l’enrichissement du milieu de vie et la liberté de la truie, avec une évaluation des performances, enparticulier la survie néonatale (Baxter et al, 2012). Une démarche d’innovation a été développée en s'inspirantde la méthode de "conception innovante" basée sur la théorie C‐K (Concept‐Knowledge), pour proposer desprototypes de systèmes alternatifs de logement des truies parturientes et allaitantes. La première étape s’estappuyée sur trois méthodes utilisées en fonction du niveau de connaissance des personnes sur le sujet : 1/“Advance Systematic Inventive Thinking” (naïfs), 2/ brainstorming (niveau limité), 3/ interview téléphoniqued’experts ? Cette étape a permis un foisonnement d’idées autour des concepts de «liberté contrainte»,«logement », « truie », « mise‐bas/lactation », et l’émergence d’une diversité de points de vue au sein de groupes focus (généticiens, éthologistes, ergonomistes, docteurs, vétérinaires, citoyens, étudiants…). Quinze concepts de maternité innovante ont ainsi émergé, intégrant quatre principes de base : maintien de la relation mère‐jeune, protection des jeunes, enrichissement du milieu de vie, zones de vie distinctes pour la truie et sa portée (rapport Ingénieurs 2013). La seconde étape du projet a porté sur l’évaluation de quatre scénarios de logement respectant les quatre principes de base, avec la perspective d’un aménagement d’une salle d’élevage pour la conduite d’expérimentations. Pour chacun des scénarios, ont été évaluées la faisabilité technique et les possibilités de programmes scientifiques relatifs au comportement alimentaire et social (maternel, relation homme‐animal), au comportement d’excrétion, aux besoins et l’utilisation des surfaces par les animaux. Un scénario a été identifié pour répondre aux objectifs de recherche, le dispositif consistant en cinq loges de 10 m2 sur sol paillé, équipées d’un dispositif alimentaire pour la truie et d’un nid à porcelet. Les truies ont un accès à une zone alimentaire commune équipée d’un Distributeur Automatique de Concentré ainsi qu’un accès à l’extérieur du bâtiment. L’ensemble du dispositif s’appuie sur les outils de l’élevage de précision (distributeur alimentaire informatisé, accéléromètres pour l’activité physique, videotracking,…).

Synchronizing oestrus in gilts is an important tool for pig producers to optimize the management of reproduction. Synthetic progestogens are used routinely in pig farms for this purpose, but there is a need for alternative non-hormonal breeding tools. Before puberty, gilts exhibit a “waiting period”, related to ovarian development and gonadotrophin secretions, during which an external stimulation, such as boar exposure, could induce and synchronize the first ovulation. Our aim was to characterize this “waiting period” and search for biomarkers of this period using non-invasive tools. During this period, an increase of urinary oestrone concentration has been observed, but urinary sampling is difficult in group-housed females. Salivary samples are non-invasive and easier to perform. Thus, the aim of this study was to evaluate steroid concentrations in the saliva of immature to pubertal gilts in order to search for biomarkers of the “waiting period”. Trans-abdominal ultrasonographies were performed over a period of 5 weeks on six 140-day-old Large White gilts until puberty detection. Urinary samples were collected for oestrone assay to detect the “waiting period”. Salivary samples were collected for steroidome analysis using gas chromatography coupled with tandem mass spectrometry to detect potential biomarkers of the “waiting period”. Urinary oestrone concentration increased 2 weeks before puberty. Steroidome analysis allowed the quantification of 28 steroids, 13 of them showing significant differences between weeks. Dehydroepiandrosterone concentrations decreased and estradiol-17 concentrations increased significantly just before the “waiting period”. These steroids could be biomarkers of this period. Present results confirm that non-invasive salivary samples could allow the identification of the physiological status of the gilts and the optimal time for application of the boar effect.

The potential impacts of injecting oxytocin (OXY) to sows in the early postpartum period on the quality of mammary tight junctions, milk composition, and immune status of sows and piglets were studied. Postparturient sows received i.m. injections of either saline (control [CTL]; n = 10) or 75 IU of OXY (n = 10). Injections were given twice daily (0800 and 1630 h) starting on d 2 of lactation (i.e., between 12 and 20 h after birth of the last piglet), totaling 4 injections. Milk samples were obtained before the first injection (d 2 morning [AM]), before the second injection (d 2 afternoon [PM]), and on d 4 PM and d 5 PM. Blood samples were obtained from sows before milking on d 2 AM, d 2 PM, and d 5 PM. On d 5 of lactation, a blood sample was obtained from 3 piglets per litter. Circulating concentrations of prolactin, IGF-I, lactose, and IgA in sows did not differ between treatments at any time (P > 0.10), but OXY sows had less IgG than CTL sows (P < 0.01) on d 2 PM before the second OXY injection. There were differences in milk composition on d 2 PM, with OXY sows having more IGF-I (P < 0.01), solids (P < 0.05), protein (P < 0.01), energy (P < 0.05), and IgA (P < 0.01) and a greater Na:K ratio (P < 0.01) than CTL sows. These differences were not seen in the next 2 milk samples, except for protein and IgA that still tended (P < 0.10) to be greater in OXY vs. CTL sows on d 4 PM (for protein) and on d 5 PM (for IgA) after the last injection. Milk lactose content was lower in OXY vs. CTL sows on d 5 PM (P < 0.01). Values for immunoglobulin immunocrit, IgG, IgA, and IGF-I in piglet blood did not differ between treatments (P > 0.10). Injecting OXY to sows in the early postpartum period increased leakiness of the mammary tight junctions, improved composition of early milk, and may potentially affect immune status of neonatal piglets.

Nutritional studies indicate that nutrient requirements for pregnancy differ largely among sows and according to the stage of pregnancy, whereas in practice the same diet is generally fed to all sows in a given herd. In this context, the availability of new technologies for high throughput phenotyping of sows and their environment, and of innovative feeders that allow the distribution of different diets, offers opportunities for a renewed and practical implementation of prediction models of nutrient requirements, in the perspective of improving feed efficiency and reducing feeding costs and environmental impacts. The objective of this study was thus to design a decision support tool that could be incorporated in automated feeding equipment. The decision support tool was developed on the basis of InraPorc® model. The optimal supply for a given sow is determined each day according to a factorial approach considering all the information available on the sow: genotype, parity, expected prolificacy, gestation stage, body condition (i.e. weight and backfat thickness), activity, and housing (i.e. type of floor and ambient temperature). The approach was tested using data from 2,500 pregnancies on 540 sows. Energy supply was calculated for each sow to achieve, at farrowing, a target body weight established based on parity, age at mating and backfat thickness (18 mm). Precision feeding (PF) with the mixing of two diets was then simulated in comparison with conventional (CF) feeding with a single diet. Compared to CF, PF reduced protein and amino acid intake, N excretion and feeding costs. At the same time, with PF, amino acid requirements were met for a higher proportion of sows, especially in younger sows, and a lower proportion of sows, especially older sows, received excessive supplies. This study is part of the Feed-a-Gene project and received funding from the European Union’s H2020 program under grant agreement no. 633531. The data used for the simulations were issued from a project conducted within the AgriInnovation Program from Agriculture and Agri-food Canada.[br/]

Different housing systems can be used in pig production and little is known about their effect on gut microbiota composition. In this study we characterized fecal microbiota by sequencing the rRNA genes in sows kept during gestation in conventional pens with a slatted floor and in enriched pens with a floor covered with deep straw. After farrowing, microbiota of 1- and 4-day-old piglets were also monitored. Microbiota of sows from the enriched system contained significantly more Prevotella, Parabacteroides, CF231, Phascolarctobacterium, Fibrobacter, Anaerovibrio and YRC22 and significantly less Lactobacillus, Bulleidia, Lachnospira, Dorea, Ruminococcus and Oscillospira than microbiota of sows from the conventional system. The Firmicutes to Bacteroidetes ratio was 0.96 in the microbiota of sows kept in the enriched pens and this increased to 1.66 in the microbiota of sows kept in the conventional system. The production system therefore influenced microbiota composition, most likely due the ingestion of the straw. The microbiota of 1- and 4-day-old piglets differed from the microbiota of sows and sows therefore did not represent the most important source for their colonization in early days of life.