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[hal-04840794] Transitive reasoning in the adult domestic hen in a six-term series task
Transitive inference (TI) is a disjunctive syllogism that allows an individual to indirectly infer a relationship between two components, by knowing their respective relationship to a third component (if A > B and B > C, then A > C). The common procedure is the 5-term series task, in which individuals are tested on indirect, unlearned relations. Few bird species have been tested for TI to date, which limits our knowledge of the phylogenetic spread of such reasoning ability. Here we tested TI in adult laying hens using a more solid methodology, the 6-term series task, which has not been tested in poultry so far. Six hens were trained to learn direct relationships in a sequence of six arbitrary items (A > B > C > D > E > F) in a hybrid training procedure. Then, 12 testing sessions were run, comprising 3 non-rewarded inference trials each: BD, BE, and CE. All subjects showed TI within 12 inference trials and were capable of TI whatever the relative distance between the items in the series. We found that TI performance was not impacted by the reinforcement ratios of the items for most individuals, making it harder to support a purely associative-based resolution of the task. We suggest that TI is based on the same cognitive processes in poultry ( Galloanserae ) than in modern flying birds ( Neoaves ), and that the cognitive strategy to solve the task might be driven mainly by individual parameters within species. These results contribute to a better understanding of transitive inference processes in birds.
ano.nymous@ccsd.cnrs.fr.invalid (R. Degrande) 16 Dec 2024
https://hal.inrae.fr/hal-04840794v1
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[hal-04699728] L’élevage de poulets biologiques : les verrous à lever et les opportunités offertes par cette production
La France est actuellement au premier rang des productions européennes de poulets biologiques. Cette production ne représente toutefois encore que quelques pourcents de la production nationale. L’élevage avicole biologique est souvent considéré comme respectueux du bien-être animal et de l’environnement. Cependant, au-delà de ces images positives que l’élevage avicole biologique et les produits biologiques véhiculent, certaines contraintes déjà identifiées limitent leur développement. Le contact avec la faune sauvage présentant un risque sanitaire, la gestion du parcours, les tensions sur l’environnement dues à une excrétion des déjections sur le parcours difficilement maîtrisable et la sensibilité au contexte économique et aux comportements de consommation sont autant d’obstacles. L’élevage biologique offre néanmoins des opportunités 1) pour l’animal : le parcours facilite l’expression de nombreux comportements et permet la consommation d’insectes et de plantes possédant diverses propriétés (nutritionnelle, médicinales…) ; 2) pour l’éleveur : une amélioration des conditions de travail ainsi qu’une plus grande satisfaction sont mises en avant ; 3) pour l’environnement : le parcours constitue une source de biodiversité. Après une présentation des conditions d’élevage des poulets biologiques en France et en Europe, nous proposons d’identifier les barrières à l’extension de l’élevage biologique et les leviers/opportunités pour les dépasser.
ano.nymous@ccsd.cnrs.fr.invalid (Karine Germain) 17 Sep 2024
https://hal.inrae.fr/hal-04699728v1
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[hal-04637092] Early and late cognitive and behavioral aspects associated with range use in free-range laying hens (Gallus gallus domesticus)
Individual differences in free-range chicken systems are important factors in fluencing how birds use the range (or not), even if individuals are reared in the same environmental conditions. Here, we investigated how various aspects of the birds ' behavioral and cognitive tendencies, including their optimism/pessimism, cognitive flexibility, sociability, and exploration levels, are associated with range use and how they may change over time (before and after range access). To achieve this, 100 White Leghorn laying hen chicks underwent three distinct behavioral/cognitive tests - the cognitive bias test, the detour test, and the multivariate test -prior to gaining access to the range, between 9 and 39 days of age. After range access was allowed (from day 71), birds ' range use was evaluated over 7 nonconsecutive days (from 74 -91 days of age). Subsequently, a subset of birds, classi fied as high rangers (n = 15) and low rangers (n = 15) based on their range use, underwent retesting on the same three previous tests between 94 and 108 days of age. Our results unveiled a negative correlation trend between birds ' evaluation of the ambiguous cue and their subsequent range use (rho =0.19, p = 0.07). Furthermore, low rangers were faster to learn the detour task ( x2 = 7.34, df = 1, p = 0.006), coupled with increased sociability during the multivariate test (rho = -0.23, p = 0.02), contrasting with their highranging counterparts, who displayed more exploratory behaviors (F[1,27] = 3.64, p = 0.06). These behavioral patterns fluctuated over time (before and after range access); however, conclusively attributing these changes to birds ' aging and development or the access to the range remains challenging. Overall, our results corroborate that behavioral and cognitive individual differences may be linked to range use and offer novel perspectives on the early behavioral and cognitive traits that may be linked to range use. These findings may serve as a foundation for adapting environments to meet individual needs and improve animal welfare in the future.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 05 Jul 2024
https://hal.inrae.fr/hal-04637092v1
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[hal-04548377] Discrimination of familiar and unfamiliar human voices is independent of prolonged human-animal interaction in domestic chicks
Different animal species, both domestic and wild, can discriminate between various human cues, such as voices, and adjust their behavior based on whether they are familiar or unfamiliar with these cues. To investigate whether this ability extends to a domesticated species not specifically bred for human interaction and whether it can manifest at an early age, even under commercial-like conditions with limited human interaction, we conducted human vocal discrimination tests on domestic chicks at two ages (25 and 67 days old). Our findings showed that chicks could discriminate between familiar and unfamiliar voices at both ages, exhibiting increased vigilance when a known sentence was spoken by an unfamiliar voice compared to a familiar voice. We also found that chicks were more vigilant after a familiar voice delivered an unknown sentence, compared to an unfamiliar voice delivered a known sentence. This suggests a violation of expectation when animals are confronted with mixed familiar/unfamiliar heterospecific signals. Our findings support that neither specific selection for interaction with humans, nor an extended history of exposure to humans, is a prerequisite for animals to discriminate heterospecific cues, such as human voices.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 16 Apr 2024
https://hal.inrae.fr/hal-04548377v1
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[hal-04524493] Are domesticated animals dumber than their wild relatives? A comprehensive review on the domestication effects on animal cognitive performance
Animal domestication leads to diverse behavioral, physiological, and neurocognitive changes in domesticated species compared to their wild relatives. However, the widely held belief that domesticated species are inherently less "intelligent" (i.e., have lower cognitive performance) than their wild counterparts requires further investigation. To investigate potential cognitive disparities, we undertook a thorough review of 88 studies comparing the cognitive performance of domesticated and wild animals. Approximately 30% of these studies showed superior cognitive abilities in wild animals, while another 30% highlighted superior cognitive abilities in domesticated animals. The remaining 40% of studies found similar cognitive performance between the two groups. Therefore, the question regarding the presumed intelligence of wild animals and the diminished cognitive ability of domesticated animals remains unresolved. We discuss important factors/limitations for interpreting past and future research, including environmental influences, diverse objectives of domestication (such as breed development), developmental windows, and methodological issues impacting cognitive comparisons. Rather than perceiving these limitations as constraints, future researchers should embrace them as opportunities to expand our understanding of the complex relationship between domestication and animal cognition.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 28 Mar 2024
https://hal.inrae.fr/hal-04524493v1
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[hal-04219741] Comment les volailles perçoivent et interprètent leur environnement : recherche scientifique et exemples d’applications
La science s’intéresse de longue date aux pratiques d’élevage et à la notion de sensibilité animale. En accord avec ces questionnements, il existe une demande sociétale croissante pour l’amélioration des conditions de vie des animaux de rente. Cette amélioration nécessite des connaissances de leurs capacités cognitives, qui permettent à l’animal de traiter, mémoriser, interpréter ce qui se passe dans son environnement. Ces connaissances permettent d’expliquer voire limiter certains comportements observés en élevage. [ Cet article est issu d’une synthèse présentée aux 14èmes Journées de la Recherche Avicole des 9-10 mars 2022 à Tours. (Calandreau et al., 2022) ]
ano.nymous@ccsd.cnrs.fr.invalid (Rachel Degrande) 27 Sep 2023
https://hal.inrae.fr/hal-04219741v1
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[hal-04109688] Cognitive enrichment to increase fish welfare in aquaculture: A review
While most animals have received increasing attention for their welfare, consideration for fish welfare has started more recently, particularly since the recognition that fish have emotions and complex cognitive abilities. Housing conditions in fish farms do not always meet fish ethological requirements as these conditions lack sufficient sensory and cognitive stimulations. An approach to address this issue involves enriching the rearing environment by including social, food, physical, or cognitive stimuli. Cognitive enrichment (CE) is a recent but promising concept to improve fish welfare by manipulating the predictability and controllability of their environment. It relies not only on the ability of fish to predict positive and negative events but also on their ability to perform and succeed in operant conditioning. In our present review, we identified four categories of CE: (i) feeding predictability, (ii) predictability of a negative event, (iii) operant conditioning through self-feeders, and (iv) learning experiences. Existing CEs were reviewed for their effects on behaviour, brain, zootechnical performances, and welfare in terms of physiological stress or physical integrity in the aquarium and farmed teleost fish. The review highlights unbalanced categories and the lack of adequate multidisciplinary analyses to assess the effects of these categories on fish welfare. Providing free access to self-feeders seems to be a good strategy, given its positive effects on zootechnical and physiological parameters. Other categories showed contradictory and species-dependent results; hence, further studies are required to confirm the benefits of CE on fish welfare. Finally, further investigations should also validate current CE systems and assess other strategies that may trigger positive emotions in fish.
ano.nymous@ccsd.cnrs.fr.invalid (Aude Kleiber) 14 Mar 2024
https://hal.inrae.fr/hal-04109688v1
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[hal-04052261] Behavioural indicators of range use in four broiler strains
Free-range systems provide an outdoor range for broilers to give them the possibility to express a higher frequency and a wider range of behaviours, such as exploration, compared with those raised indoors. Greater variability in outdoor range use between individuals of the same flock is often reported. Individual variation in range use may result from differences in early-life behaviour or genetic background. Understanding how earlylife behaviour influences range use may provide opportunities to enhance and predict range use. Previous studies have shown that range use could be influenced by the animal’s personality traits such as social motivation, boldness and foraging motivation. Therefore, this study investigated personality traits in several broiler strains, namely Hubbard JA757, Hubbard S757N, White Bresse and a dual-purpose strain; we examined the latter as it represents a potential solution to the ban of 1-day-old chick culling. The present study also investigated early-life behaviours, before range access, of range use to identify and assess the stability of these early-life indicators among the four broiler strains. For that purpose, we recorded the behaviour and range use of 100 male chickens per strain, both in the barn and during individual tests, before and after range access. We examined which behaviours were time consistent, whether early-life behaviours were influenced by genetic variation and whether early-life behavioural indicators predicted range use regardless of genetic variation. There was a significant (p < 0.001) difference between strains in several early-life behaviours, including the time spent resting or standing. Range use was time consistent regardless of the strain as our range use indicator followed a high-quality linear regression model (R2 > 0.7) for 82–99% of the individuals depending on their strain. Besides, time consistency of social motivation and boldness seemed to depend on the strain. Even though foraging showed low (rho = 0.2–0.4) positive correlations with range use in three of the four studied strains, there were no significant and strong correlations in the four studied strains between early-life behavioural indicators and range use. In conclusion, our results show that the link between chick behaviour (before range access) and range use can be modulated by the bird’s strain. It is crucial to consider all these different factors to better understand how range use varies within and between flocks.
ano.nymous@ccsd.cnrs.fr.invalid (Claire Bonnefous) 30 Mar 2023
https://hal.inrae.fr/hal-04052261v1
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[hal-04185480] Short photoperiod modulates behavior, cognition and hippocampal neurogenesis in male Japanese quail
The mechanisms underlying the photoperiodic control of reproduction in mammals and birds have been recently clarified. In contrast, the potential impact of photoperiod on more complex, integrative processes, such as cognitive behaviors, remains poorly characterized. Here, we investigated the impact of contrasted long and short photoperiods (LP, 16 h light/day and SP, 8 h light/day, respectively) on learning, spatial orientation abilities, and emotional reactivity in male Japanese quail. In addition, we quantified cell proliferation and young cell maturation/migration within the hippocampus, a brain region involved in spatial orientation. Our study reveals that, in male quail, SP increases emotional responses and spatial orientation abilities, compared to LP. Behaviorally, SP birds were found to be more fearful than LP birds, exhibiting more freezing in the open field and taking longer to exit the dark compartment in the emergence test. Furthermore, SP birds were significantly less aggressive than LP birds in a mirror test. Cognitively, SP birds were slower to habituate and learn a spatial orientation task compared to LP birds. However, during a recall test, SP birds performed better than LP birds. From a neuroanatomical standpoint, SP birds had a significantly lower density of young neurons, and also tended to have a lower density of mature neurons within the hippocampus, compared to LP birds. In conclusion, our data reveal that, beyond breeding control, photoperiod also exerts a profound influence on behavior, cognition, and brain plasticity, which comprise the seasonal program of this species.
ano.nymous@ccsd.cnrs.fr.invalid (Marion Georgelin) 22 Aug 2023
https://hal.inrae.fr/hal-04185480v1
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[hal-04185498] Effects of domestication on responses of chickens and red junglefowl to conspecific calls: A pilot study
Beyond physical and zootechnical characteristics, the process of animal domestication has also altered how domesticated individuals, compared to their wild counterparts, perceive, process, and interact with their environment. Little is known, however, on whether and how domestication altered the perception of conspecific calls on both domesticated and wild breeds. In the present work, we compared the vigilance behavior of domestic and captive-born wild fowl following the playback of chicken alarm calls and contentment calls (control). The playback tests were performed on four different breeds/lines. We first compared the behavioral reaction of domesticated White Leghorn (WL, a breed selected for egg production) and Red Junglefowl (RJF) hens (ancestor of domestic chickens). We also compared the behavior of Red Junglefowl hens selected for high or low fear of humans (RJF HF and RJF LF, respectively), a proxy to investigate early effects of domestication. Contrary to our expectations, no breed/line reacted accordingly to the calls, as the increase in vigilance behavior after the playback calls was similar for both alarm and contentment calls. Although no call discrimination differences were found, breeds did differ on how they reacted/habituated to the calls. Overall, WL were more vigilant than RJF, and birds from the RJF LF line decreased their vigilance over testing days, while this was not the case for the RJF HF line. These results suggest that birds under commercial-like conditions are unable to discriminate between alarm and contentment calls. Interestingly, domestication and selection for low fear of humans may have altered how birds react to vocal stimuli. It is important to consider that farmed animals may interpret and be affected by the vocalizations of their conspecifics in unexpected ways, which warrants further investigation.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 22 Aug 2023
https://hal.inrae.fr/hal-04185498v1
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[hal-03626271] Pet-directed speech improves horses’ attention toward humans
In a recent experiment, we showed that horses are sensitive to pet-directed speech (PDS), a kind of speech used to talk to companion animals that is characterized by high pitch and wide pitch variations. When talked to in PDS rather than adult-directed speech (ADS), horses reacted more favorably during grooming and in a pointing task. However, the mechanism behind their response remains unclear: does PDS draw horses’ attention and arouse them, or does it make their emotional state more positive? In this study, we used an innovative paradigm in which female horses watched videos of humans speaking in PDS or ADS to better understand this phenomenon. Horses reacted differently to the videos of PDS and ADS: they were significantly more attentive and their heart rates increased significantly more during PDS than during ADS. We found no difference in the expressions of negative or positive emotional states during PDS and ADS videos. Thus, we confirm that horses’ perception of humans can be studied by means of video projections, and we conclude that PDS attracts attention and has an arousing effect in horses, with consequences on the use of PDS in daily interactions with them.
ano.nymous@ccsd.cnrs.fr.invalid (Plotine Jardat) 31 Mar 2022
https://hal.inrae.fr/hal-03626271v1
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[hal-03746208] Positive effects of bubbles as a feeding predictor on behaviour of farmed rainbow trout
Occupational enrichment emerges as a promising strategy for improving the welfare of farmed animals. This form of enrichment aims to stimulate cognitive abilities of animals by providing them with more opportunities to interact with and control their environment. Predictability of salient daily events, and in particular predictability of feeding, is currently one of the most studied occupational enrichment strategies and can take several forms. In fish, while temporal predictability of feeding has been widely investigated, signalled predictability (based on a signal, such as light or sound) has received little attention. Depending on the type of predictability used and the ecology of the species, the effects on fish welfare often differ. The present study aimed to determine which feeding predictability would be most appropriate for rainbow trout, the main continental farmed fish in Europe, and what the consequences might be for their welfare. We tested four feeding predictability conditions: temporal (based on time of day), signalled (based on bubble diffusion), temporal + signalled (based on time and bubble diffusion), and unpredictable (random feeding times). Behavioural and zootechnical outcomes recorded were swimming activity, aggressive behaviours, burst of accelerations, and jumps, emotional reactivity, and growth. Our results showed that rainbow trout can predict daily feedings relying on time and/or bubbles as predictors as early as two weeks of conditioning, as evidenced by their increased swimming activity before feeding or during feed omission tests, which allowed to reinforce their conditioned response. Temporal predictability alone resulted in an increase in pre-feeding aggressive behaviours, burst of accelerations, and jumps, suggesting that the use of time as the sole predictor of feedings in husbandry practices may be detrimental to fish welfare. Signalled predictability with bubbles alone resulted in fewer pre-feeding agonistic behaviours, burst of accelerations, and jumps than in the temporal predictability condition. The combination of temporal and signalled predictability elicited the highest conditioned response and the level of pre-feeding aggression behaviours, burst of accelerations and jumps tended to be lower than for temporal predictability alone. Interestingly, fish swimming activity during bubble diffusion also revealed that bubbles were highly attractive regardless of the condition. Rainbow trout growth and emotional reactivity were not affected by the predictability condition. We conclude, therefore, that the use of bubbles as a feeding predictor could represent an interesting approach to improve rainbow trout welfare in farms, by acting as both an occupational and physical enrichment.
ano.nymous@ccsd.cnrs.fr.invalid (Aude Kleiber) 31 Aug 2022
https://hal.inrae.fr/hal-03746208v1
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[hal-04185493] White Leghorn and Red Junglefowl female chicks use distal and local cues similarly, but differ in persistency behaviors, during a spatial orientation task
Although there is evidence to suggest that animal domestication acts as a modulator of spatial orientation, little is known on how domesticated animals, compared to their wild counterparts, orientate themselves when confronted to different environmental cues. Here, using domesticated White Leghorn chicks, and their ancestor, the Red Junglefowl (Gallus gallus), our main objective was to investigate how bird domestication influences the use of distal and local cues, during an orientation task. We also investigated the memory retention of these cues over time, and how persistent/flexible individuals from both breeds were at pecking at unreachable mealworms. Our results showed that the breeds did not differ in their use of distal or local cues, with both showing a marked preference for the use of local cues over distal ones. Over time, individual performance declined, but this was not influenced by the type of cue present during the tests, nor by the breed. Domesticated chicks showed greater signs of persistency compared to their wild conspecifics. In conclusion, domestication did not seem to alter how birds orientate spatially, but may have caused more subtle changes, such as an increase in behavioral persistency, a feature that may be adaptative in human-controlled and homogenous environments.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 22 Aug 2023
https://hal.inrae.fr/hal-04185493v1
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[hal-03627159] Foraging Behavior Shows Individual-Consistency Over Time, and Predicts Range Use in Slow-Growing Free-Range Male Broiler Chickens
Recent research on free-range chickens shows that individual behavioral differences may link to range use. However, most of these studies explored individual behavioral differences only at one time point or during a short time window, assessed differences when animals were out of their social group and home environment (barn and range), and in specific tests or situations. Therefore, it is yet unclear how different behaviors relate to range use and how consistent these behaviors are at the individual level. To fill this gap, we here aimed to describe the behavioral budget of slow-growing male broiler chickens (S757N) when in their social group and home environment during the whole rearing period (from the second week of life to the twelfth week, before slaughter), and to relate observed behavioral differences to range use. For this, we followed a sample of individuals in two flocks ( n = 60 focal chickens out of 200 chickens per flock), over two seasons, during three periods: before range access (from 14 to 25 days old), during early range access (first weeks of range access, from 37 to 53 days old), and during late range access (last weeks of range access, from 63 to 87 days old). By the end of each period, individual tests of exploration and social motivation were also performed, measuring exploration/activity and sociability propensities. Our results show that foraging (i.e., pecking and scratching at the ground) was the only behavior that correlated to range use for all three rearing periods, independent of the season. Foraging was also the only behavior that showed within-individual consistency from an early age and across the three rearing periods. Foraging may, therefore, serve as a useful behavioral predictor of range use in free-range broiler chickens. Our study increases the knowledge of how behaviors develop and relate to each other in a domesticated and intensely selected species, and improves our understanding of the biology of free-range broiler chickens. These findings can, ultimately, serve as a foundation to increase range use and improve chicken welfare.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 03 May 2024
https://hal.inrae.fr/hal-03627159v1
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[hal-03207748] Loss of light colour preference after chronic embryonic stress in rainbow trout fry: a novel and potential indicator of fish welfare?
For many fish species, environmental colour may act either as a source of stress or as a stress-buffer, alleviating behavioural and physiological responses after a stressful situation. While much is known on the effects of environmental colour on fish stress parameters, knowledge on the effects of stress on fish colour preferences is still lacking. In order to test the effects of stress on colour preference in fish, in this work, we exposed rainbow trout embryos (Oncorhynchus mykiss) to stressful conditions (air exposure, pheromone alarm cue or control, with minimal stress) from 19 to 44 days post fertilization (dpf). They were then raised up to 56 dpf in bright, dark, green or blue environments. After that, fry were individually tested for colour preference in a three-chambered arena where they could choose between green and blue areas. The time spent in the blue and in the green chamber was compared between experimental groups. Rainbow trout fry exposed to minimal stress (control) or to biotic stress (pheromone alarm) showed increased time in the blue environment, with little effect of ambient colour where they were raised. However, fish that experienced air exposure stress showed a lack of colour preference irrespective of the colour they were raised in afterwards. These results imply that early life stress affects colour preference in rainbow trout, suggesting that abiotic stressors, such as air exposure, may affect colour perception or behavioural plasticity in young fish. If the results presented herein are corroborated by future studies in fish at different life stages, beyond the embryonic phase, colour preference tests may be used as an additional and potential welfare indicator to estimate, in a retrospective manner, which stressors were faced by the individuals during early stages. By knowing whether or not their fish were exposed to certain stressful conditions may allow farmers to better adapt fish rearing conditions and to implement strategies that alleviate any long-term impacts that may exist, and, therefore, improve fish welfare.
ano.nymous@ccsd.cnrs.fr.invalid (Violaine Colson) 08 Jul 2022
https://hal.inrae.fr/hal-03207748v1
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[hal-03369464] Training level reveals a dynamic dialogue between stress and memory systems in birds
Chronic stress profoundly affects forms of declarative memory, such as spatial memory, while it may spare nondeclarative memory, such as cue-based memory. It is known, however, that the effects of chronic stress on memory systems may vary according to the level of training of an individual was submitted. Here, we investigated, in birds, how chronic stress impact spatial and cue-based memories according to training level. For that, control and chronically stressed Japanese quail were trained in a task that could be solved using spatial and cuebased memory and tested for their memory performance after 5 and 15 training days (initial training and overtraining, respectively) and following an emotional challenge (exposure to an open field). Our results showed that, compared to control quail, chronic stress impacted negatively spatial memory performances in stressed birds after initial training, but these differences were lowered after overtraining. Control birds seemed to shift from spatial to cue-based memory to solve the task across overtraining. However, an emotional challenge before testing reinstated the negative impact of chronic stress on spatial memory performances between the groups, revealing that chronic stress/overtraining did not eliminate the spatial memory and differences caused by stressors can reemerge depending on the individual?s immediate psychological state. Contrary to spatial memory, cue-based memory was not affected in chronically stressed birds compared to control birds in any test occasion, confirming its resistance against the negative effects of chronic stress. Altogether these findings reveal a dynamic dialogue between stress, training level, and memory systems in birds.
ano.nymous@ccsd.cnrs.fr.invalid (Flore Lormant) 23 Aug 2023
https://hal.science/hal-03369464v1
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[hal-03173757] Working for food is related to range use in free-range broiler chickens
When animals prefer to make efforts to obtain food instead of acquiring it from freely available sources, they exhibit what is called contrafreeloading. Recently, individual differences in behavior, such as exploration, were shown to be linked to how prone an individual may be to contrafreeload. In this work, our main objective was to test whether and how individual differences in range use of free-range broiler chickens (Gallus gallus domesticus) were related to the individual motivation to contrafreeload. We also verified whether other behavioral variations could relate to range use. To that aim, over three different periods (before range access, first weeks of range access, and last weeks of range access), chickens with different ranging levels (low and high rangers) were submitted to a contrafreeloading test and had different behaviors recorded (such as foraging, resting, locomotion) in their home environment. During the contrafreeloading test, chickens were conditioned to one chamber presenting a foraging substrate and mealworms, while in the other chamber, mealworms were freely available on the floor. During testing trials, chickens had access to both empty chambers, and the time spent in each chamber was quantified. On average, low rangers preferred the chamber where mealworms were easily accessible (without the foraging substrate), while high rangers preferred the chamber where mealworms were accessible with difficulty, showing greater contrafreeloading. Out of ten behaviors recorded in chickens' home environment, foraging was the only one that differed significantly between our two ranging groups, with low rangers foraging, on average, significantly less than high rangers. These results corroborate previous experiences suggesting that range use is probably linked to chickens' exploratory trait and suggest that individual differences in free-range broiler chickens are present even before range access. Increasing our knowledge of individual particularities is a necessary step to improve free-range chicken welfare on the farm.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 18 Mar 2021
https://hal.inrae.fr/hal-03173757v1
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[hal-02937496] Emotionality modulates the impact of chronic stress on memory and neurogenesis in birds
Chronic stress is a strong modulator of cognitive processes, such as learning and memory. There is, however, great within-individual variation in how an animal perceives and reacts to stressors. These differences in coping with stress modulate the development of stress-induced memory alterations. The present study investigated whether and how chronic stress and individual emotionality interrelate and influence memory performances and brain neurogenesis in birds. For that, we used two lines of Japanese quail (Coturnix japonica) with divergent emotionality levels. Highly (E+) and less (E−) emotional quail were submitted to chronic unpredictable stress (CUS) for 3 weeks and trained in a spatial task and a discrimination task, a form of cue-based memory. E + and E− birds were also used to assess the impact of CUS and emotionality on neurogenesis within the hippocampus and the striatum. CUS negatively impacted spatial memory, and cell proliferation, and survival in the hippocampus. High emotionality was associated with a decreased hippocampal neurogenesis. CUS improved discrimination performances and favored the differentiation of newborn cells into mature neurons in the striatum, specifically in E+ birds. Our results provide evidence that CUS consequences on memory and neural plasticity depends both on the memory system and individual differences in behavior.
ano.nymous@ccsd.cnrs.fr.invalid (Flore Lormant) 14 Sep 2020
https://hal.inrae.fr/hal-02937496v1
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[hal-03150252] Personality traits modulate stress responses after enclosure change of captive capuchin monkeys (Sapajus libidinosus)
Husbandry procedures may cause behavioral and physiological changes to animals living in captivity. However, an individual's reaction is not uniform and may be related to different coping strategies. In this study, we analyzed whether and how 12 adult captive capuchin monkeys (Sapajus libidinosus) varying in four personality axes ('Feeding', 'Sociability', 'Exploration', and 'Activity') differed in their stress responses to an enclosure change. Behavioral data and fecal samples of the individuals were collected for two months before (97 h and 246 fecal samples) and 14 days after the enclosure change (52 h and 666 fecal samples). We used Akaike Information Criteria to select the best linear regression models having personality axes and the period after enclosure change as predictive factors and behaviors potentially indicative of stress (BPIS) and levels of fecal glucocorticoid metabolites (FGM) as the response variables. Best models indicate that specific personality axes acted as a buffer and improved individual stress coping, mainly at the physiological level. More sociable and more active individuals did not show the peak of FGM levels as that exhibited by their less sociable and less active counterparts on the first day of the enclosure change. The link between exploration and resilience to acute stress was less clear: more exploratory individuals showed an increase in FGM levels during the first week of enclosure change, while the less exploratory ones showed a later increase, during the second-week post-enclosure change, suggesting a lesser capacity to recover from stressful stimuli in these individuals. The results presented in this study build on growing literature showing that animals differ in their behavioral profiles and that these differences relate to resilience to environmental disturbances, which may impact individual survival and reproduction, resulting in less genetic diversity of captive colonies and increased issues related to research replicability. We argue that these interindividual differences must be considered in husbandry decisions and during research data collection for the sake of animal welfare and reliable science.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 17 Oct 2022
https://hal.inrae.fr/hal-03150252v1
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[hal-03140110] Range use is related to free-range broiler chickens’ behavioral responses during food and social conditioned place preference tests
Free-range broiler chickens usually show an uneven spatial utilization of an outdoor range. Due to behavioral and cognitive between-individual differences, some animals may be driven to associate food and conspecifics more strongly to the barn, causing them to be less prone to explore the range. In this study, we aimed to understand how broiler chickens with different ranging levels (low- and high-ranging chickens) would behave under conditioned place preference (CPP) test situations. We used two cohorts conditioned to two natural rewarding stimuli: food and social companions. In a two-chambered apparatus, one cohort (n = 31, 16 high-ranging, and 15 low-ranging chickens) was conditioned to one chamber that always contained a cup with a food reward (mealworms), while the cup in the other chamber was always empty. The same design was also used with the second cohort (n = 31, 15 high-ranging and 16 low-ranging chickens), although instead of food, the reward was the physical presence of two conspecifics. During the testing trials, the animals had access to both empty chambers, and the time spent in each chamber was quantified. For the first day of the food CPP test, both the high- and low-ranging chickens spent significantly more time in the conditioned chamber, where they had previously found mealworms. During the following extinction days, the animals showed a gradual loss of their learned preference, increasing their immobility in the apparatus. High-ranging chickens were more immobile than low-ranging chickens, however, as their number of trials without moving was significantly higher. Unexpectedly, during the first day of the social CPP test, only high-ranging chickens showed a place preference. An overall place preference was observed only on the second day, with no chamber preference during the extinction days. Our results suggest that whether and how a stimulus-reward association occurs for free-range chickens may also be dependent on individual differences and the nature of the reward (food or social). Since associative learning occurs on a daily basis for farmed animals and the way individuals learn or value the reward varies, this research advanced our knowledge of animal behavior and individual cognitive differences that can be highly beneficial in improving animals' living conditions; this new understanding will allow for a more individualized approach to rearing broiler chickens in outdoor systems.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 22 Aug 2022
https://hal.inrae.fr/hal-03140110v1
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[hal-03140125] Social motivation and the use of distal, but not local, featural cues are related to ranging behavior in free-range chickens (Gallus gallus domesticus)
Animals can navigate an environment relying on different sources of information, such as geometrical or featural cues. The favoring of one type of information over another depends on multiple factors, such as inter-individual differences in behavior and cognition. Free-range chickens present different range use patterns, which may be explained by behavioral and cognitive differences. However, how behavior, cognition, and range use intercorrelate is still poorly understood. In this work, we aimed to further understand possible differences in behavior and cognition between two groups of free-range broiler chickens: those who frequently explore their range ('high rangers') and those who prefer to stay in or near the barn ('low rangers'). Prior to range access, individual behavior was measured in open field-, emergence-, and social motivation tests. To investigate cognitive differences, we analyzed whether exploratory behavior was linked to different performances in the use of distal and local spatial cues during an orientation task. During the social motivation test, low rangers showed a higher inclination to be near conspecifics than did high rangers. Our orientation tests show that chickens preferred to orientate themselves using the local cues over the distal cues. Individual differences were only found for distal, but not for local, cue use suggesting that demanding tasks are more efficient in revealing individual cognitive differences. Our results suggest that considering variation in social motivation may allow a more comprehensive understanding of chicken range use. Our results also support the importance of incorporating multiple aspects of individual differences to understand individual reactions to its environment.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 12 Feb 2021
https://hal.inrae.fr/hal-03140125v1
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[hal-02622887] Uninhibited chickens: ranging behaviour impacts motor self-regulation in free-range broiler chickens (Gallus gallus domesticus)
Inhibiting impulsive, less flexible behaviours is of utmost importance for individual adaptation in an ever-changing environment. However, problem-solving tasks may be greatly impacted by individual differences in behaviour, since animals with distinct behavioural types perceive and interact with their environment differently, resulting in variable responses to the same stimuli. Here, we tested whether and how differences in ranging behaviour of free-range chickens affect motor self-regulation performance during a cylinder task. For this task, subjects must refrain from trying to reach a food reward through the walls of a transparent cylinder and detour to its open sides, as a sign of inhibition. Free-range chickens exhibited an overall low performance in the motor self-regulation task (31.33 +/- 13.55% of correct responses), however, high rangers showed significantly poorer performance than the low rangers (23.75 +/- 9.16% versus 40 +/- 12.90%, respectively). These results give further support to the impacts of individual behavioural differences on cognitive performances. This is the first demonstration to our knowledge of a relationship between exploratory tendencies and motor self-regulation for an avian species.
ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 26 May 2020
https://hal.inrae.fr/hal-02622887v1
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[hal-02629384] Relationship between ranging behavior and spatial memory of free-range chickens
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ano.nymous@ccsd.cnrs.fr.invalid (Vitor Hugo Bessa Ferreira) 26 Oct 2021
https://hal.inrae.fr/hal-02629384v1
