Applied Animal Behaviour Science最新文献

Abiotic factors can have notable effects on animal behaviour at both seasonal and daily time scales. Understanding these effects is a critical consideration in the management and welfare of animals in human care. Herein we evaluated social behaviour and space use patterns of an ex-situ all-male Nile crocodile (Crocodylus niloticus) group in relation to seasonal (month) and daily (temperature, humidity, precipitation, time of day) abiotic factors over two years. Our results suggest that abiotic factors have notable influences on Nile crocodile behaviour at both seasonal and daily time scales. Seasonal patterns of behaviour were distinct, particularly between winter-spring and summer. Agonism rates during winter-spring were twice that of those in summer. Wounding was low throughout the year; however, the odds of having a wound increased by at least a factor of six during the winter compared to all other seasons. Also, sociosexual behaviour was almost exclusively observed within three months during the winter-spring seasons. These changes suggest this ex-situ all-male group’s social structure was seasonally variable in a manner that appears similar to reproductive seasonal changes observed in in-situ crocodile populations. Additionally, the odds of a crocodile being in water were nearly five times greater in the summer than winter-spring, likely reflective of seasonal differences in thermoregulatory requirements. Daily atmospheric conditions had generally weaker influences on behaviour than season; however, notable changes were observed suggesting daily abiotic variation is an important consideration in crocodile management. For example, morning rates of agonism were 1.5 times greater than afternoon rates, and the odds of a crocodile being in water were 73 % greater in the morning than afternoon. Collectively, these findings emphasize that care and welfare decisions based on behavioural inference may be incomplete, or worse inaccurate, if abiotic influences are not considered.

Arena tests are used to address various research questions related to animal behavior and human-animal relationships; e.g. how animals perceive specific human beings or people in general. Recent advancements in computer vision, specifically in application of key point detection models, might offer a possibility to extract variables that are the most often recorded in these tests in an automated way. The objective of this study was to measure two variables in human-pig arena test with computer vision techniques, i.e. distance between the subjects and pig’s visual attention proxy towards pen areas including a human. Human-pig interaction tests were organized inside a test arena measuring 147 × 168 cm. Thirty female pigs took part in the arena tests from 8 to 11 weeks of age, for a total of 210 tests (7 tests per pig), each with a 10-min duration. In total, 35 hours of human-pig interaction tests were video-recorded. To automatically detect human and pig skeletons, 4 models were trained on 100 images of labeled data, i.e. two YOLOv8 models to detect human and pig locations and two VitPose models to detect their skeletons. Models were validated on 50 images. The best performing models were selected to extract human and pig skeletons on recorded videos. Human-pig distance was calculated as the shortest Euclidean distance between all key points of the human and the pig. Visual attention proxy towards selected areas of the arena were calculated by extracting the pig’s head direction and calculating the intersection of a line indicating the heads direction and lines specifying the areas i.e. either lines of the quadrangles for the entrance and the window or lines joining the key points of the human skeleton. The performance of the YOLOv8 for detection of the human and the pig was 0.86 mAP and 0.85 mAP, respectively, and for the VitPose model 0.65 mAP and 0.78 mAP, respectively. The average distance between the human and the pig was 31.03 cm (SD = 35.99). Out of the three predefined areas in the arena, pigs spend most of their time with their head directed toward the human, i.e. 12 hrs 11 min (34.83 % of test duration). The developed method could be applied in human-animal relationship tests to automatically measure the distance between a human and a pig or another animal, visual attention proxy or other variables of interest.

This review summarizes the status of the art of cow-calf relationships at birth and during lactation, including the physiological mechanisms throughout suckling/nursing and weaning which can impact on productive and reproductive parameters, social behaviour across the mother-offspring pairs, and the required positive cow-calf welfare approach in beef cattle. The time spent close to the calf after birth, latency to nurse, nursing time, grooming and vocalisations can be considered fair proxies of oxytocin release and maternal care during the neonatal period. Besides, maternal contact during the first days after parturition will be crucial to guarantee the adequate establishment of mother-offspring bonding and the correct social and emotional development of young calf in beef cattle. During lactation, restricted nursing systems have been demonstrated as cost-effective management alternatives to improve reproductive herd performance. As artificial weaning of calves is considered a significant stressor in the lives of beef cattle, the use of a fence-line or the two-step weaning have been proposed, although no clear benefits in reducing cow-calf distress have been found. Modelling the perspective from a productive to a welfare approach in a beef cattle system is required. The ability of cows and calves to engage in voluntary, self-generated and goal-directed behaviour must be considered in the design of tailored management practices that maintain the trade-off between animal performance, cow-calf interactions, and positive mental state. Likewise, social interactions may be considered as part of environmental optimization to provide cow-calf pairs with opportunities for positive experiences and improve cattle welfare. The Five Domains Model is proposed to develop welfare-orientated management strategies considering aspects such as maternal deprivation, behavioural stress and socio-emotional development in beef cattle. This holistic approach of mother-offspring bonding focused on nutrition (Domain 1), physical environment (Domain 2), health (Domain 3), behavioural interactions (Domain 4) and animal’s mental state (Domain 5) will help to improve management decisions and cow-calf welfare state. Some management recommendations and opportunities for future studies to deeply enlarge the welfare perspective in the dyad are discussed.

The study aimed to determine the role of the habituation process of crossbred beef calves to corral handling on their reactivity, welfare and performance. Thirty-nine calves aged 87.69 ± 19.93 days were randomly divided into two treatments according to their weight, sex, and reactivity, as follows: 1) calves habituated to corral handling (HAB, N = 21) and 2) calves not habituated to corral handling, control group (NHAB, N = 18). The habituation process to corral handling was performed for 15 minutes twice a week for two weeks to reduce the animals' flight distance from humans. Calves' reactivities were scored when keeping them inside a scale and a squeeze chute (by applying scores ranging from 1 to 5 in both situations) and by scoring the speed at which they exited the squeeze chute (1 = walking or 2 = trotting and running). The assessments of physiological (heart rate, respiratory rate, and rectal temperature) and performance (average weight gain and weaning weight adjusted to 205d) indicators were carried out before (d-10), just after (d17) and 150 days after finishing the habituation process (d150). Mixed linear models were used to evaluate the fixed effects of treatments, assessment moments, and sex on most dependent variables, except for flight speed, which was analyzed using the Chi-square test. The HAB calves showed lower reactivity scores in d17 and 150 than NHAB calves in both measurements, scale and squeeze chute. Furthermore, a higher percentage of HAB calves exited the squeeze chute walking than NHAB calves in d17 and d150 (62 % vs 11 % and 24 % vs 5 %, respectively). None of the physiological variables was affected significantly by treatments. HAB calves showed greater ADG (p=0.0007) and reached a higher adjusted weaning weight to 205d (p=0.004) than NHAB calves. In conclusion, habituation to corral handling reduces reactivity and improves the performance of crossbred beef calves.

It is thought horses lack the prospection and brain architecture required for goal-directed, reflective model-based learning which considers future states. We investigate whether horses can use model-based strategy in an inhibitory task. Twenty subjects were trained for three sessions of a Stop-Signal paradigm using positive reinforcement (+R) for correct responding. All twenty failed to reach learning criterion. Subjects continued to touch in “Stop” contingencies indicating horses either: cannot complete Stop-Signal tasks; need further consolidation; or are utilising model-based cost-benefit analysis. Subjects underwent a further three sessions with the addition of negative punishment (+R/-P) as a cost for errors of emission (EE). If horses lack the ability to complete Stop-Signal tasks, EE would remain high across both treatments. If horses found Stop-Signal difficult but the introduction of cost aided their learning, EE would gradually decrease throughout the +R/-P condition. If horses built a cognitive model of the task but developed a strategy of indiscriminate responding in the +R condition, EE would suddenly decrease with the introduction of cost. A significant, immediate reduction in EE was observed when cost was introduced (p=0.02) that remained stable throughout the +R/-P condition providing evidence consistent with model-based cost-benefit analysis in horses.

Access to outdoor runs for small groups of fattening pigs, particularly in organic farming systems, are applied in practice and has been the subject of several studies. Access to an outdoor run has been shown to improve the welfare of pigs. However, little is known about the use of outdoor runs in large groups of up to 450 pigs. The aim of this study was to examine the usage of an outdoor run with restricted access in such a large group housing system, which involved using an indoor ventilation system when outdoor run access was restricted. A total of 900 pigs kept in two large groups of 450 pigs each were observed during the fattening period. Access to the outdoor run was provided by computer-controlled gates programmed to open at regular intervals during the day between 7:00 a.m. and 6:00 p.m. Opening phases of the gates to the outdoor run were signalled by a visual-acoustic signal. Restriction to the outdoor run was only on the way out, while access from the outdoor run to the inside area was continuously available. In addition to investigating the usage of the outdoor run, we also examined whether the pigs reacted to the visual-acoustic signals indicating the opening of the gates and whether the opening phases caused crowding in front of the gates. Furthermore, we evaluated the soiling of both the indoor area and the outdoor run. In these large group housing systems, the fattening pigs used the outdoor run continuously during the day, despite the restricted access. On average, 13.6 % of the fattening pigs were present in the outdoor run. No crowding, i.e., exaggerated accumulation of pigs, was observed at the gates during the opening phases. The fattening pigs mainly soiled two areas: an outdoor area near the fence and an uncovered lying area inside the barn. Our results from two large groups of pigs revealed, for the first time, important insights into how such groups use outdoor runs and automated gates.

New Zealand’s kea parrot (Nestor notabilis) is a highly neophilic species that is attracted to human settlements and structures. These environments pose several risks to this endangered species, but also pose a management challenge in how to best ensure that a neophilic species is kept away from the allure of ever-changing human environments. One possible mitigation strategy is the implementation of “kea jungle gyms” to provide kea with a potentially safer alternative to novelty, but little is known about how to design these structures to their fullest potential. In this study, we presented kea with samples of various materials to determine both what materials and their properties kea prefer to interact with, and which materials kea are least likely to engage with. We found that kea spent longer interacting with wood and some polymer plastics, and the least time interacting with hard metals, such as steel and stainless steel. These findings are discussed in the context of generating safe and effective management strategies that can be implemented for wild kea populations in the future, particularly with regard to appropriate designs of jungle gyms to encourage kea away from human settlements.

Objectives

The critical socialisation period for kittens is estimated to be 2–7 weeks of age. Kittens reared in shelters often have poorer outcomes due to high rates of infectious disease. Therefore, many shelters are reliant on foster care programs to improve kitten survival rates and behaviour. However, little is known about the impact of specific early socialisation factors on kitten behaviour and health.

Methods

During a 23-month period, 598 kitten foster carers completed a kitten socialisation questionnaire. The relationships between kitten weight/age at intake, days in care, singleton status, and the presence or absence of the queen during care on kitten behaviour and disease incidence were explored. Associations with exposure to noise, adults, children, location where the kitten was kept in the home, time spent alone, and ringworm treatment were also investigated.

Results

Overall being kept in social areas of the house with less noise/activity and spending some time alone was associated with positive kitten behaviour. There was no difference in fear or anxiety responses for bottle fed kittens, singletons and those without the queen. Ringworm treatment was associated with more fearful behaviour in kittens.

Conclusions

and relevance: Future foster carers should be encouraged to keep kittens in social areas of the house, whilst also ensuring kittens can spend some time alone. If the home is loud, carers should slowly introduce the kitten/s to the louder and busier areas of the house before being housed there all the time. Training of carers to use more positive reinforcement techniques for administering ringworm treatment may benefit kitten behaviour.

Gastrointestinal (GI) parasitism is a health and production concern in sheep, yet its impact on animal welfare remains unclear. The impact of subclinical infections is especially ambiguous as GI parasitism often remains undiagnosed until clinical signs such as diarrhoea are evident. This study applied quantitative and qualitative methods to examine the effects of subclinical Teladorsagia circumcincta infection on the behaviour and welfare of 96 Suffolk-cross lambs (24 pens of 4 lambs) weaned at 10 weeks old. The hypothesis that parasitism causes negative affective states was tested. Lambs were divided into three groups at the pen level: ad-lib fed control (AC), restricted-fed control (RC), and ad-lib fed parasitised (AP). Parasitised lambs (AP) were dosed three times weekly with 7000 third stage T. circumcincta larvae (L₃) from 16 weeks of age. Lambs in the RC group were pair fed to match AP feed intake to separate the effects of infection-induced anorexia from the potential direct impacts of infection. From 7 days pre-infection to 23 days post-infection, scan and behaviour samples were taken from video recordings to quantitatively monitor behaviour, and animal-based measures such as faecal soiling score (FSS) were recorded as welfare indicators. Lying, standing, eating, play and social behaviour were monitored. Qualitative behaviour assessment (QBA) was conducted weekly using the AWIN (2015) protocol to gain insight into the lambs’ affective states over the onset of infection. Parasitised lambs were more likely to stand inactive than AC lambs as the infection progressed (P=0.006). They were also less likely to display eating behaviour in the third daily scan sample than RC lambs (P<0.001). Principal Component Analysis of the QBA data revealed that the first dimension (PC1) described arousal levels, the second (PC2) described the valence of the animals’ affective states, and the third (PC3) described fearfulness and aggression levels. Parasitised lambs (est=10.64,SE=0.33) scored higher than RC lambs (est=9.42, SE=0.33) on PC3, the fearfulness dimension (P=0.030). There were no differences between fearfulness scores of AC and AP lambs or RC lambs and treatment group had no significant impact on the distribution of scores on PC1 or PC2. These findings demonstrate that subclinical GI parasitism negatively impacts lamb welfare not only in the health domain but in the behaviour and mental domains as well. This has implications for welfare assessments and early disease detection in lambs. Future research could explore remote monitoring of the indicators of parasitism identified in this study.