Behavioural Welfare Indicators Research Articles

Effects of straw provision, as environmental enrichment, on behavioural indicators of welfare and emotions in pigs reared in an experimental system

The present study aimed to investigate whether straw provision in pigs increases positive emotions, indicated by tail movement, and reduces poor welfare indicators (agonistic and displacement behaviours), including indicators of negative emotions (ear movement). Comparisons between Straw and Control sessions were analysed from video recording for all parameters. 15 mini-pigs participated in a three-week study. Depending on the week, animals were included in Straw or Control sessions. During Straw sessions, pigs were placed in their own pens where straw was introduced and continuously provided for one week. During Control sessions, pigs remained in their pens with no additional stimulus. Pig behaviours were video-recorded four times during each session and scored. Results showed that ear movement frequency was significantly lower in the Straw than in Control session (p = 0.005); agonistic behaviour frequency and duration were significantly lower in the Straw than in Control session (p = 0.013 and p = 0.0004, respectively), and displacement behaviour frequency and duration were significantly lower in the Straw than in Control session (p < 0.001 and p = 0.01, respectively). Results suggest that straw provision reduces poor welfare but does not modify indicators of positive emotions selected for this study (tail movement frequency and duration). Our study also provides information about potential indicators of welfare, and more precisely, about emotions, which could also be useful to improve animal welfare assessment in pigs, obtaining more information about feasible behavioural indicators which could show the emotional state of the animals.

A Review of Welfare Assessment Methods in Reptiles, and Preliminary Application of the Welfare Quality® Protocol to the Pygmy Blue-Tongue Skink, Tiliqua adelaidensis, Using Animal-Based Measures.

Simple SummaryReptiles are commonly housed in wildlife parks and zoos, and are increasingly being kept as pets. Husbandry of reptiles is complex; signs of pain or disease can be challenging to recognize, and behavior is not always well understood. Therefore, assessment of reptile welfare may be difficult. In comparison to mammals, methods of welfare assessment in reptiles are under-investigated. In this paper we review the literature on welfare assessment techniques in reptiles. We determine that indicators of negative affective state are better characterized in reptiles, and are likely easier to apply in a welfare assessment tool. Indicators of positive affective state such as play behavior, and judgment bias experimental techniques, should be investigated further in reptiles. We also explore the application of the Welfare Quality® Protocol to the pygmy blue-tongue skink, an endangered species. This application presents examples of predominantly animal-based indicators that may be further investigated for use in a tool in this, and other reptile species.Reptiles are held at wildlife parks and zoos for display and conservation breeding programs and are increasingly being kept as pets. Reliable indicators of welfare for reptiles need to be identified. Current guidelines for the captive management of reptiles utilize resource-based, rather than animal-based indicators; the latter being a more direct reflection of affective state. In this paper we review the literature on welfare assessment methods in reptiles with a focus on animal-based measures. We conclude that, whilst a number of physiological and behavioral indicators of welfare have been applied in reptiles, there is need for further validation of these methods across the diversity of species within the Class. Methods of positive welfare state assessment are comparatively understudied and need elucidation. Finally, we examine some widely-used welfare assessment tools in mammals and explore the application of the Welfare Quality® Protocol to the endangered pygmy blue-tongue skink, Tiliqua adelaidensis. We propose that this framework can form the basis for the development of taxon-specific tools with consideration of species-specific biology.

Current Perspectives on Therapy Dog Welfare in Animal-Assisted Interventions.

Simple SummaryIn animal-assisted interventions (AAIs) animals are used as adjuncts to therapy to positively affect human health. The practice of implementing dogs into therapeutic environments is emerging and as a result, there has been a growing scientific interest on human health outcomes over the past decades. Research efforts into the canine perspective of AAIs have been scarce. Accordingly, there is little consensus on the impact of such interventions on the animals involved. This paper aimed to contribute to the limited body of knowledge by reviewing available studies on therapy dogs’ welfare during AAIs. Moreover, discussion of theoretical and methodological issues, implications for practice and suggestions for future research are provided.Research into the effects of animal-assisted interventions (AAIs) has primarily addressed human health outcomes. In contrast, only few publications deal with the therapy dog experience of AAIs. This paper provides an overview on potential welfare threats that therapy dogs may encounter and presents the results of a review of available studies on welfare indicators for therapy dogs during AAIs. Previous investigations used physiological and behavioral welfare indicators and dog handler surveys to identify work-related stress. Research outcomes are discussed in the light of strengths and weaknesses of the methods used. Study results suggest that frequency and duration of AAI sessions, novelty of the environment, controllability, age and familiarity of recipients modulate animal welfare indicators. However, this review reveals that currently, clear conclusions on how the well-being of dogs is influenced by the performance in AAIs are lacking due to the heterogeneity of programs, recipient and session characteristics, small dog sample sizes and methodological limitations. This paper further aimed to identify unresolved difficulties in previous research to pave the way for future investigations supporting the applicability of scientific findings in practice.

Can Sleep and Resting Behaviours Be Used as Indicators of Welfare in Shelter Dogs (Canis lupus familiaris)?

Previous research on humans and animals suggests that the analysis of sleep patterns may reliably inform us about welfare status, but little research of this kind has been carried out for non-human animals in an applied context. This study explored the use of sleep and resting behaviour as indicators of welfare by describing the activity patterns of dogs (Canis lupus familiaris) housed in rescue shelters, and comparing their sleep patterns to other behavioural and cognitive measures of welfare. Sleep and activity patterns were observed over five non-consecutive days in a population of 15 dogs. Subsequently, the characteristics of sleep and resting behaviour were described and the impact of activity on patterns of sleep and resting behaviour analysed. Shelter dogs slept for 2.8% of the day, 14.3% less than previously reported and experienced less sleep fragmentation at night (32 sleep bouts). There were no statistically significant relationships between behaviours exhibited during the day and sleep behaviour. A higher proportion of daytime resting behaviour was significantly associated with a positive judgement bias, less repetitive behaviour and increased time spent coded as ‘relaxed’ across days by shelter staff. These results suggest that, in the context of a busy shelter environment, the ability to rest more during the day could be a sign of improved welfare. Considering the non-linear relationship between sleep and welfare in humans, the relationship between sleep and behavioural indicators of welfare, including judgement bias, in shelter dogs may be more complex than this study could detect.

Does enrichment improve reptile welfare? Leopard geckos (Eublepharis macularius) respond to five types of environmental enrichment

Animal welfare is a high priority for pet owners and accredited zoos and aquariums. Current approaches to measuring welfare focus on identifying consensus among behavioral and physiological indicators of positive and negative emotions. Environmental enrichment is a common strategy used to improve the welfare of captive animals. In enrichment programs, knowledge of an animal’s ecology and individual history are applied to modify the animal’s current environment and management to increase environmental complexity, make the environment more functional or natural, and increase behavioral opportunities. While enrichment techniques for primates and large mammals are well-studied, reptile enrichment has received little attention to date despite a few promising studies. In this study, we monitored the responses of 16 leopard geckos to five types of enrichment (Thermal, Feeding, Olfactory, Object, and Visual) using a repeated-measures design. We measured both specific behaviors we expected to change in response to each enrichment type and four behavioral indicators of welfare: exploratory behavior, species-specific behaviors (behavioral thermoregulation and hunting), behavioral diversity, and abnormal repetitive behaviors. We found geckos interacted with all five types of enrichment at above-chance levels (i.e., no 95% CIs for engagement time overlapped with 0s). Geckos spent more time interacting with Thermal and Feeding enrichment than the other types (F(4,60)=49.84, p<0.001). Thermal, Feeding, Olfactory, and Object enrichments (but not Visual enrichment) changed specific relevant behaviors (e.g., Thermal enrichment altered thermoregulatory behaviors, Wilk’s lambda=0.25, F(3,13)=13.39, p<0.001) and improved behavioral indicators of welfare (e.g., behavioral diversity, Wilks’ lambda=0.30, F(12,178)=12.31, p<0.001). These results suggest that geckos respond to environmental enrichment, that their responses are predictable based on their ecology, and that environmental enrichment improves gecko welfare. As in mammals and birds, enrichments that address behavioral needs (here: thermoregulation and feeding) appear more effective than enrichments that simply provide novel stimuli to increase exploration. The extent to which our results can be generalized to other reptile species awaits further study, but we suggest that enrichment should be more widely used to improve reptile welfare.

Investigating the relationship between welfare and rearing young in captive chimpanzees (Pan troglodytes)

Whether the opportunity to breed and rear young improves the welfare of captive animals is currently debated. However, there is very little empirical data available to evaluate this relationship and this study is a first attempt to contribute objective data to this debate. We utilized the existing variation in the reproductive experiences of sanctuary chimpanzees at Chimfunshi Wildlife Orphanage Trust in Zambia to investigate whether breeding and rearing young was associated with improved welfare for adult females (N=43). We considered several behavioural welfare indicators, including rates of luxury behaviours and abnormal or stress-related behaviours under normal conditions and conditions inducing social stress. Furthermore, we investigated whether spending time with young was associated with good or poor welfare for adult females, regardless of their kin relationship. We used generalized linear mixed models and found no difference between adult females with and without dependent young on any welfare indices, nor did we find that time spent in proximity to unrelated young predicted welfare (all full-null model comparisons likelihood ratio tests P>0.05). However, we did find that coprophagy was more prevalent among mother-reared than non-mother-reared individuals, in line with recent work suggesting this behaviour may have a different etiology than other behaviours often considered to be abnormal. In sum, the findings from this initial study lend support to the hypothesis that the opportunity to breed and rear young does not provide a welfare benefit for chimpanzees in captivity. We hope this investigation provides a valuable starting point for empirical study into the welfare implications of managed breeding.

The use of acoustic acceleration transmitter tags for monitoring of Atlantic salmon swimming activity in recirculating aquaculture systems (RAS)

Successful operation of recirculating aquaculture systems is dependent on frequent monitoring of the optimal function of water treatment processes in order to maintain environmental conditions for optimal growth and welfare of the fish. Real time monitoring of fish status is however usually not an integrated part of automatized systems within RAS. The aim of this study was to evaluate the use of implanted acoustic acceleration transmitters to monitor Atlantic salmon swimming activity. Twelve salmon post-smolts were individually tagged and distributed in three tanks containing salmon at start density of 50kgm−3. The tagging did not cause any mortality and all individuals increased their body weight during this study. Following initial recovery, acceleration data were continuously logged for one month, including treatment periods with exposure to hyperoxic (170% O2 saturation) and hypoxic (60% O2 saturation) conditions, and different tank hydraulic retention times (HRT; 23 and 58min). Changes in-tank dissolved oxygen levels to hyperoxic and hypoxic conditions reduced the total activity of Atlantic salmon in this study. On the contrary, increased and reduced tank HRT increased the total activity levels. Feeding periods induced a sharp increase in the Atlantic salmon swimming activity, while irregular feeding caused larger oscillations in activity and also lead to increased swimming activity of the tagged fish. Atlantic salmon responded with a maximum recorded total activity to stress caused by technical problems within the system and consequent changes in the RAS environment. The results of this study indicate that Atlantic salmon respond quickly with changed swimming activity to changes in the water quality and acute stress caused by normal management routines within RAS. The use of acoustic acceleration transmitters for real time monitoring of swimming activity within aquaculture production systems may allow for rapid detection of changes in species-specific behavioural welfare indicators and assist in the refinement of best management practices. In addition, acceleration tag could potentially serve as a valuable research tool for behavioural studies, studies on stress and welfare and could allow for better understanding of interaction between fish and RAS environment.

Searching for behavioral indicators of welfare in zoos: uncovering anticipatory behavior.

A current focus of zoo-based research aims to identify indicators of animal welfare. Reliable behavioral indicators of welfare are highly desirable as behavioral observation is non invasive and requires little in the way of specialized equipment and other costly resources-save for observer time. Anticipatory behavior is an indicator of an animal's sensitivity to reward and as such, it is a real-time indicator of animals' own perceptions of their well-being. In fact, anticipatory behavior may generate a positive affective state and thus be at least a brief manifestation of good welfare itself. The husbandry conditions of most captive animals are such that food acquisition and other positive outcomes are highly scheduled and easily signaled. These conditions promote the development of anticipatory behavior, yet little research has either documented or interpreted this behavior in zoo and aquarium animals. This commentary suggests that anticipatory behavior could be a useful tool for assessing welfare and calls upon zoo and aquarium researchers to begin to develop this tool by describing the behavior and the circumstances that lead to its modulation.

Physiological, physical and behavioural changes in dogs (Canis familiaris) when kennelled: Testing the validity of stress parameters

Domestic dogs (Canis familiaris) housed in kennelling establishments are considered at risk of suffering poor welfare. Previous research supporting this hypothesis has typically used cortisol:creatinine ratios (C/Cr) to measure acute and chronic stress in kennelled dogs. However, the value of C/Cr as a welfare indicator has been questioned. This study aimed to test the validity of a range of physiological, physical and behavioural welfare indicators and to establish baseline values reflecting good dog welfare. Measurements were taken from 29 privately-owned dogs (14 males, 15 females), ranging in age and breed, in their own home and in a boarding kennel environment, following a within-subjects, counterbalanced design. Pairwise comparisons revealed that C/Cr and vanillylmandelic acid:creatinine ratios (VMA/Cr) were higher in the kennel than home environment (P=0.003; P=0.01, respectively) and were not associated with differences in movement/exercise between environments. Dogs' surface temperature was lower in kennels (P=0.001) and was not associated with ambient temperature. No association with age, or effects of kennel establishment, kennelling experience, sex or source were found. Dogs were generally more active in kennels, but showed considerable individual variability. C/Cr and 5-HIAA:creatinine ratios (5-HIAA/Cr) were negatively correlated with lip licking in kennels. Baseline values for each parameter are presented. The emotional valence of responses was ambiguous and no definitive evidence was found to suggest that dogs were negatively stressed by kennelling. It was concluded that C/Cr and, particularly, VMA/Cr and surface temperature provide robust indicators of psychological arousal in dogs, while spontaneous behaviour might be better used to facilitate interpretation of physiological and physical data on an individual level.

Behavioural indicators of welfare in farmed fish

Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in foraging behaviour, ventilatory activity, aggression, individual and group swimming behaviour, stereotypic and abnormal behaviour have been linked with acute and chronic stressors in aquaculture and can therefore be regarded as likely indicators of poor welfare. On the contrary, measurements of exploratory behaviour, feed anticipatory activity and reward-related operant behaviour are beginning to be considered as indicators of positive emotions and welfare in fish. Despite the lack of scientific agreement about the existence of sentience in fish, the possibility that they are capable of both positive and negative emotions may contribute to the development of new strategies (e.g. environmental enrichment) to promote good welfare. Numerous studies that use behavioural indicators of welfare show that behavioural changes can be interpreted as either good or poor welfare depending on the fish species. It is therefore essential to understand the species-specific biology before drawing any conclusions in relation to welfare. In addition, different individuals within the same species may exhibit divergent coping strategies towards stressors, and what is tolerated by some individuals may be detrimental to others. Therefore, the assessment of welfare in a few individuals may not represent the average welfare of a group and vice versa. This underlines the need to develop on-farm, operational behavioural welfare indicators that can be easily used to assess not only the individual welfare but also the welfare of the whole group (e.g. spatial distribution). With the ongoing development of video technology and image processing, the on-farm surveillance of behaviour may in the near future represent a low-cost, noninvasive tool to assess the welfare of farmed fish.

Does feeding time affect fish welfare?

Increased aquaculture production has raised concerns about managing protocols to safeguard the welfare of farmed fish, as consumers demand responsible aquaculture practices to provide 'welfare friendly' products. Feeding is one of the largest production cost in a fish farm and can be one of the biggest stressors for fish. Under farming conditions, fish are challenged with artificial diets and feeding regimes, and inadequate feeding conditions cause stress, alteration of normal behavioural patterns, poor performance and eventually diseases and death, which are by no means acceptable neither economically nor ethically. This review aims to highlight the impact of feeding rhythms and feeding time upon physiological and behavioural welfare indicators, which show circadian rhythms as well. Therefore, all these variables should be considered when designing feeding strategies in farming conditions and assessing the welfare state of cultured fish.

Relationships between behaviour and health in working horses, donkeys, and mules in developing countries

Recent studies raise serious welfare concerns regarding the estimated 93.6 million horses, donkeys and mules in developing countries. Most equids are used for work in poor communities, and are commonly afflicted with wounds, poor body condition, respiratory diseases, parasites, dental problems, and lameness. Non-physical welfare problems, such as fear of humans, are also of concern. Interventions to improve working equine welfare aim to prioritise the conditions that cause the most severe impositions on the animals’ subjectively experienced welfare, but data identifying which conditions these may be, are lacking. Here we describe a stage in the validation of behavioural welfare indicators that form part of a working equine welfare assessment protocol. Over 4 years, behavioural and physical data were collected from 5481 donkeys, 4504 horses, and 858 mules across nine developing countries. Behaviours included the animals’ general alertness, and their responses to four human-interaction tests, using the unfamiliar observer as the human stimulus. Avoidance behaviours correlated significantly with each other across the human-interaction tests, with 21% of animals avoiding the observer, but they showed no associations with likely anthropogenic injuries. Over 13% of equids appeared ‘apathetic’: lethargic rather than alert. Measures of unresponsiveness correlated with each other across the five tests, and were associated with poor body condition, abnormal mucous membrane colour, faecal soiling, eye abnormalities, more severe wounds, and older age, depending on the equine species. This suggests that working equids in poor physical health show an unresponsive behavioural profile, consistent with sickness behaviour, exhaustion, chronic pain, or depression-like states.

Recent advances in the analysis of behavioural organization and interpretation as indicators of animal welfare.

While the incorporation of mathematical and engineering methods has greatly advanced in other areas of the life sciences, they have been under-utilized in the field of animal welfare. Exceptions are beginning to emerge and share a common motivation to quantify 'hidden' aspects in the structure of the behaviour of an individual, or group of animals. Such analyses have the potential to quantify behavioural markers of pain and stress and quantify abnormal behaviour objectively. This review seeks to explore the scope of such analytical methods as behavioural indicators of welfare. We outline four classes of analyses that can be used to quantify aspects of behavioural organization. The underlying principles, possible applications and limitations are described for: fractal analysis, temporal methods, social network analysis, and agent-based modelling and simulation. We hope to encourage further application of analyses of behavioural organization by highlighting potential applications in the assessment of animal welfare, and increasing awareness of the scope for the development of new mathematical methods in this area.

Assessment of welfare of suckling lambs following intradermal injection of cetrimide as a non‐surgical alternative to conventional mulesing

To assess in suckling lambs the impact of intradermal injection of cetrimide, a quaternary ammonium compound formulated to induce non-surgical mulesing, on some physiological and behavioural indicators of welfare. We allocated 32 suckling lambs (9-11 weeks old) to three groups: (1) control (n = 10), (2) conventional surgical mules (n = 11) and (3) non-surgical mules (n = 11). Non-surgical mulesing was induced by intradermal injection of 4% (w/w) cetrimide + 3% (w/w) polyvinylpyrrolidone in water. Lambs were run in pens of four together with their dams. Haematology, cortisol, beta-endorphin and haptoglobin levels, and rectal temperature were monitored at least daily for the first 7 days after treatment, then weekly until day 28. Body weight was measured weekly and behaviour was measured every 15 min for 12 h on the day of treatment, then on days 1, 2, 4, 6, 12, 21 and 28 following treatment. The intradermal treatment induced local tissue swelling, systemic signs of severe inflammation, including high fever (> 41.0 degrees C) and elevated blood cortisol levels, by 12 h. Rectal temperatures were significantly elevated until 6 days after treatment, cortisol levels were elevated until 4 days after treatment, haptoglobin levels for at least 7 days after treatment and the neutrophil to lymphocyte ratio until 5 days after treatment. Peak cortisol values were comparable in mulesed lambs and lambs receiving the intradermal treatment, whereas the areas under the curves for cortisol and temperature were greater in lambs receiving the intradermal treatment than in mulesed lambs. Beta-endorphin levels were significantly elevated in mulesed sheep at 12 h. There was no effect of intradermal treatment on average daily gain, fibre diameter or beta-endorphin concentration. Mulesed lambs spent 44% of the time in abnormal behaviours (hunched standing, stiff walking, pawing, lateral lying and lying intention) on the day of treatment. On the day after treatment, lambs receiving the intradermal treatment spent 11% of the time (comparable to mulesed lambs) in abnormal behaviours. In comparison, control lambs spent 0.4% of their time in abnormal behaviours on the same day. The welfare of suckling lambs that were non-surgically mulesed by intradermal injection of cetrimide was measurably poorer than control lambs.

Effect of Access to Roughage and Shelter on Selected Behavioural Indicators of Welfare in Pigs Housed in a Complex Environment

AbstractThe aim of this study was to examine the effects of roughage and shelter on certain welfare indicators in growing pigs that have access to ample straw and space. The effects of the two treatments were evaluated both by recording the pigs’ use of the various areas of the pen and by measuring the frequency of two specific behaviours, ‘aggression’ and ‘play’, that are considered to be significant indicators of welfare in pigs. Seven replicates were used, each involving 96 pigs. The pigs were randomly allocated to eight experimental pens at 10 weeks of age, and were observed from 13 to 22 weeks of age. The two treatments, roughage and shelter, were distributed according to a 2 x 2 design in the pigs’ outdoor runs, four of which were located on each side of the barn (north side versus south side). The pigs spent most of their time in the straw-provided areas, and the frequency of their aggressive behaviour was also the highest in these areas, suggesting that these locations were the most attractive to the pigs. The pigs with access to roughage showed a lower frequency of aggression (P &lt; 0.05) and spent more time in the outdoor area where the roughage was placed than those pigs with no access to roughage (P &lt; 0.05). No other effects of treatment were found on the length of time spent in the different pen locations. Play frequency decreased with age (P &lt; 0.05) and with increasing temperature (P &lt; 0.01). Moreover, when housed on the south side of the building, the pigs with access to shelter played more than those without (2.0 versus 1.0 events per hour [SE = 0.3]; P &lt; 0.05); this suggests that the opportunity to regulate the body temperature by use of shade results in improved welfare. In conclusion, the pigs’ behaviour indicated that their welfare was improved by free access to roughage and shelter.

Growth, response to humans and corticosteroids in male pigs housed individually and subjected to pleasant, unpleasant or minimal handling during rearing

The effect of aversive handling during rearing from 36 to 92 kg liveweight on growth rate, plasma cortisol concentrations and the behavioural and adrenal responses to humans was investigated using a total of 30 Large White × Landrace crossbred male pigs which were housed and handled as individuals. Ten pigs were allocated to each of three treatments which were: (1) pleasant handling for 1 min, three times week −1; (2) unpleasant handling for 1 min, three times week −1; (3) minimal handling. In pleasant handling, the pigs were patted and stroked if they approached the handler, but in unpleasant handling they received a brief shock with a battery-operated stock goad. Pigs in the minimal handling treatment had no exposure to humans except during weekly weighing. After 8 weeks of treatment (142 days of age, 92.0 kg) all pigs were individually assessed for their behavioural response to a human in a standard 3 min test, during which each pig was observed for: (1) time to enter within 0.5 m radius of the human (Area A); (2) time spent in Area A; (3) time to the first interaction with the human; (4) the number of interactions. The next day four pigs from each treatment were fitted with indwelling jugular vein catheters. Commencing at 09:30 h the following day, blood samples were collected from behind black plastic screens using extensions to the catheters every hour until 18:30 h and every 15 min from 17:45 h until 20:15 h. After the 18:30 h sample was collected a human entered each pig's pen for 2 min. The mean of the ten hourly samples was used as an estimate of basal plasma cortisol concentration, and the adrenal response to a human was estimated from the plasma cortisol concentrations measured in the 11 serial (15 min) samples. There was no significant effect of handling treatment on mean growth rate during either the first or second 4 weeks or over the full 8 weeks of handling. Pigs in the pleasant handling treatment entered Area A more quickly ( P<0.05) and interacted with the human more quickly ( P<0.05) than the unpleasantly handled pigs, but the time they spent in Area A was not significantly different. The time taken for the minimally handled pigs to enter Area A and the time they spent in Area A were not significantly different from either the pleasantly or the unpleasantly handled pigs. However, the minimally handled pigs were significantly quicker to interact with the human than were the unpleasantly handled pigs ( P<0.05). The pleasantly and minimally handled pigs interacted significantly more often with the human than did the pigs which were handled unpleasantly ( P<0.05). Regression analysis revealed no significant relationship (highest R<0.2, P>0.3) between any of the variables measured in the behavioural test and growth rate. Mean plasma cortisol concentration in the hourly samples provided no evidence that any of the treatment groups were chronically stressed. There was no significant effect of treatment ( P=0.67), but there was a significant effect of time on cortisol concentration in the hourly samples ( P<0.001), with mean cortisol concentrations declining throughout the day. There was no significant effect of handling treatment ( P=0.27) or time ( P=0.89) on mean cortisol concentrations in the 15 min samples, indicating no effect of treatment on the adrenal response to the presence of a human. The results of this experiment provide further evidence that the response of pigs to a human in a behaviour test is not necessarily related to their growth performance or to the level of stress which the animals experience. The implications of this finding for the use of physiological and behavioural indicators of welfare and stress in pigs are discussed.