Search

La question des émotions des animaux d’élevage s’inscrit dans la volonté d’améliorer les conditions d’élevage en prenant en compte leur bien-être. La genèse des émotions repose sur la capacité cognitive des individus à percevoir, évaluer et réagir à leur environnement. La capacité de perception met en jeu différentes sensorialités et participe à la reconnaissance des éléments de l’environnement de l’animal sans nécessairement déclencher d’émotions. Les situations déclenchantes d’émotion les plus étudiées chez les animaux d’élevage sont la nouveauté, la séparation sociale ou la présence d’un être humain. De plus, les réactions émotionnelles, évaluées par les réponses comportementales, endocriniennes et neurovégétatives sont modulées par le genre, l’état physiologique ou certaines hormones comme la mélatonine. Les structures cérébrales du réseau neuronal des émotions sont impliquées dans la perception et le traitement des informations de l’environnement, et/ou dans l’expression des réponses émotionnelles. Chez les animaux d’élevage, les structures cérébrales les plus étudiées sont le système olfactif pour la perception, le cortex frontal et l’amygdale pour le traitement des informations, le noyau paraventriculaire de l’hypothalamus pour les réponses endocriniennes. D’autres travaux suggèrent le rôle potentiel de structures du tronc cérébral dans les réponses neurovégétatives et de la substance grise périaqueducale dans les réponses comportementales et plus largement dans les stratégies d’adaptation. En perspective, il est maintenant nécessaire d’étudier l’impact de l’expérience précoce sur le développement du réseau neuronal des émotions et de mieux comprendre la part de l’évaluation cognitive dans la genèse des émotions.

International audience; Olfactory cues of individuals of the same species or from different species may induce changes in behaviors and physiological reactions in mammals. However, there are few studies on the influence of human odor on animal behavior and welfare, especially those of rodents and farm animals. The present study aimed to investigate whether the odor of a stressed human (in sweat) would modify the behavior of mice and cows. We hypothesized that laboratory and farm animals can perceive human emotions though olfactory cues and that human emotional chemosignals can modify their behavioral reactions and welfare. Two odors of human axillary sweat were collected from engineering students (n = 25, 14 females and 11 males; 21.1 ± 0.7 years old, range: 19-23 years old): a "stress" odor collected after an exam and a "non-stress" odor collected after a standard class. Two experiments were then conducted to test the discrimination of these two odors by male mice (n = 20) under standard conditions and by cows (n = 10) under farm conditions. During the experiments, the behavioral responses of the animals to both odors (through a dispenser for the mice and a bucket for the cows) were observed. The mice produced significantly (p = 0.004) more fecal pellets with the stress odor dispenser than with the non-stress-odor dispenser. The cows spent significantly (p = 0.04) more time smelling the non-stress-odor bucket than control. For both species, the other behaviors observed did not differ significantly between the odors. Mice and cows seemed to perceive and react to stressful human chemosignals. Mice showed physiological reactions that indicated stress in response to the stress odor of humans, while cows showed preference reactions in response to the non-stress odor of humans. This preliminary study showed that laboratory and farm animals, such as male mice and cows, seemed to discriminate certain odors emitted by humans that were likely related to different emotions. Animals may recognize stressful human chemosignals, associate these signals with negative husbandry practices or human-animal relationships, and consequently modify their behavior.

International audience; Bird damage, from sowing to crop establishment, is an important issue for farmers in many parts of the world. However, reliable and cost-effective solutions remain elusive because management tools and research on the subject are limited. The spatial variability of damage across landscapes and the adaptative behaviour of birds create further challenges. Additionally, the issue must be tackled at the landscape scale and involve a variety of stakeholders with conflicting interests and objectives. We summarize some of the challenges and opportunities identified to face these difficulties and address four major research directions for operational solutions including 1) crop damage assessment, 2) methods and tools development at the landscape scale, 3) coordination of stakeholders, and 4) pest bird ecology in agroecosystems. More fundamentally, we address the question of largescale ecological dynamics that can explain changing damage patterns such as the recent observations of increased damage in Europe. Despite the impact to the agricultural sector, research effort to understand vertebrate pest damage is still modest. We advocate for the creation of networks to share knowledge and feedback and engages multiple stakeholders, including ecological and agricultural researchers, farmers, and policy makers.

International audience; The bidirectional communication between the central and the enteric nervous system named the gut-brain axis has been widely recognized. The gut microbiota has been implicated in a variety of stress-related conditions including anxiety, depression and irritable bowel syndrome based on rodent studies or correlative analysis in human patients. The aim of the present study was to investigate to what extent changes in behavior during stressful events and in the microbial composition of the colonic ecosystem were associated in horses. The microbiota alterations were induced by a change from a high-fiber diet (100% hay, H diet) to a progressive low-fiber and high-starch diet (56% hay and 44% barley, HB diet) on six fistulated horses. Colonic total anaerobic, cellulolytic, amylolytic and lactate-utilizing bacteria were enumerated once on H diet and once on HB diet. Bacterial richness, diversity and structure at family and genus level were also determined. The behavior of horses was assessed through two standardized stressful tests: a novelty test and an umbrella test. The different alterations measured in the colonic microbiota demonstrated a lower fibrolytic capacity and a higher amylolytic capacity of the ecosystem when horses received HB compared to H diet. During the novelty test, the frequency of blowing was significantly higher in HB than in H diet and was positively correlated with the concentration of amylolytic bacteria and the Succinivibrionaceae relative abundance. During the umbrella test, behavioral variables were not significantly different between the diets but the colonic content pH was negatively correlated with the frequency of startle response. Behavioral responses of anxiety were related to hindgut microbiota indicators of a high-starch diet. Dietary-induced modulation of the gut microbiota composition may have changed the horses' behavioral reactions in stressful situations.

International audience; This study investigated the relationships between four behavioral and postural indicators of a compromised welfare state in loose boxes (stereotypies, aggressive behaviors toward humans, withdrawn posture reflecting unresponsiveness to the environment, and alert posture indicating hypervigilance) and the way horses perceived riding. This perception was inferred using a survey completed by the usual riding instructor and during a standardized riding session (assessment of behaviors and postures, qualitative behavior assessment (QBA) and characterization of the horses' locomotion using an inertial measurement unit). In accordance with ear and tail positions and the QBA, stereotypic and the most hypervigilant horses in loose boxes seemed to experience a more negative affective state during the riding session compared with nonstereotypic and less hypervigilant animals (P < .02 in all cases). Horses which were aggressive toward humans in loose boxes had higher scores regarding the occurrence of discomfort and defensive behaviors on the survey than nonaggressive horses (P = .03). They also presented higher dorsoventral accelerations at a canter during the riding session (P = .03), requiring the rider to increase his spinal movement (P = .005). These results suggest that aggressive horses may be harder to ride than nonaggressive animals. The expression of unresponsiveness to the environment in loose boxes was related to more reluctance to move forward, as assessed in the survey (P = .006). This study suggests that a compromised welfare state in the stable is related to horses having a more negative perception of riding. This perception could vary depending on the expression of poor welfare.

International audience; The human-animal relationship is a key component of human and farm-animal welfare. Farm surveys, particularly for pig, dairy cattle and veal calf production, which include regular human contact, showed that animals may face aversive handling during daily work routines, which can significantly increase their fear of humans. Similar surveys of stockperson behavior towards suckling beef cattle, which are handled less often, are rare. The aim of this preliminary study was therefore to develop a tool for assessing stockperson behavior during the occasional but common weighing procedure on commercial beef farms and then to test its potential to indicate the general human-animal relationship on such farms. Two hundred and thirty interaction sequences of stockpeople handling calves on six farms were filmed during weight monitoring. During them, stockpeople’s vocal and tactile interactions and locomotion were recorded in detail. Additionally, an avoidance test with an unfamiliar human was performed with the farm’s heifers on pasture. Multiple correspondence analysis followed by ascendant hierarchical clustering (AHC) was performed on the sequences to identify groups of practices that stockpeople used during handling. Next, the relationship between the AHC groups according to the time spent weighing and the number of calf vocalizations was analyzed using one-way analyses of variance followed by pairwise comparisons (with Bonferroni correction). Three AHC groups of handling styles that including positive and negative features were identified: (1) mostly “negative” practices (67 sequences) such as hitting calves, twisting their tails or not talking to them; (2) “neutral” practices (62 sequences) such as talking to calves, moving quickly and pushing the calves and (3) mostly “positive” practices (83 sequences) such as touching the calves, not hitting or pushing them and not twisting their tails. The group using “positive” practices spent significantly less time weighing a calf than the two other groups (p

International audience; The human-animal relationship plays a major role in animal welfare, production, and farmers' work safety. However, few on-farm experiments have been conducted with beef cattle to assess the human-animal relationship. This exploratory study on beef cattle farms aimed to investigate relationships between farmers' practices (herd management), attitudes towards their animals and handling, and animals' reactions to humans. This study was conducted on 20 French beef cattle farms with a wide range of sizes (utilized agricultural area, permanent pasture area and number of cattle). A semi-structured interview to understand practices related to the human-animal relationship, a questionnaire assessing farmers' attitudes towards their animals and animal handling, and a behavioral test of animals' reactions to humans (an avoidance test) were performed. A Generalized Linear Mixed Model was used to analyze relations among data. Farm size characteristics were not related to animal fear responses. Farmers reporting a lack of time for handling their cattle monitored them less frequently (p < 0.05). Their cattle kept a larger avoidance distance from an unfamiliar human during the avoidance test (p < 0.01). Avoidance distance also tended to be larger for the cattle of farmers who reported not making physical contact with cattle when monitoring them and not including behavior as a genetic criterion for selection (p < 0.1). Making physical contact with cattle during monitoring, monitoring frequently, and including behavior in genetic selection were identified as three "relational practices" (i.e., those that farmers purposely adopt to reduce fear responses and improve the human-animal relationship). This exploratory study was able to reveal significant links between farmers' reported practices and animals' behavioral responses.

Chronic stress in farm animals can induce detrimental effects in emotional sensitivity and cognitive function, for example, by altering fearfulness and eliciting pessimistic-like judgment. Based on a few experiments carried out on laboratory animals, we suggest that exposing chronically stressed sheep to an enriched environment could alleviate the detrimental stress-induced effects on fearfulness and judgment. Fifteen lambs (Chronically Stressed lambs, CS) were submitted for 7 weeks to a treatment known to induce chronic stress ( i.e. repeated and unpredictable exposures to various uncontrollable and aversive events every day and/or night). Fifteen other lambs (lambs exposed to Negative and Positive events, NP) were also submitted to the same stressful treatment and, for the last 4 weeks of the stressful treatment, exposed daily to various positive events, i.e. wool brush, positive contact with humans and anticipation of food by a light announcing daily food distribution. Before the treatment, all lambs were individually trained to spatially differentiate between positive and negative reinforced bucket locations with a go/no-go approach response. At the end of the treatment, each lamb was exposed to a judgment test using the same go/no-go design by offering it three ambiguous and unreinforced bucket locations in addition to the two learnt locations. In addition, lambs were exposed to two standard tests of fearfulness (exposure to novelty and suddenness) and human approach test. NP lambs displayed a positive judgement bias: they approached the bucket placed at the ambiguous location that was closest to the positive one faster than CS lambs (3.0s±0.3 vs. 5.9s±1.6; P =0.006). NP lambs approached the human more than their counterparts (15.0±1.4 vs . 7.7±1.5 times in human zone during 10min; P =0.003) and were also more reactive to novelty and suddenness. Thus, repeated exposure lambs to positive events during a stressful period induces an optimistic-like judgment but also increases emotional reactivity. Further studies are thus necessary before promoting such a positive treatment as a method to alleviate negative effects of chronic stress.

International audience; Farming systems can expose animals to chronic mild stress which is known to induce negative affective state. Affective state in animals, as in humans, can be assessed through behavioral cues. This study aimed to describe the effect of a chronic mild stress, known to induce a negative affective state, on sheep health through their response to vaccination. The study used 15 lambs subjected to a model of chronic mild stress for 15 weeks and 15 lambs reared under conventional farming as a control group. After 7 weeks of stressful treatment, the lambs were individually exposed to a judgment bias test to assess a putative stress-induced 'pessimism.' After 15 weeks of stressful treatment, antibody immune response was measured after an injection of a live vaccine challenge (Chlamydia abortus attenuated vaccine strain 1B). Stressed lambs displayed a pessimistic-like perception in the judgment bias test, revealing a negative affective state. Stressed and control animals showed different immunological reactions to vaccine challenge: stressed sheep had lower hemoglobin concentrations and higher platelet, granulocyte and acute-phase protein concentrations. Antibody response induced by the vaccine strain was not different between stressed and control sheep. Our results suggest that negative affective state induced by chronic stress treatment may induce a stronger inflammatory response to vaccine challenge in sheep. Improvement of animal health may be achieved through consideration of stressors that may affect the emotional and immunological state of sheep.

6 pages; International audience; The digestive system of horses is adapted to a high-fiber diet consumed in small amounts over a long time. However, during training, high-starch and low-fiber diets are usually fed which may induce hindgut microbial disturbances and intestinal pain. These diets can be described as alimentary stress. The aim of the present study was to investigate to what extent changes in behavior are associated with alimentary stress and microbial composition changes of the cecal or colonic ecosystem. Six fistulated horses were used. The alimentary stress was a modification of diet from a high-fiber diet (100% hay) to a progressive low-fiber and high-starch diet (from 90% hay and 10% barley to 57% hay and 43% barley in 5 days). Cecal and colonic total anaerobic, cellulolytic, amylolytic and lactate-utilizing bacteria were enumerated three times (twice on high-fiber diet and once on 57% hay and 43% barley diet). The behavior of horses was assessed from continuous video recording over an 18-h time period. In addition two personality traits were measured: neophobia (assessed from the reaction to the presence of a novel object placed near a feeder in a test arena) and sociability (assessed from the reaction to an unfamiliar horse in a stall). Video recordings were analyzed by scan sampling every 10 min using the following behavioral categories: lying, resting, feeding and being vigilant. In addition, we recorded time spent feeding and time spent in vigilance during the neophobia test, and time spent in vigilance and time spent in interactions with the unfamiliar horse during the sociability test. The alimentary stress induced significant increases of colonic total anaerobic bacteria, lactate-utilizing bacteria and amylolytic bacteria concentrations. When horses were fed the 57% hay–43% barley diet, time spent in vigilance tended to be positively correlated with cecal and colonic amylolytic bacteria concentrations during the sociability test and with cecal lactate-utilizing and colonic amylolytic bacteria concentrations during the neophobia test. These correlations suggested that dietary-induced modulation of the microbiota may affect horse behavior and that behavioral cues may be used as non-invasive indicators of alimentary stress. It might prove useful to prevent intestinal pain of horses on farms.

International audience; Between-farm variation in animal reactions to humans can reflect different management styles and behavioral tendencies among farmers. Animals are well known to discriminate among humans, but less clear is the key issue of whether they more or less easily generalize their experience from specific humans to others depending on management style. Here, we chose 2 contrasted management styles by known handlers: “gentle” management, that is, long-lasting exposure to positive human interactions (with limited negative interactions), and “aversive” management including long-lasting exposure to various negative human interactions (with only food delivery considered a positive interaction) and aversive events. Over a period of 19 wk, 15 female lambs were exposed to the gentle management treatment (“gently treated” group) and another 15 lambs (“aversively treated” group) were exposed to the aversive management treatment. To facilitate discrimination by animals, experimenters wore white clothes for aversive events and green clothes for farming handling (positive handling and feeding for the gently treated group and only feeding for the aversively treated group). Sheep perception of the human was assessed after the management period by submitting lambs from each group to 2 standardized tests: 1) the presence of a stationary human (familiar human in white vs. familiar human in green vs. unknown human) and 2) the presence of a moving human (familiar human in white vs. familiar human in green vs. unknown human). As expected, during the stationary human test, aversively treated lambs spent less time in the human zone (P < 0.0001), showed greater latency to approach the human (P = 0.05), and had fewer contacts with the human (P = 0.05) than gently treated lambs. During the moving human test, aversively treated lambs also showed a greater escape distance from humans than gently treated lambs (P < 0.0001). Aversively treated lambs showed the same fear responses towards familiar and unknown humans and tended to generalize their aversive experiences with one handler to all humans. In contrast, gently treated lambs seemed to discriminate familiar humans from unfamiliar humans. Different management styles could modulate farm generalization to humans in farm animals.

Concernant l'affiliation Inra "Physiologie de la reproduction et des comportements" : le codique 6175 indiqué sur la publication est erroné. Le bon codique est 0085.; Chronic stress can be described as a long-term negative affective state induced by an accumulation of negative emotional experiences that alters an individual's interactions with the environment. In humans, chronic stress induces both persistent judgment biases and learning deficits. We investigated whether similar cognitive biases could occur in sheep. Twenty-four lambs were subjected to a chronic stress treatment for 9 weeks (exposure to various unpredictable, uncontrollable and aversive events regularly encountered in ordinary agricultural practices) and 24 other lambs were used as a control group. Before treatment all the lambs had been trained to approach or avoid a food bucket depending on its location. After treatment, the lambs were individually exposed to two tests: (i) a food bucket approach/avoidance test, by testing the response of lambs to ambiguous locations of the bucket, i.e. a judgment bias test, (ii) a learning test consisting of training on six consecutive days to distinguish between two visual stimuli differing in their color and shape (acquisition phase) and re-exposure to the test conditions 2 days after the end of the acquisition phase (recall phase). In the judgment bias test, treated lambs took longer to approach the ambiguous locations of the bucket. During the learning test, treated lambs had lower numbers of correct choices than control lambs in the acquisition and recall phase. Hence sheep experiencing repeated aversive events demonstrated pessimistic-like judgment biases and learning deficits. These may be useful measures to assess long-term emotional states in animals.

Numerous studies have investigated the emotional effects of various acute, potentially alarming events in animals, but little is known about how an accumulation of emotional experiences affects fearfulness. Fearfulness is a temperament trait that characterizes the propensity of an individual to be frightened by a variety of alarming events. The aim of this study was to investigate a putative alteration of fearfulness in sheep repeatedly exposed to various aversive events. Forty-eight 5-month-old female lambs were used. Over a period of 6 weeks, 24 of them (treated group) were exposed daily to various unpredictable and uncontrollable aversive events related to predatory cues, social context and negative handling that can occur under farming conditions. The other 24 lambs (control group) were housed in standard farming conditions (predictable food distribution and group handling). Fearfulness (behavioural and physiological responses) was assessed before and after the treatment period by subjecting the lambs to three standardized tests: individual exposure to suddenness and then to novelty in a test arena, and group exposure to a motionless human in the home pen. As biomarkers of stress, leukocyte counts, heart rate and cortisol concentrations were measured in the lambs in their home pens. Before the treatment, the emotional responses of the groups did not differ. After the treatment, treated lambs approached the human less often, had less contact with the novel object and vocalized more than controls in individual tests, suggesting that long-term exposure to unpredictable and uncontrollable aversive events increases subsequent fearfulness in sheep. In addition, treated lambs had lower leukocyte counts, heart rate and cortisol levels, pointing to a chronic stress state. These findings suggest that increased fearfulness may be used as a sign of chronic stress in farm animals.

International audience; Recent studies emphasize the role of interactions between emotions and judgment of environment to better assess affective state in animals. Diazepam offers a way to pharmacologically manipulate the affective state. This drug is generally used to reduce negative affective states, mainly by reducing fearfulness. Here we investigated whether a reduction of fearfulness through a pharmacological approach could reduce pessimistic-like judgment in lambs. We tested the effects of diazepam (0.10 mg/kg), a benzodiazepine known for its anxiolytic properties in many species, in 5-months old female lambs submitted to two experiments: the first one to assess their fear-related reactions (cortisol, cardiac and behavioural measures) to isolation and suddenness tests, and the second one to assess their putative judgment bias. In experiment 1, the lambs treated with diazepam were less frightened by isolation and suddenness than the control lambs injected with vehicle, which tended to confirm the anxiolytic effect of diazepam on sheep. In experiment 2, the lambs were first trained to perform a spatial location task to test for judgment bias in sheep. This task required a go/no-go response according to the location of a bucket in a pen, with one location being reinforced positively (with a feed reward) and the other negatively (with a fan-forced blower). Once trained, lambs (n = 16) were exposed twice (10 min and 3 h after injections) to five consecutive bucket locations: the two learnt locations plus three unrewarded, ambiguous locations set between the learnt locations. Control lambs increased their latency to approach one of the ambiguous bucket locations (P < 0.05), while treated lambs maintained the same latency to approach this location. This difference may reflect a bias in judgment in relation to fearfulness: treated lambs seemed to display a more positive judgment of an ambiguous event than control lambs. Reduction of fearfulness may thus induce a more positive affective state but this requires further investigation, with additional studies comparing the efficacy of the cognitive bias approach to other measures of affective state.