Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm.publishedVersio

Hétérogénéité interindividuelle de performances démographiques et personnalité chez le Chevreuil européen (Capreolus capreolus).

Identifying the factors that influence the inter-individual variations of life history traits is important to understand the dynamics of natural populations, as well as to direct the conservation management of wild species. Recently, it has been shown that personality may also modify the way individuals cope with life-history trade-offs. Therefore, in this thesis, I focused on inter-individual variability in behavior in a large wild herbivore, the roe deer (Capreolus capreolus), and I explored its potential impact on components of individual fitness. I highlighted strong multi-dimensionality, in the behavioral expression of individuals with the existence of behavioral syndromes, but also with intra-individual correlations among levels. I also identified fitness consequences of the behavioral syndrome with, for example, an impact on the survival and growth of offspring. Thus, personality seems to affect the fate of individuals, as well as that of its offspring, and, in fine, the population’s dynamics.Il est important de pouvoir identifier les facteurs influençant la variabilité interindividuelle dans les traits d’historie de vie pour comprendre la dynamique des populations. En parallèle, il a été montré que la personnalité pouvait modifier la manière dont les individus gèrent des compromis d’histoire de vie. C’est dans ce contexte que se situe cette étude, à savoir que l’objectif était de mesurer la variabilité interindividuelle comportementale chez le chevreuil et d’explorer ses liens potentiels avec les composants de la valeur sélective des individus. J’ai montré que cette variabilité interindividuelle comportementale est multidimensionnelle que ce soit dans l’expression du comportement des individus avec la mise en évidence de syndromes comportementaux ou dans les corrélations entre niveaux (comportemental, physiologique, hormonal) d’expression à l’échelle intra-individuelle. De plus, ces syndromes comportementaux affectent les traits d’historie de vie de l’individu, mais aussi la survie et croissance des faons. Ainsi, la personnalité semble affecter l’avenir de l’individu tout au long de sa vie de même que sa progéniture et, in fine, la dynamique des populations

Predator-induced transgenerational plasticity in animals : a meta-analysis

There is growing evidence that the environment experienced by one generation can influence phenotypes in the next generation via transgenerational plasticity (TGP). One of the best-studied examples of TGP in animals is predator-induced transgenerational plasticity, whereby exposing parents to predation risk triggers changes in offspring phenotypes. Yet, there is a lack of general consensus synthesizing the predator–prey literature with existing theory pertaining to ecology and evolution of TGP. Here, we apply a meta-analysis to the sizable literature on predator-induced TGP (441 effect sizes from 29 species and 49 studies) to explore five hypotheses about the magnitude, form and direction of predator-induced TGP. Hypothesis #1: the strength of predator-induced TGP should vary with the number of predator cues. Hypothesis #2: the strength of predator-induced TGP should vary with reproductive mode. Hypothesis #3: the strength and direction of predator-induced TGP should vary among offspring phenotypic traits because some traits are more plastic than others. Hypothesis #4: the strength of predator-induced TGP should wane over ontogeny. Hypothesis #5: predator-induced TGP should generate adaptive phenotypes that should be more evident when offspring are themselves exposed to risk. We found strong evidence for predator-induced TGP overall, but no evidence that parental predator exposure causes offspring traits to change in a particular direction. Additionally, we found little evidence in support of any of the specific hypotheses. We infer that the failure to find consistent evidence reflects the heterogeneous nature of the phenomena, and the highly diverse experimental designs used to study it. Together, these findings set an agenda for future work in this area

Neophobia is linked to behavioural and haematological indicators of stress in captive roe deer

Neophobia is an important personality trait that allows animals to minimize exposure to threat. We investigated the existence of consistent individual differences in the level of neophobia in captive roe deer, Capreolus capreolus, using an experimental set-up. Our main objective was to explore the link between an individual's level of neophobia with behavioural and physiological responses measured during a stressful situation, i.e. capture and restraint, to facilitate characterization of neophobia in the wild. We found that the probability of initiating a feeding bout and the feeding efficiency over bouts both decreased in the presence of a novel object. However, there was pronounced variation in the degree to which individuals were affected by the experimental treatment. First, feeding efficiency decreased the most among individuals that reacted less markedly to an acutely stressful situation (capture). Second, latency between the first visit and the first feeding bout increased the most among individuals that had a higher concentration of fructosamine in their blood, an indicator of chronic stress. Our results indicate that individuals that are more neophobic (high latency to first feeding bout and low feeding efficiency in the presence of a novel object) are also less proactive (low behavioural response to capture, high levels of fructosamine), suggesting the existence of a behavioural syndrome. We conclude that behavioural and physiological parameters measured during capture provide reliable indicators of neophobia for roe deer, providing an exciting new avenue for the study of animal personality in the wild

Co-variation between glucocorticoids, behaviour and immunity supports the pace-of-life syndrome hypothesis: an experimental approach

The biomedical literature has consistently highlighted that long-term elevation of glucocorticoids might impair immune functions. In wild animals, patterns are less clear. Here, we re-explored the stress-immunity relationship considering the potential effects of behavioural profiles. Thirteen captive roe deer ( Capreolus capreolus ) were monitored over an eight-week period encompassing two capture events. We assessed how changes in baseline faecal cortisol metabolite (FCM) concentrations following a standardised capture protocol and vaccination affected changes in thirteen immune parameters of the innate and adaptive immunity, and whether behavioural profiles were linked to changes in baseline FCM levels and immune parameters. We found that individuals showing an increase in baseline FCM levels also exhibited an increase in immunity and were characterised by more reactive behavioural profiles (low activity levels, docility to manipulation and neophilia). Our results suggest that immunity of large mammals may be influenced by glucocorticoids, but also behavioural profiles, as it is predicted by the pace-of-life syndrome hypothesis. Our results highlight the need to consider co-variations between behaviour, immunity and glucocorticoids in order to improve our understanding of the among-individual variability in the stress-immunity relationships observed in wildlife, as they may be underpinned by different life-history strategies

Clostridium difficile infection and immune checkpoint inhibitor–induced colitis in melanoma: 18 cases and a review of the literature

International audienceImmunotherapy has become the standard of care for several types of cancer, such as melanoma. However, it can induce toxicity, including immune checkpoint inhibitor-induced colitis (CIC). CIC shares several clinical, histological, biological, and therapeutic features with inflammatory bowel disease (IBD). Clostridium difficile infection (CDI) can complicate the evolution of IBD. We aimed to characterize the association between CDI and CIC in patients treated with anti-CTLA-4 and anti-PD-1 for melanoma. Patients from nine centers treated with anti-CTLA-4 and anti-PD-1 for melanoma and presenting with CDI from 2010 to 2021 were included in this retrospective cohort. The primary endpoint was the occurrence of CIC. The secondary endpoints were findings allowing us to characterize CDI. Eighteen patients were included. Eleven were treated with anti-PD-1, four with anti-CTLA-4, and three with anti-PD-1 in combination with anti-CTLA-4. Among the 18 patients, six had isolated CDI and 12 had CIC and CDI. Among these 12 patients, eight had CIC complicated by CDI, three had concurrent CIC and CDI, and one had CDI followed by CIC. CDI was fulminant in three patients. Endoscopic and histological features did not specifically differentiate CDI from CIC. Nine of 11 patients required immunosuppressive therapy when CDI was associated with CIC. In nine cases, immunotherapy was discontinued due to digestive toxicity. CDI can be isolated or can complicate or reveal CIC. CDI in patients treated with immunotherapy shares many characteristics with CDI complicating IBD. Stool tests for Clostridium difficile should be carried out for all patients with diarrhea who are being treated with immunotherapy

Co-variation between glucocorticoids, behaviour and immunity supports the pace-of-life syndrome hypothesis: an experimental approach

International audienceThe biomedical literature has consistently highlighted that long-term elevation of glucocorticoids might impair immune functions. In wild animals, patterns are less clear. Here, we re-explored the stress-immunity relationship considering the potential effects of behavioural profiles. Thirteen captive roe deer ( Capreolus capreolus ) were monitored over an eight-week period encompassing two capture events. We assessed how changes in baseline faecal cortisol metabolite (FCM) concentrations following a standardised capture protocol and vaccination affected changes in thirteen immune parameters of the innate and adaptive immunity, and whether behavioural profiles were linked to changes in baseline FCM levels and immune parameters. We found that individuals showing an increase in baseline FCM levels also exhibited an increase in immunity and were characterised by more reactive behavioural profiles (low activity levels, docility to manipulation and neophilia). Our results suggest that immunity of large mammals may be influenced by glucocorticoids, but also behavioural profiles, as it is predicted by the pace-of-life syndrome hypothesis. Our results highlight the need to consider co-variations between behaviour, immunity and glucocorticoids in order to improve our understanding of the among-individual variability in the stress-immunity relationships observed in wildlife, as they may be underpinned by different life-history strategies

Co-variation between glucocorticoids, behaviour and immunity supports the pace-of-life syndrome hypothesis: an experimental approach

The biomedical literature has consistently highlighted that long-term elevation of glucocorticoids might impair immune functions. In wild animals, patterns are less clear. Here, we re-explored the stress-immunity relationship considering the potential effects of behavioural profiles. Thirteen captive roe deer ( Capreolus capreolus ) were monitored over an eight-week period encompassing two capture events. We assessed how changes in baseline faecal cortisol metabolite (FCM) concentrations following a standardised capture protocol and vaccination affected changes in thirteen immune parameters of the innate and adaptive immunity, and whether behavioural profiles were linked to changes in baseline FCM levels and immune parameters. We found that individuals showing an increase in baseline FCM levels also exhibited an increase in immunity and were characterised by more reactive behavioural profiles (low activity levels, docility to manipulation and neophilia). Our results suggest that immunity of large mammals may be influenced by glucocorticoids, but also behavioural profiles, as it is predicted by the pace-of-life syndrome hypothesis. Our results highlight the need to consider co-variations between behaviour, immunity and glucocorticoids in order to improve our understanding of the among-individual variability in the stress-immunity relationships observed in wildlife, as they may be underpinned by different life-history strategies

Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm

Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm