La relation des porcs aux humains en élevage : bases biologiques et impact des pratiques

Synthèse.The relationship between pigs and humans is at the heart of animal husbandry and is one of the pillars of the animal welfare issue. Indeed, humans, through their behaviour and their choices of practices, housing conditions and herd management, influence the mental state of their animals. This article aims to review the work in the field of pig farming. We first describe the impact of farming practices and management systems on the relationship between pigs and humans. Experiments have shown that many practices cause pain, anxiety and subsequent reactions of fear in piglets towards humans, even unknown ones. Other practices can be stressful (sorting) or positive (feeding) for animals. “Relational” practices, in the sense of practices aimed at developing a close relationship, reduce fear. We then describe impacts of categories of human interactions (auditory, visual, tactile) on pig behaviour. Human presence, at a rate of a few minutes per day, is sufficient to get a piglet used to humans. Talking to animals is essential, and has an impact even in utero. Piglets appreciate soft tactile contacts, caresses and scratches. Human presence, combined with positive interactions, thus gains a positive value, which creates a climate of trust and stimulates positive emotions that will improve animal welfare. Finally, we discuss the importance of considering pig behaviour to create a good relationship in pig farming and to train and give advice to farmers. Stimulating a good relationship (fearless and confident) will not only promote the welfare of pigs but also secure the work of farmers and improve their job satisfaction.La relation entre les porcs et les humains est au centre de l’élevage et est aujourd’hui un des piliers de la question du bien-être animal. En effet, l’humain, par son comportement et par ses choix de pratiques, de conditions de logement et de gestion du troupeau va influencer l’état mental de ses animaux. Cette synthèse se propose de faire le bilan des travaux sur la relation humain-animal dans le domaine de l’élevage porcin. Nous décrivons tout d’abord l’impact des pratiques et des modes d’élevage sur la relation à l’humain. Des expérimentations ont montré que certaines pratiques sont source de douleur et d’angoisse pour les porcelets, et provoquent des réactions ultérieures de peur vis-à-vis des humains, même inconnus. D’autres pratiques peuvent être stressantes (tri) ou positives (alimentation) pour les animaux. Des pratiques dites relationnelles, au sens de pratiques ayant pour but de développer une relation de proximité, vont diminuer la peur des humains et favoriser une relation de confiance. Nous décrivons ensuite l’impact des différentes catégories d’interactions humaines (auditives, visuelles, tactiles) sur le comportement des porcs. La présence humaine suffit à habituer un porcelet aux humains, à raison de quelques minutes par jour. Parler aux animaux est primordial, et a un impact même in utero. Les porcelets apprécient les contacts tactiles doux, caresses ou grattages. L’humain, associé à des interactions positives, va ainsi prendre une valeur positive, ce qui permettra d’instaurer un climat de confiance et pourra susciter des émotions positives favorables au bien-être animal. Finalement, nous discutons de l’importance de prendre en compte le comportement des porcs pour créer une bonne relation en élevage, et de la prise en compte de l’impact de la relation dans la formation et le conseil aux éleveurs. Favoriser une bonne relation (sans peur et en confiance) sera bénéfique non seulement pour le bien-être des porcs, mais aussi pour la sécurité et la satisfaction au travail des éleveurs

Review. Divergent selection for residual feed intake in the growing pig

To view supplementary material for this article, please visit https:/doi.org/10.1017/S175173111600286XThis review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant ( P<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses wereobserved on growth rate (−12.8 g/day, P <0.05) and body composition (+0.9mm backfat thickness, P = 0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat ( P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors,via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory

A co-elaborative tool to assess growing pigs welfare

Animal welfare assessment systems are mainly used by external auditors. Better commitment could be achieved if farmers could assess the welfare of their pigs themselves and act to improve it. A project was designed to build an animal welfare assessment tool with farmers from three different French regions. An exhaustive list of criteria was established at three co-design workshops involving farmers, their advisers and animal welfare experts. Farmers indicated how they evaluated whether their animals were doing well, either spontaneously in a brainstorming discussion, or by answering to questions from a naïve visitor. Then representatives of the groups gathered, prioritized and selected the criteria according to four dimensions: housing (cleanliness, moisture, resting posture), behaviour (fear of human, use of enrichment material),health (diarrhoea, coughing, lameness, severe body/tail lesions, physical appearance) and feeding (trough/drinker cleanliness, low body weight). They proposed rapid measurement methods (observation at group level from the corridor and individually in the pen) and stages to use them: two rooms in the post weaning period (PW) and two rooms in the growingfinishing period (G). A prototype tool was built on these bases. Farmers and advisers scored their animals twice, after the training session and six months later (spring 2017). The first series of evaluation indicated that lameness frequency was lower in PW than in G (0.27 vs 0.41% of pigs) and ranged from 0 to 1.7% (PW) and 3.6% (G). Exploratory behaviour was scored whenentering the room and 10 minutes later. The percentage of pens with enrichment investigation was higher after 10 minutes presence, higher in PW period than in G period (34.5 vs 23.1%) and ranged from 0 to 100% of pens. The feedback of both sessions will allow to assess the feasibility of this tool in different type of farms, the difficulties encountered in the implementation by the farmers and to finalize with them a list of relevant measures

Neurobiologie du comportement alimentaire : le modèle porcin en neurosciences comportementales appliquées à l’alimentation et à la santé humaines

Dossier : Neurobiologie des fonctions et des comportementsThe pig is an excellent model to study human eating behaviour and its neurobiological determinants. The pig is omnivorous and hasa digestive system that closely resembles that of humans. Furthermore, the establishment of eating behaviour and food preferencesin the pig follows the same rules and influences as those identified in humans. It is thus possible to observe similar behaviouralresponses related to food in both species, like for instance spontaneous attractions for certain basic flavours, or the development ofpreferences that have been conditioned or learned through individual experiences or signals perceived in the environment or transmittedby the mother. In addition, the brain of pigs and humans shares common developmental, anatomical and functional features, thusenabling precise explorations via the use of modern techniques of brain functional imaging. The neurobiological mechanisms underlyingthe development of food preferences or aversions have been described in the pig model, as well as some neurocognitive abnormalitiesassociated with obesity or the chronic consumption of deleterious diets. Therefore, the pig can be used as a pertinent model to explorenew therapies, such as vagus nerve stimulation or deep brain stimulation, to fight against obesity and eating disorders. The pig modelthus offers many opportunities for exploratory and preclinical biomedical research in the field of food and nutritional neurosciences.Le porc représente un excellent modèle pour étudier le comportement alimentaire humain et ses déterminants neurobiologiques. Outre le fait que le porc soit un omnivore et que son système digestif soit particulièrement proche du nôtre, la mise en place de son comportement et de ses préférences alimentaires obéit aux mêmes règles et influences que celles identifiées chez l’Homme. Il est ainsi possible de décrire des parallèles au niveau des attractions spontanées pour certaines saveurs fondamentales, de la mise en place de préférences conditionnées ou apprises grâce aux expériences individuelles, mais aussi aux signaux perçus dans l’environnement ou transmis par la mère. Le porc possède également un cerveau particulièrement proche de celui des primates, ce qui permet des explorations précises grâce aux outils modernes de l’imagerie fonctionnelle cérébrale. Les mécanismes neurobiologiques sous-tendant la mise en place de préférences ou d’aversions alimentaires ont été décrits chez le modèle porcin, tout comme certaines anomalies neurocognitives associées à l’obésité ou à la consommation chronique de régimes délétères. Le porc peut ainsi être utilisé comme un modèle privilégié pour explorer de nouvelles thérapies pour lutter contre l’obésité et les troubles du comportement alimentaire, telles que la stimulation du nerf vague ou la stimulation intracérébrale profonde. C’est tout un champ exploratoire et préclinique que le modèle porcin permet d’ouvrir en recherche biomédicale, dans le domaine des neurosciences appliquées à l’alimentation et à la nutrition

Purification des eaux polluées par du phénol dans un pertracteur à disques tournants

Ce travail se situe dans le cadre des recherches du laboratoire sur un procédé d extraction et desextraction, qui implique trois phases liquides, deux phases aqueuses et une phase organique. La faisabilité d un tel procédé passe par le choix de la phase organique et par l étude des équilibres mis en jeu lors du processus d extraction.Le principal objectif concerne : la récupération et la concentration de phénol contenu dans une solution aqueuse, en utilisant un pertracteur à disques tournants alternatifs en régime batch, semi-batch et continu. Par un mécanisme du transfert de matière entre les phases, le phénol passe de la phase aqueuse d alimentation vers la phase organique puis de la phase organique vers la phase aqueuse réceptrice.La faisabilité de la méthode est testée en mode fermé. Nous étudions l influence de certains paramètres : tels que la concentration du phénol, la variation de pH de la phase d alimentation, la vitesse de rotation des disques et le volume de la phase organique, sur l évolution du transfert du phénol entre les phases. Une solution aqueuse à pH 2, ayant une concentration en phénol égale à 50, 100 ou 300 mg.L-1, est mise en contact avec de l huile de colza, qui est elle-même en contact avec une solution aqueuse à pH 13. Les résultats montrent qu au bout de six heures de fonctionnement, 70% à 99% du phénol contenu initialement dans la solution aqueuse à pH 2, se trouve dans la phase aqueuse à pH 13.Afin de récupérer et de concentrer le phénol dans la phase réceptrice, nous avons réalisé des expériences dans le pertracteur fonctionnant en mode semi-ouvert et en mode ouvert.En système semi-ouvert, l influence de trois paramètres est étudiée : la concentration initiale de phénol, la vitesse de rotation des disques et le débit de la phase d alimentation. En système ouvert, seul l influence du débit à la phase aqueuse est analysée. Enfin, grâce à la modélisation basée sur la théorie du double film, nous avons estimé l ordre de grandeur des coefficients de transferts de matière partiels pour différentes vitesses de rotation en système fermé.This work is focused on a pertraction process, coupling extraction and stripping steps in the same apparatus and involving three liquid phases, two aqueous phases and one organic phase. The process feasibility requires the choice of a appropriate organic phase (membrane) and a phase equilibria studies.The main objective was recovery and concentration of phenol contained in dilute aqueous solutions using a rotating discs pertractor in batch, semi-batch and continuous mode. The phenol is transferred from the feed phase (aqueous phase) through the membrane (organic phase) in the receiving phase (aqueous phase).The feasibility of the method is tested in a batch system. We studied the influence of some parameters such as the phenol concentration, the feed pH, the discs rotational speed and the volume of the organic phase. An aqueous solution at pH 2 (feed) with a phenol concentration equal to 50, 100 and 300 mg.L-1, is placed in contact with rapeseed oil (liquid membrane), that is itself in contact with an aqueous solution at pH 13 (receiving phase). The obtained results show that after 6 hours, 70% to 99% of phenol initially contained in the aqueous solution at pH 2, is transferred in the aqueous phase at pH 13.To concentrate phenol in the receiving phase, we performed experiments in semi-batch and continuous mode.In semi-batch system, the influence of three parameters is studied: the feed concentration, the discs rotation speed and the feed flowrate. In open system, (continuous mode), only the influence of the aqueous phases flowrates is analyzed.Finally, using mass transfer model based on a double film theory, we estimate the partial mass transfer coefficients for three phases at different rotation speeds in batch system.ROUEN-INSA Madrillet (765752301) / SudocSudocFranceF

Socio-economic and broader impact

Socio-economic and broader impact. Lauriers de l'INR

La relation mère-jeune chez les porcins : de la naissance au sevrage

L’élevage intensif du porc impose des contraintes qui peuvent être néfastes à son bien-être. Chez le sanglier ou le porc domestique en conditions semi-naturelles, la femelle parturiente vit en groupe matriarcal et confectionne un nid destiné à dissimuler et protéger les jeunes. Un lien s’établit entre la truie et ses porcelets et la période d’allaitement dure au minimum 10 à 12 semaines. Les conduites d’élevage actuelles ont fondamentalement modifié le mode de vie du porc. Les truies sont généralement placées en cases individuelles et ne peuvent confectionner un nid. Pendant toute la durée de l’allaitement, les contacts avec les porcelets sont réduits au minimum et initiés par ces derniers. Il existe néanmoins des échanges vocaux et olfactifs facilitant la localisation des tétines et conduisant à une reconnaissance réciproque mère-jeunes, effective dans les 48 heures. L’absorption rapide de colostrum est essentielle pour la protection immunitaire et l’apport énergétique. Le rythme des allaitements est d’environ 1 par heure pendant les premières semaines de lactation, avant de diminuer progressivement. Les porcelets développent rapidement une grande fidélité aux tétines, à l’issue de combats souvent intenses. Le lien mère-jeunes n’est pas aussi sélectif que chez les ruminants et des adoptions sont facilement réalisables lorsque les porcelets sont âgés de moins de trois jours. Ultérieurement, l’adoption de quelques porcelets devient difficile et ceux-ci tardent à s’engager à la tétée. Cependant, la substitution d’une portée entière est facilement acceptée par la truie, même après 3 semaines d’allaitement. Le sevrage, interdit en deçà de 4 semaines sauf dans les élevages en bandes, est réalisé à cet âge dans la majorité des élevages intensifs. Il peut être pratiqué dès que les porcelets sont âgés d’une semaine, mais uniquement si leur survie est en jeu. Les perturbations comportementales et zootechniques sont d’autant plus négatives que le sevrage est précoce. La prise en compte du bien-être de l’animal impose des précautions visant à ne pas placer l’animal dans une situation de peur ou d’anxiété et à lui permettre d’exprimer les comportements dits normaux de l’espèce.Modern production methods can induce negative consequences for pig welfare. In wild-pigs, as in domes,tic pigs reared in natural conditions, parturient females live in a matriarchal group and build a nest to protect their piglets. A selective bond is established between sows and piglets, and suckling continues for a minimum of 10 to 12 weeks. Present rearing conditions have largely modified the life of pigs. Generally, sows are kept in individual pens and can not build a nest. During the suckling period, contacts between the sows and piglets are reduced and only initiated by the young. However, vocal and olfactive exchanges help piglets localise the teats and induce a reciprocal recognition between mother and young during the first 48 hours post partum. The absorption of colostrum as soon as possible after birth is essential for immunity protection and nutrition. The rate of suckling is approximately once per hour during the first weeks of lactation, then it decreases progressively. During the first days post partum, piglets develop a preference for the teats after intensive rights. The attachment between mother and young is not as selective as in ruminating animals. Fostering of piglets is easy when they are less than three days old. Later, adoptive sows accept foreign piglets with difficulty and the young do not attempt to suck for the first hours, or even days. However, the substitution of an entire litter is easily accepted by the sow, even after 3 weeks of nursing. In most cases piglets am weaned at 4 weeks, Weaning before that time is not permitted in intensive breeding, unless health reasons require that the piglets be weaned when they are only one week old. Behavioural and zootechnical disturbances appear correlated with the precocity of weaning. In modern husbandry, the welfare of animals is respected and an attempt is made to avoid anxiety-producing situations and to permit normal behaviour of the species

Animal based indicators as tools to study production disease in pigs

International audienceThe incidence and severity of production diseases (PD) are influenced by environmental conditions and animal predisposition. The control of PD requires the identification of risk and predisposing factors at several levels from epidemiological to infra animal studies. The identification of pigs affected by diseases, and at risk to be, is one of the objectives of the PROHEALTH project. Firstly, we present the results of a literature review aiming at identifying animal-based traits characterizing the physiological and health status of pigs. Those traits are potential indicators of diseases. This review aimed also at quantifying the influence of factors relating to animal or husbandry practices on these traits. In a second time, pigs were experimentally challenged to enhance the risk of leg, digestive and respiratory diseases and some of these indicators were used to evaluate animal health status. The literature analysis showed that indicators relating to performance characteristics or immunological response are potential tools to prognosis diseases. Accordingly, experimental studies showed that immune indicators such as acute phase proteins are associated with depressed growth performance and feed efficiency in challenged pigs. The influence of genetic background and sex was not evaluated by the meta-analysis, this information often lacking in the literature. Yet, experimental trials clearly revealed that different lines of pigs (French Large White or Finish Landrace) had different susceptibility of lameness and osteochondrosis, respiratory and inflammatory disorders, and digestive disorders at weaning. Moreover, osteochondrosis lesions were more severe in boars than in gilts. Altogether our results showed that some of these indicators could help to identify production diseases or to test practice limiting the disease. This work has received funding from the EU-FP7 PROHEALTH project (grant agreement no. 613574)

Effect of genetic selection and physical activity on lameness and osteochondrosis prevalence in pigs

Presented at 16. International Conference on Production Diseases in Farm Animals (ICPD), Wageningen, NLD (2016-06-21 - 2016-06-23). Wageningen, NL

Leukemic plasmacytoid dendritic cells share phenotypic and functional features with their normal counterparts.

This work aims to further characterize the newly described leukemic plasmacytoid dendritic cells (LPDC), for which we had previously demonstrated their normal, PDC-like ability to produce IFN-alpha. In addition, LPDC also express the specific antigens BDCA-2 and BDCA-4. Importantly, they become fully competent antigen-presenting cells (APC) after a short maturation induced by IL-3 + CD40L or virus, exhibiting a characteristic APC phenotype (high expression of CD83 and of the costimulatory molecules CD40, CD80, CD86). Whereas IL-3 + CD40L-activated LPDC prime naive CD4(+) T cells towards a Th2 pathway (IL-4-secreting T cells), virus-activated LPDC drive a Th1 profile (IFN-gamma-secreting T cells). Moreover, we show in one case that LPDC are able to capture, process and present exogenous antigens, leading to the activation of both CD4(+) and CD8(+) T cell clones in an antigen-specific manner. This study further characterizes the phenotype and immunological functions of LPDC