Search

Judgment bias tasks (JBTs) are considered as a family of promising tools in the assessment of emotional states of animals. JBTs provide a cognitive measure of optimism and/or pessimism by recording behavioral responses to ambiguous stimuli. For instance, a negative emotional state is expected to produce a negative or pessimistic judgment of an ambiguous stimulus, whereas a positive emotional state produces a positive or optimistic judgment of the same ambiguous stimulus. Measuring an animal's emotional state or mood is relevant in both animal welfare research and biomedical research. This is reflected in the increasing use of JBTs in both research areas. We discuss the different implementations of JBTs with animals, with a focus on their potential as an accurate measure of emotional state. JBTs have been successfully applied to a very broad range of species, using many different types of testing equipment and experimental protocols. However, further validation of this test is deemed necessary. For example, the often extensive training period required for successful judgment bias testing remains a possible factor confounding results. Also, the issue of ambiguous stimuli losing their ambiguity with repeated testing requires additional attention. Possible improvements are suggested to further develop the JBTs in both animal welfare and biomedical research.

Behavioral testing constitutes the primary method to measure the emotional states of nonhuman animals in preclinical research. Emerging as the characteristic tool of the behaviorist school of psychology, behavioral testing of animals, particularly rodents, is employed to understand the complex cognitive and affective symptoms of neuropsychiatric disorders. Following the symptom-based diagnosis model of the DSM, rodent models and tests of depression and anxiety focus on behavioral patterns that resemble the superficial symptoms of these disorders. While these practices provided researchers with a platform to screen novel antidepressant and anxiolytic drug candidates, their construct validity-involving relevant underlying mechanisms-has been questioned. In this review, we present the laboratory procedures used to assess depressive- and anxiety-like behaviors in rats and mice. These include constructs that rely on stress-triggered responses, such as behavioral despair, and those that emerge with nonaversive training, such as cognitive bias. We describe the specific behavioral tests that are used to assess these constructs and discuss the criticisms on their theoretical background. We review specific concerns about the construct validity and translational relevance of individual behavioral tests, outline the limitations of the traditional, symptom-based interpretation, and introduce novel, ethologically relevant frameworks that emphasize simple behavioral patterns. Finally, we explore behavioral monitoring and morphological analysis methods that can be integrated into behavioral testing and discuss how they can enhance the construct validity of these tests., (© 2024. The Author(s).)

Simple Summary: People's attitudes toward wild animals spark discussions and influence decision-making in wildlife research and conservation. One of the strongest and most consistent predictors of attitudes toward animal use is whether people believe that animals have thoughts and feelings. This study looked at how conservationists view the mental abilities of the animals they work with. Responses from 87 participants followed a general pattern, where larger and more complex animals, like mammals, were seen as having more advanced mental abilities than smaller animals, like insects. However, some exceptions to this pattern were found, suggesting that other factors, such as an animal's attributes, its role in human life, cultural influences, or scientific information, shape these perceptions. Human perceptions of animal consciousness have evolved over time, influencing how they are treated. This study aimed to assess perceptions of animal consciousness in people working in conservation. An online survey of 87 participants evaluated their perceptions of animals' capabilities across 10 dimensions of consciousness, including self-consciousness, learning, and reasoning. The sum of the answers to the questions was validated as a "perception index" using a principal component analysis. Next, its variation according to taxonomic, demographic, professional factors, and the duration, type, and frequency of interaction with animals was assessed with generalized linear models and stepwise model selection. Participants' perceptions varied with taxonomic class and the level of education, with mammals obtaining higher indexes than birds (−0.14; 95% confidence interval [CI] −0.24, −0.03, p < 0.01) or reptiles (−0.41; 95% CI −0.55, −0.27, p < 0.01), and respondents holding a PhD exhibiting higher perception indexes than those with BScs (−0.19; 95% CI −0.32, −0.06, p < 0.01) or lower education (−0.18; 95% CI −0.32, −0.03, p = 0.01). The attribution of consciousness followed a phylogenetic pattern, but several exceptions (e.g., the octopus and raven) were noted on a finer scale supporting a multifactorial influence on the perception of animal consciousness that emerges upon a baseline phylogenetic pattern. Finally, the results suggest that conservationists are influenced by culture and scientific knowledge, as much as their personal experiences, when evaluating animals' perceptions, highlighting the need for further research on the convergence between perception, belief, and evidence. [ABSTRACT FROM AUTHOR]

Various protocols to induce chronic stress in rodents are being used to determine the effects and underlying mechanisms of prolonged stress experience. Recently, a novel chronic social stress (CSS) protocol has been developed for mice where social instability in adolescence and early adulthood is induced. This protocol has been shown to cause an increase in HPA-axis activity and acute avoidance behaviour in the elevated plus maze. The aim of the present study was to investigate the effect of this CSS protocol on habituation to an initially novel environment in CD1 mice, since it has been shown that initially high avoidance behaviour in mice can still be followed by rapid habituation, pointing towards an adaptive response. One group of male mice, the CSS group, was exposed to the CSS protocol for 7 weeks and we compared their behavioural and physiological responses with male mice that were housed in a stable social group, the SH group. The results reveal a decrease in body weight gain and fur condition, changes in adrenal weight and decreased GR mRNA expression in the CA1 and the dentate gyrus of the hippocampus in chronically stressed CD1 animals. Irrespective of such evidence for a significantly stressful effect of the protocol, CD 1 mice, after termination of the stress procedure, revealed habituation profiles that matched those of control animals. We conclude that the physiological and central-nervous effects caused by a CSS procedure as used in this experiment fall within the coping capacities of CD1 mice at the behavioural level., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Safeguarding the welfare of animals is an important aim when defining housing and management standards in animal based, experimental research. While such standards are usually defined per animal species, it is known that considerable differences between laboratory mouse strains exist, for example with regard to their emotional traits. Following earlier experiments, in which we found that 129P3 mice show a lack of habituation of anxiety related behaviour after repeated exposure to an initially novel environment (non-adaptive profile), we here investigated four other 129 inbred mouse substrains (129S2/SvPas, 129S2/SvHsd (exp 1); 129P2 and 129X1 (exp 2)) on habituation of anxiety related behaviour. Male mice of each strain were repeatedly placed in the modified hole board test, measuring anxiety-related behaviour, exploratory and locomotor behaviour. The results reveal that all four substrains show a lack of habituation behaviour throughout the period of testing. Although not in all of the substrains a possible confounding effect of general activity can be excluded, our findings suggest that the genetic background of the 129 substrains may increase their vulnerability to cope with environmental challenges, such as exposure to novelty. This vulnerability might negatively affect the welfare of these mice under standard laboratory conditions when compared with other strains. Based on our findings we suggest to consider (sub)strain-specific guidelines and protocols, taking the (subs)train-specific adaptive capabilities into account.

Simple Summary: Anticipatory behaviour, which reflects animals' excitement or stress about upcoming rewards, is gaining attention in the assessment of animal welfare. This study looked at how horses' behaviour changes around feeding time, comparing horses on free-access (ad libitum) diets with those on limited (rationed) diets. Using video monitoring, researchers observed horses one hour before and after feeding over five days. The results showed that horses on restricted diets displayed more signs of stress and repetitive actions, especially as feeding time approached. These behaviours suggest that limiting food might cause feeding-related stress, which shows up in the horses' anticipation behaviours. The findings point to the need for thoughtful feeding practices in horse care to improve welfare, suggesting that monitoring these behaviours is an effective, low-cost way to keep track of animals' well-being over time. Anticipatory behaviour is increasingly being recognised as a measure of animal welfare. This behaviour is linked to reward sensitivity, which reflects the balance of positive and negative experiences. This study examined anticipatory behaviour in horses fed either ad libitum or rationed diets, aiming to identify differences in behaviour patterns during the periods of one hour immediately before and after feeding. Behavioural data were collected via video surveillance over five days, focusing on the pre- and post-feeding periods of stabled horses. The data were successfully fit to Poisson models. The results indicate that ration-fed horses exhibit more stereotypic and arousal behaviours, with anticipatory behaviour intensifying closer to feeding times. These findings suggest a potential link between feeding stress and anticipatory behaviour, especially in horses on rationed diets. This study underscores the importance of considering feeding practices in horse welfare management and highlights anticipatory behaviour as a valuable indicator for assessing animal well-being. Such assessments, rooted in circadian rhythms, offer a less resource-intensive means for ongoing welfare monitoring in animal care settings. [ABSTRACT FROM AUTHOR]

Copyright of Medizinische Klinik: Intensivmedizin & Notfallmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The emotional valence of animals is challenging to assess, despite being a key component of welfare. In this study, we attempted to assess emotional valence through memory in 1- and 3-week-old piglets. It was hypothesized that piglets would spend less time in a pen where they experienced a negative event (castration) and more time in a pen where they experienced a positive event (enrichment). A testing apparatus was designed with three equally sized pens: two outer sections serving as treatment pens containing unique visual and tactile cues and a center section remaining neutral. Piglets received either negative or positive condition in one outer treatment pen and a sham treatment in the opposite. Various methods were tested (age of piglets, number and length of conditioning sessions, passive vs. active conditioning). Contrary to expectations, piglets did not decrease their time in the pen associated with the negative condition or increase their time in the pen associated with the positive condition. However, when exposed to the positive condition, results indicate older piglets developed an aversion towards the sham treatment. This study provides methodological groundwork for the application of place conditioning in piglets and highlights the nuances important for the use of cognitive tests to assess animal welfare. [ABSTRACT FROM AUTHOR]

Spatial judgement bias tests (JBTs) can involve teaching animals that a bowl provides a reward in one location but does not in another. The animal is then presented with the bowl placed between the rewarded and the unrewarded locations (i.e., ambiguous locations) and their latency to approach reflects expectation of reward or 'optimism'. Some suggest that greater 'optimism' indicates better welfare. Performance in JBTs, however, may also indicate a learning history independently from welfare determinants. We hypothesized that dogs' 'optimism' in a follow-up JBT may be impacted by a learning treatment involving additional trials of a different discrimination task. Once enrolled, companion dogs (n = 16) were required to complete three study phases: (1) a pre-treatment JBT, (2) a learning treatment, and (3) a post-treatment JBT. During the JBTs, dogs were presented with five locations: one rewarded, one unrewarded, and three ambiguous (all unrewarded). Dogs were randomly assigned to a trial-based learning task—a nose-touch to the palm of the hand. In the Experimental discrimination treatment phase (n = 8), dogs were presented with two hands in each trial and only rewarded for touching one specific hand. In the Control treatment phase (n = 8), dogs were presented with one hand per trial in alternating sequence and were yoked to dogs in the Experimental group to receive the same number of rewarded and unrewarded trials (to control for possible frustration). Using a repeated measures mixed model with JBT repeated within dog, we found no difference in the change in approach latency to the ambiguous locations between the dogs across treatments. 'Optimism' as measured in this JBT was not altered by the additional discrimination trials used in our study. [ABSTRACT FROM AUTHOR]

To ensure good welfare of animals in human hands, it is essential to modify housing conditions according to the animals’ needs. Traditionally, the effects of such modifications are studied by means of group-level comparisons, thereby widely neglecting consistent inter-individual differences (i.e., so-called ‘animal personalities’). However, as animals with distinct personality types might differ in their environmental needs and hence react differently to the same environment, such systematic inter-individual differences might have important welfare consequences. This becomes particularly apparent under laboratory conditions, where animals are typically housed under highly standardized and barren environments. Against this background, we here aim to investigate personality-dependent welfare consequences in response to different housing conditions in laboratory mice. Female C57BL/6J mice were characterized for their personality type in exploration behavior and the most and the least explorative individuals were set up in either simple or in highly complex housing conditions that included constantly changing environmental enrichment items. We monitored individual welfare by studying behavioral, physiological, and immunological outcome measures. Besides personality dependent differences in immune parameters and overall improved welfare under complex housing conditions, we indeed found hints that individual mice were differently affected in their welfare depending on the specific combination of personality type and housing condition. Specifically, highly explorative mice appeared to be more adversely affected by simple housing, but also profited more from complex housing compared to low explorative mice. These findings indicate that welfare promoting adjustments do not necessarily benefit all individuals equally and therefore, call for a shift of perspectives in the evaluation of animal welfare. [ABSTRACT FROM AUTHOR]

Introduction: Dehorning calves is necessary to minimize injury because intensive raising circumstances make horned cows more aggressive. However, acute pain is commonly perceived by farm animals when undergoing painful practices such as dehorning, affecting their health status and quality of life. By quantifying the magnitude of pain and discomfort associated with dehorning, we aim to contribute to a more humane and sustainable cattle farming industry. Methods: The objective of this study was to evaluate the behavioral, physiological, and emotional effects of acute dehorning pain in calves using two methods: dehorning cream and dehorning hot-iron.30 Holstein calves aged 4days were selected for the study. These calves were randomly assigned to two experimental groups based on the method of disbudding: dehorning cream (n = 15) and hot-iron dehorning (n = 15). Before and after dehorning, we evaluated their physiological indicators of infrared eye temperature, concentrations of substance P, IL-6, cortisol, haptoglobin, as well as emotional state, and pain-related behavioral reactions. Results: Post-dehorning, the duration of lying down decreased significantly in both groups (DI and DC: 0-4h) after dehorning (p < 0.05). Both groups exhibited increased frequencies of pain-related behaviors such as head shaking (DI: 1-7h, DC: 1-6h), ear flicking (DI: 2-7h, DC: 2-7h), head scratching (DI: 2-3h, DC: 1-7h), and top scuffing (DI: 2h, DC: 2-7h) compared to pre-dehorning (p < 0.05). The DC group demonstrated a higher frequency of head-shaking, ear-flicking, headscratching, and top-rubbing behaviors, along with a longer duration of lying down (0-4h), compared to the DI group (p < 0.05). Post-dehorning, play behavior reduced significantly in both groups (6-8h) (p < 0.05), whereas judgment bias and fear levels showed no significant change (p > 0.05). Physiological measures including eye temperature, and blood levels of substance P and IL-6, did not differ significantly between the groups before and after dehorning (p > 0.05). However, 48h after dehorning, calves in the DC group had significantly higher haptoglobin levels compared to the DI group (p = 0.015). Additionally, salivary cortisol levels in the DC group increased significantly at 3.5h and 7h post-dehorning (p = 0.018, p = 0.043). Discussion: Both hot-iron and cream dehorning induced pain in calves, as evidenced by increased pain-related behaviors, elevated salivary cortisol, and higher haptoglobin levels, alongside reduced positive behaviors. Notably, these effects were more pronounced in the DC group than in the DI group, suggesting that dehorning hot-iron may be a comparatively less stressful dehorning method for young calves. Moreover, the brief duration of pain response and weaker response to dehorning observed in 13-day-age calves in this study suggests that dehorning at younger ages may be more advisable and warrants further research. [ABSTRACT FROM AUTHOR]

Cognitive bias is defined as the influence of emotions on cognitive processes. The concept of the cognitive judgement bias has its origins in human psychology but has been applied to animals over the past 2 decades. In this study we were interested in determining if laterality and personality traits, which are known to influence learning style, might also be correlated with a cognitive bias in the three-spined sticklebacks (Gasterosteus aculeatus). We used the judgement bias test with the go/no-go procedure where fish were first trained to discriminate between a black and white card and, after reaching a minimum learning criterion, tested their response to an ambiguous card (grey). Optimistic subjects were expected to have a high expectation of reward associated with an ambiguous stimulus, whereas pessimistic subjects a high expectation of non-reward. We used an emergence and a mirror test to quantify boldness and laterality, respectively. We hypothesised that male, bolder and more strongly lateralized fish would be more optimistic than female, shy and less strongly lateralised fish. We found that males and more strongly lateralized fish were more optimistic than females and less strongly lateralized fish. In addition, bold males were more optimistic than shy males as we predicted, but females showed the opposite pattern. Finally, fish trained on the black colour card learned the training task faster than those trained on a white card. Our results indicate that both laterality and personality traits are linked to animals' internal states (pessimistic or optimistic outlooks) which likely has broad implications for understanding animal behaviour particularly in a welfare context. [ABSTRACT FROM AUTHOR]

Simple Summary: For humans, music is a powerful tool of emotional communication, conveying affective states and modulating physiological states in ways that can influence well-being. Understanding that emotionality is not an exclusively human trait, as it is also recognized in non-human species, it is natural to assume that the intrinsic power of music to modulate the psychophysiological state may be trans-specific. In this way, music can be a powerful tool for enriching the environment and improving the welfare of captive animals, especially farm animals. As there is very limited information on non-human animals, the aim is to review what is known from a human comparative perspective, arguments that support its use, and the potential to use music in non-human species. The effects of sound stimulation as a sensorial environmental enrichment for captive animals have been studied. When appropriately implemented for farm animals, it can improve welfare, health, and productivity. Furthermore, there are indications that music can induce positive emotions in non-human animals, similar to humans. Emotion is a functional state of the organism involving both physiological processes, mediated by neuroendocrine regulation, and changes in behavior, affecting various aspects, including contextual perception and welfare. As there is very limited information on non-human animals, the objective of this review is to highlight what is known about these processes from human biological and comparative perspectives and stimulate future research on using music to improve animal welfare. [ABSTRACT FROM AUTHOR]

Most wild parrot species live in flocks, enriched by the environment and conspecific interactions. Captive parrots often live individually and are prone to behavioral maladaptation. If captive parrots and their behavior become intolerable, they are commonly relinquished to rescue organizations. This study aims to create parrot personality assessments for use by rescuers adding newly acquired parrots to shared environments. The study involved 20 orange-winged Amazon parrots (10 M, 10 F). Observers familiar with each bird scored its personality and analyses determined three sets of personalities: Social, Guarded, and Nervous Each parrot was paired with its 10 heterosexual counterparts and its interactions monitored remotely and captured on video. Pairing trials occurred over 72 hours in a specially designed pairing structure. Parrot personality could predict pairing success. Social-Guarded and Social-Nervous were more successfully paired, with individuals maintaining a close distance to one another and displaying increased rest-stretch behavior. Time of day influenced success with Social-Nervous pairs successful at all times of day, Social-Social pairs in the AM, and Guarded-Guarded pairs in the PM period. The study results suggest that rescues can use personality assessment and specific behaviors during cohabitation to predict OWA novel pairing outcomes. [ABSTRACT FROM AUTHOR]

Since Tinbergen’s seminal contribution in 1963, ethology has blossomed as a multifaceted research field. Sixty years later, uncountable articles followed the four questions proposed as necessary for understanding animal behaviour, and they culminated in the segmentation of subareas which communicate little among themselves. Foraging in ants is one example where this division happened, despite the clear need to integrate results obtained from different approaches. We chose this research subject to revise the literature, relating the main results to the relevant level of explanation in Tinbergen’s four questions theoretical framework. Through such revision, we aim to foster the integration of different approaches and to bring to light how this can clarify how we understand foraging behaviour, sixty years after Tinbergen’s initial proposition. [ABSTRACT FROM AUTHOR]

At a time when there is a growing public interest in animal welfare, it is critical to have objective means to assess the way that an animal experiences a situation. Objectivity is critical to ensure appropriate animal welfare outcomes. Existing behavioural, physiological, and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes. But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal, from negative to positive. In this review, we draw from the knowledge of human biomedical science to propose a list of candidate biological markers (biomarkers) that should reflect the experiential state of non-human animals. The proposed biomarkers can be classified on their main function as endocrine, oxidative stress, non-coding molecular, and thermobiological markers. We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life. [ABSTRACT FROM AUTHOR]

During the learning process, music can activate important neural areas in the brain, promoting the retention of information and memory formation. However, studies testing music effects on memory had found different improvements, which could be due to the methodological differences across studies. Thus, the purpose of this article was to systematically review the literature and meta-analyze the effects of music on Rattus norvegicus' explicit memory (Maze tests) only in controlled investigations. The seven studies included led to a very homogeneous analysis (I2 = 0%), confirming the consistency of the significant standardized mean difference (SMD) between the memory of animals exposed and not exposed to music (SMD 0.60 (95% CI 0.38; 0.83, p < 0.001)). Exploratory analysis suggests music benefits on memory can be acquired when begun at any age, when tested with the three types of mazes evaluated, with exposure lasting from 8 to 83 days and when the age on test day was either under 30 days or over 30 days. To expand the actual understanding of music effects on memory, future studies should investigate different types of music and animal species, with different sex and health conditions, at different time points. [ABSTRACT FROM AUTHOR]

Originating from human psychology, the concepts of "optimism" and "pessimism" were transferred to animal welfare science about 20 years ago to study emotional states in non-human animals. Over time, "optimism" and "pessimism" have developed into valuable welfare indicators, but little focus has been put on the ecological implications of this concept. Here, we aim to bridge this gap and underline the great potential for transferring it to behavioural ecology. We start by outlining why "optimism" and "pessimism" can be considered as aspects of animal personalities. Furthermore, we argue that considering "optimism"/"pessimism" in a behavioural ecology context can facilitate our understanding of individual adjustment to the environment. Specifically, we show how variation in "optimism"/"pessimism" can play a crucial role in adaptation processes to environmental heterogeneity, for example, niche choice and niche conformance. Building on these considerations, we hypothesise that "optimists" might be less plastic than "pessimists" in their behaviour, which could considerably affect the way they adjust to environmental change., (© 2024 The Author(s). Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.)

Background: The importance of music in intensive care medicine is still controversial and the mechanisms of music are unclear. It is important whether different music styles (classical music [CM], Heavy Metal [HM] show measurable effects on blood pressure (BP) or heart rate (HR) in humans or not. It is also unclear whether behavioral patterns are influenced by music (CM, HM) in animals., Methods: We studied the influence of CM (Bach, Orchestral Suite No. 3, BWV 1068) and HM (Band Disturbed: Indestructible) compared to a control group (CO) without music exposure in 120 healthy subjects (60 study subjects, 60 control subjects) and 36 young pigs (18 Pietrains, 18 Wiesenauer Minipigs) according to an identical study protocol (21 minutes of music exposure (CM, HM) or 21 minutes of no music (C0)., Results: We were able to clearly demonstrate in 36 pigs that CM led to significantly more activity behavior than HM or CO (p<0,01). HM caused significantly more stress behavior than CM or CO (p<0,01). In humans, there was a decrease in BP syst , BP diast or HR (beats per minute [bpm]) among CM: decrease BP syst -7,5±9,1 mm Hg, BP diast -4,9±7,5 mm Hg, HR -7,2±10,2 bpm. This was observed less frequently in HM: BP syst -3,6±7,1 mm Hg, BP diast -2,7±6,9 mm Hg, HR -5,9±9,0 bpm. The influence of BP and HR was significantly lower in CO compared to music: BP syst -2,3±7,2 mm Hg, BP diast -2,0±7,3 mm Hg, HR -5,8±12,3 bpm., Conclusions: BP and HR in humans and behavioral patterns in animals are clearly influenced by music. CM leads more frequently to activity behavior in animals and to lower BP and HR in humans compared to HM or CO. In both animal breeds, stress behavior was observed more frequently in HM compared to CM or CO. Therefore, music may play a role in intensive care medicine., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Affective state can bias an animal's judgement. Animals in positive affective states can interpret ambiguous cues more positively ("optimistically") than animals in negative affective states. Thus, judgement bias tests can determine an animal's affective state through their responses to ambiguous cues. We tested the effects of environmental complexity and stocking density on affective states of broiler chickens through a multimodal judgement bias test. Broilers were trained to approach reinforced locations signaled by one color and not to approach unreinforced locations signaled by a different color. Trained birds were tested for latencies to approach three ambiguous cues of intermediate color and location. Broilers discriminated between cues, with shorter latencies to approach ambiguous cues closest to the reinforced cue than cues closest to the unreinforced cue, validating the use of the test in this context. Broilers housed in high-complexity pens approached ambiguous cues faster than birds in low-complexity pens-an optimistic judgement bias, suggesting the former were in a more positive affective state. Broilers from high-density pens tended to approach all cues faster than birds from low-density pens, possibly because resource competition in their home pen increased food motivation. Overall, our study suggests that environmental complexity improves broilers' affective states, implying animal welfare benefits of environmental enrichment., (© 2021. The Author(s).)

Simple Summary: In intensive swine production systems, managing the regrouping of pigs is a common practice, but it often leads to aggressive behaviors, which can harm the welfare of the animals. This study explores an approach that involves composing and producing music based on acoustic parameters established by QUIRON Pathobiology research group. The aim is to reduce aggressive behaviors in pigs, thereby enhancing pig welfare during regrouping. Our findings indicate that this cost-effective and easy-to-implement strategy reduces aggressive behaviors in piglets during regrouping. This research offers valuable insights for producers, providing them with a practical way to enhance pig behavior and welfare while also contributing to the broader understanding of animal well-being in swine production systems. In intensive swine production systems,, the practice of regrouping unfamiliar pigs is common, often leading to aggressive behavior. Although the effect of different musical genres composed for humans has been evaluated in pigs to mitigate aggression, there have been few attempts to create music specifically for pigs. Here, we assess whether sensory stimulation through music, created by adapting the acoustic parameters in the sound mix, induces changes in the aggressive behaviors of pigs during regrouping. Six litters of 10-week-old piglets were randomly selected and assigned to different treatments. The control group (Group A) received no intervention, while Group B was exposed to music for two continuous hours in the morning and afternoon from the time of regrouping. Group C received musical stimulation for one continuous hour in the morning following regrouping. A significant reduction in the frequency and duration of aggressive behaviors was observed in the groups that received musical stimulation during regrouping. Additionally, social, and individual play behaviors showed a decrease in the musical stimulation groups. These findings provide evidence for the effectiveness of created music as a strategy in reducing aggressive behavior during pig regrouping, which can enhance the welfare of pigs and offer a practical solution for pig producers to minimize aggression and its associated negative impacts. [ABSTRACT FROM AUTHOR]

Background and purpose: Previous research has found that the electrical stimulation of the ventral tegmental area (VTA) is involved in drug-dependent behaviors and plays a role in reward-seeking. However, the mechanisms remain unknown, especially the effect of electrical stimulation on this area. Therefore, this study aimed to investigate how the electrical stimulation and the temporary inactivation of VTA affect the morphine- dependent behavior in male rats. Experimental approach: The adult Wistar male rats were anesthetized with ketamine and xylazine. The stimulation electrode (unilaterally) and the microinjection cannula (bilaterally) were implanted into the VTA, stereotaxically. Then, the rats underwent three-day of repeated conditioning with subcutaneous morphine (0.5 or 5 mg/kg) injections, in the conditioned place preference apparatus, followed by four-day forced abstinence, which altered their conditioning response to a morphine (0.5 mg/kg) priming dose on the ninth day. On that day, rats were given high- or low-intensity electrical stimulation or reversible inactivation with lidocaine (0.5 pL/site) in the VTA. Findings/Results: Results showed that the electrical stimulation of the VTA with the high intensity (150 μA/rat), had a minimal effect on the expression of morphine-induced place conditioning in rats treated with a high dose (5 mg/kg) of morphine. However, the reversible inactivation of the VTA with lidocaine greatly increased place preference in rats treated with a low dose (0.5 mg/kg) of morphine. Additionally, the reinstatement of 0.5 mg/kg morphine-treated rats was observed after lidocaine infusion into the VTA. Conclusion and implications: These results suggest that VTA electrical stimulation suppresses neuronal activation, but the priming dose causes reinstatement. The VTA may be a potential target for deep brain stimulation-based treatment of intractable disorders induced by substance abuse. [ABSTRACT FROM AUTHOR]

Simple Summary: Environmental enrichment to improve animal welfare has been receiving growing attention. The effect of auditory stimulation as a method of environmental enrichment is unclear for the behavior and welfare of chicks. In this study, one-day-of-age chicks were exposed to different auditory environments. The behavior, learning ability, and fearfulness of the chicks were examined to explore the effect of different auditory environments on the behavior and welfare of chicks. The findings confirmed that music stimulation of 65–75 dB had positive effects in reducing fearfulness, and music and noise of 85–95 dB reduce the expression of comforting and preening in chicks, impairing their learning ability, and increasing the level of fearfulness. Environmental enrichment can improve animal welfare. As a method of environmental enrichment, the effect of different auditory stimulations on the behavior response and welfare of laying hen chicks has yet to be investigated. Therefore, this study was aimed at exploring the impact of various auditory exposures on the behavior, learning ability, and fear response of 4-week-old laying hen chicks. A total of 600 1-day-old chicks were randomly assigned to five different groups: C (control group), LM (Mozart's String Quartets, 65 to 75 dB), LN (recorded ventilation fans and machinery, 65 to 75 dB), HN (recorded ventilation fans and machinery, 85 to 95 dB), and HM (Mozart's String Quartets, 85 to 95 dB). The experiment was conducted from day 1 until the end of the experiment on day 28. Groups LM and LN were exposed to music and noise stimulation ranging from 65 to 75 dB. Groups HN and HM, meanwhile, received noise and music stimulation ranging from 85 to 95 dB. The control group (C) did not receive any additional auditory stimuli. During the experimental period, continuous behavioral recordings were made of each group of chicks from day 22 to day 28. On day 21, the PAL (one-trial passive avoidance learning) task was conducted. On days 23 and 24, OF (open field) and TI (tonic immobility) tests were performed, and the levels of serum CORT (corticosterone) and DA (dopamine) were measured. The results indicated that exposure to music and noise at intensities ranging from 85 to 95 dB could reduce comforting, preening, PAL avoidance rate, the total number of steps and grid crossings of OF, and the concentration of DA in 4 WOA chicks (p < 0.05), increase the freezing times of OF (p < 0.05); 65 to 75 dB of noise stimulation could reduce preening and total number steps of OF in 4 WOA chicks (p < 0.05), increase the freezing times of OF (p < 0.05); and 65 to 75 dB of music exposure could reduce the concentration of CORT in 4 WOA chicks (p < 0.05). Therefore, 65 to 75 dB of music exposure could produce positive effects on chicks and showed relatively low CORT level, whereas 85 to 95 dB of music and noise exposure could reduce comforting and preening behavior, impair learning ability, and increase the fear responses of chicks. [ABSTRACT FROM AUTHOR]

Simple Summary: Greater awareness about animal welfare forces breeders to pay more attention to animals' needs and behaviors. The presence of sound coming from surroundings, machines, people, and animals themselves may be an important factor that affects animal welfare. If understood correctly, vocalization can provide valuable information about the emotional state of an animal, thus allowing situations to be adjusted to keep them comfortable. On the other hand, excessive noise can significantly affect the health and behavior of farm animals. If the sounds are outside the hearing range of humans, it becomes challenging to recognize their influence unless one has a deep understanding of how farm animals' hearing works. In summary, existing research provides promising insights into the connection between sounds and the welfare of farm livestock. While there are reports highlighting the harmful effects of noise on livestock, further research should focus on exploring this aspect in more detail. To ensure the optimal living conditions of farm animals, it is essential to understand how their senses work and the way in which they perceive their environment. Most animals have a different hearing range compared to humans; thus, some aversive sounds may go unnoticed by caretakers. The auditory pathways may act through the nervous system on the cardiovascular, gastrointestinal, endocrine, and immune systems. Therefore, noise may lead to behavioral activation (arousal), pain, and sleep disorders. Sounds on farms may be produced by machines, humans, or animals themselves. It is worth noting that vocalization may be very informative to the breeder as it is an expression of an emotional state. This information can be highly beneficial in maintaining a high level of livestock welfare. Moreover, understanding learning theory, conditioning, and the potential benefits of certain sounds can guide the deliberate use of techniques in farm management to reduce the aversiveness of certain events. [ABSTRACT FROM AUTHOR]

To perform quick assessments, welfare practitioners may focus on specific behavioral indicators of welfare, which can lead to challenges in interpretation. Anticipatory behavior has been suggested as a potentially graded indicator of well-being in animals. However, there are difficulties in assessing variations in this class of behavior quantitatively. Here, we propose an analytical approach for identifying and comparing the intensity of anticipatory behavior across different conditions. We evaluated the changes in the behavior of a sea lion at the San Francisco Zoo before and after daily training sessions, the start time of which had differing degrees of predictability. We show that anticipatory behavior is a complex suite of behaviors that can show multi-directional changes prior to an anticipated event. Additionally, we show that the methods utilized here can distinguish among differing intensities of anticipation directed toward daily husbandry events. We suggest that this approach may be broadly applicable for applying measures of anticipatory behavior as a graded welfare indicator. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effects of environmental enrichment for pigs during transportation in different phases of their productive cycle. Two trials were conducted, the first during transportation of pigs from the piglet production unit (PPU) to the nursery (n = 250) and the second during the transportation of nonhuman animals from the finishing unit (FU) to the slaughterhouse (n = 120). This work was an observational study with five environmental enrichments: Control – no enrichment; object – use of enrichment objects in the truck; aroma – use of lavender aroma in the truck; music – music in the truck; and vehicle sound. Animal behavior during transportation, respiratory rate, skin surface temperature, and skin lesion score were assessed. Piglets from the treatment music had the lowest frequency of agonistic behaviors during transportation from the farrowing to the nursery and lower skin temperature after transportation. Piglets from the control had the highest respiratory rate prior to transportation. Pigs familiarized with vehicle noises spent most of their time lying during the trip to the slaughterhouse. The creation of a familiar environment to pigs seems promising in enhancing animal well-being during transportation. [ABSTRACT FROM AUTHOR]

Current frameworks for designing and evaluating good enclosures and "enrichments" typically focus on animals' active interactions with these features. This has undoubtedly improved the welfare of zoo‐housed animals over the last 30 years or more. However, literature reviews from this same period identify persistent gaps in how such frameworks are applied: experiences and behaviors that do not rely on active interaction with stimuli or resources are largely ignored, when evaluating the welfare value of enclosures and enrichments within them. Here, we review research evidence demonstrating that active interaction is not always a reliable measure of welfare value, showing that items that elicit little or no interaction can nevertheless still reduce stress and improve well‐being. This evidence largely comes from research on humans, lab animals and farm animals, but also from some zoo studies too. We then investigate why. We review psychology and ethology literatures to show that such welfare benefits can arise from five, non‐mutually exclusive, processes or mechanisms that are well‐understood in humans and domestic animals: (1) some motivations are sated quickly by interaction with resources, yet still have large welfare benefits; (2) active interaction may just be a way to achieve a goal or solve a problem, without being beneficial for welfare in itself; (3) having opportunities for choice and control may be inherently beneficial, even when not acted on; (4) some enclosure features meet social needs for structure, landmarks, and blocked sightlines; and (5) some stimuli may be preferred because they signaled good environments to an animal's ancestors. We use this information to identify improved ways of enhancing and assessing zoo animal welfare. Incorporating these concepts should expand the scope of behaviors and subjective experiences that are targeted, to now include those that involve little active interaction and yet still are important for good welfare. Research Highlights: Interaction is often not a reliable measure of enrichment value or welfare benefit. Resources that elicit little interaction can still be highly valued and improve welfare. Understanding why can promote good enclosure design. [ABSTRACT FROM AUTHOR]

Bergamot essential oil shows anxiolytic-relaxant effects devoid of sedative action and motor impairment typical of benzodiazepines. Considering the potential for clinical of these effects, it is important to understand the underlying mechanisms of the phytocomplex. Modulation of glutamate group I and II metabotropic receptors is involved in stress and anxiety disorders, in cognition and emotions and increases locomotor activity and wakefulness. Interestingly, early data indicate that bergamot essential oil modulates glutamatergic transmission in specific manifestations of the central nervous system. The aim of this work is to investigate if selective antagonists of metabotropic glutamate 2/3 and 5 receptors affect behavioral parameters modulated by the phytocomplex. Male Wistar rats were used to measure behavioral parameters to correlate anxiety and motor activity using elevated plus maze (EPM), open field (OF), and rotarod tasks. Bergamot essential oil increases in EPM the time spent in open/closed arms and reduces total number of entries. The essential oil also increases immobility in EPM and OF and not affect motor coordination in rotarod. Pretreatment with the metabotropic glutamate antagonists does not affect the time spent in open/close arms, however, differently affects motor behavior measured after administration of phytocomplex. Particularly, glutamate 2/3 antagonist reverts immobility and glutamate 5 antagonist potentiates this parameter induced by the phytocomplex. Our data show that modulation of both metabotropic glutamate receptors is likely involved in some of behavioral effects of bergamot essential oil., (© 2024 The Authors. Phytotherapy Research published by John Wiley & Sons Ltd.)