Body language is important for communication between individuals. Body language is based on the fact that the thought of performing a known action, alone, will activate the motor neurons used for the action, resulting in a slight contraction of the involved muscles. These contractions are called intention movements and signal what the sender will do within the next second, enabling the recipient to react. This type of communication is important both for animals and for peoples' interaction with animals. For example, for social animals, body language communication during competitive situations may prevent subsequent physical interaction making life in the social group more peaceful. Domestic animals that have frequent contact with people learn to read human body language. Similarly, experienced animal trainers learn to read the body language of their animals. This exchange of information makes it safer and more efficient to work with horses. The subtleties of body language may also influence results of scientific studies. Research on preferences or cognitive abilities in horses often use choice experiments combined with operant conditioning. Recent studies have thus demonstrated that horses prefer larger quantities of food than smaller quantities, that they have prospective memory, and that they can communicate with people using symbols. These results may be true, but because the experimental horses are handled by people right before they make their choice within the experiment, it is not possible to determine whether their choice is their own or whether it has been influenced by the body language of the handlers. To be valid, this kind of experiment must eliminate any possibility of human influence. In conclusion, better awareness of horses' body language as well as our own body language makes work with horses easier, safer, and more efficient. Furthermore, creating an environment in which foals and young horses are properly socialized will prepare them for an adult life in a social group, something that is a prerequisite for acceptable horse welfare.

There is increasing interest in keeping horses in groups, but progress is hampered by a lack of knowledge about which horses can and should be kept together. Therefore, our objective was to investigate the effect of group composition on the occurrence of injuries among horses, the ease of removing horses from groups and horses' reactivity to a fearful stimulus. Using a matched case control design, 61 groups of horses were studied in Denmark, Norway, Finland and Sweden. They were allocated into groups of similar or different age and sex or where membership changed regularly or remained stable. Injuries were recorded before mixing the horses into treatment groups, the day after mixing and four weeks later. Reactivity of horses to a moving novel object and the behaviour of a horse being removed from its group and the reactions of other group members towards this horse and the handler were evaluated. It was hypothesized that a more socially variable group composition has beneficial effects on behaviour, ease of handling and reducing reactivity whereas frequent changes in group composition has negative consequences, resulting in more injuries. We found that differences in treatment effects were mainly related to breed, rather than group composition. Icelandic horses reacted less to the movement of the novel object (P= 0.007) and approached it more afterwards (P = 0.04). They also had fewer new injuries than warmbloods following mixing (P<0.001) and fewer than all other groups 4 weeks later (P<0.01). Most new injuries after mixing were minor and recorded on the horse's head, chest, hind legs and rump. In conclusion, variations in sex and age composition of the group had little effect on injury level, reactivity and ease of handling compared to the general effect of breed. Concerns about the risk of severe injuries associated with keeping horses in groups are probably overestimated. Thus, we propose that horses can be successfully kept in groups of different sex and age composition. (C) 2016 Published by Elsevier B.V.

Keeping horses in groups is widely recommended but limited information is available about how this is implemented in practice. The aim of this survey was to describe how horses are kept in the Nordic countries in relation to sex, age, breed, and equestrian discipline and to assess owners' attitudes toward keeping horses in groups. Horse owners in Denmark, Finland, Norway, and Sweden were approached using a web-based questionnaire, which was translated into 4 languages and distributed online via equestrian forums, organizations, and social media. The number of respondents was 3,229, taking care of 17,248 horses. Only 8% of horses were never kept in groups, 47% were permanently grouped for 24 h/d, and 45% were stabled singly but grouped during turnout. Yearlings were most often permanently kept in groups (75%), mares and geldings more commonly during parts of the day (50 and 51%, respectively), and stallions were often kept alone (38%). Icelandic horses were more likely to be permanently kept in groups (36%) than warmbloods (16%) and ponies (15%). Twice as many competition horses (51%) were never grouped compared with horses used for breeding (20%) or leisure purposes (15%). The majority of respondents (86%) strongly agreed that group housing benefits horse welfare and that it is important for horses to have the company of conspecifics (92%). Nevertheless, not all horses were kept in groups, showing that attitudes toward group housing may not necessarily reflect current management. The risk of injury was a concern of many respondents (45%), as was introducing unfamiliar horses into already established groups (40%) and challenges in relation to feeding in groups (44%). Safety of people (23%) and difficulties handling group-kept horses (19%) were regarded as less problematic. Results suggest that the majority of horses have the possibility to freely interact with other horses, either as fulltime members of a group during 24 h/d or during turnout. Future research should address the extent to which being a part-time member of a group affects horse welfare. For permanent group housing to become more widespread, such as it is the case for most farm animals, future research could focus on solving some of the reoccurring problems perceived with keeping horses in groups. The dissemination of evidence-based information on all aspects around keeping horses in groups can ultimately stimulate further positive changes in the management of group-kept horses.

The aim of this study was to document effects of two high-intensity training regimes on horse health. Sixteen Standardbred horses in training from September as 1-year-olds with the goal to race as 3-year-olds were used in a 2.5 year study. Horses were trained in either a control training program (C-group) or in a program with 30% reduced high intensity distance compared to the C-group (R-group). Clinical examinations were performed nine times. Locomotion asymmetry was registered with a sensor-based system 17 times.There was no difference in health scores, locomotion asymmetry or veterinary treatments between groups. Subjective lameness score and objective front limb locomotion asymmetry increased during the spring both as 2- and 3-year-olds after introduction of speed- and uphill interval training but decreased during winter. Hind limb locomotion asymmetry increased during spring as 2-year-olds and was still above initial level in December as 3-year-olds. Horses that qualified for races early had less asymmetric front limb locomotion and were less lame in clinical examinations (0.7 ± 0.3 vs. 1.6 ± 0.2 degrees [AAEP scale], P = 0.04) than late qualifiers. Days lost to training were higher in C-group than in R-group (27 ± 3% and 17 ± 3%, P = 0.029). It is concluded that (1) less days may be lost to training by reducing the high intensity training distance and (2) the introduction of new training may alter locomotion asymmetry and this can be detected with objective locomotion analysis.

The ability of horses to learn through social observation may ease the implementation of new management systems, because the use of automatic feeders etc. by naive horses could be facilitated by observation of experienced horses. However, previous studies found no documentation for observational learning abilities in horses. This study aimed to investigate the ability of horses to learn an instrumental task from a familiar conspecific when social interaction was allowed during the demonstration. Two similar experiments were performed. In the first experiment, Observer horses (n=11) participated in ten successive demonstrations, where a trained Demonstrator opened an operant device by pushing a sliding lid aside with the muzzle in order to obtain a food reward. Immediately after the demonstrations the Observer horses were given the opportunity to operate the device alone. Control horses (n=11) were aware that the device contained food but were presented to the operant device without demonstration of the task. The learning criterion was at least two openings. Accomplishment of and latency to accomplish the learning criterion, and investigative behaviour towards the operant device were recorded. Five Observers and one Control, out of the eleven horses in each treatment group, accomplished the learning criterion. Even though this presents a high odds ratio (OR) in favour of the Observer treatment (OR=7.6), there was no significant difference between the treatment groups (P=0.15). Analysis of investigative behaviour showed, however, that the demonstrations increased the motivation of the Observer horses to investigate the device. Subsequently, a similar experiment was performed in a practical setting with 44 test horses (mixed age, gender and breed). We used the same operant device and the same number and type of demonstrations, although the horses were held on a loose rope to minimise aggression. In this second experiment, six of 23 Observer horses and five of 21 Control horses learned the instrumental task, representing no influence of the demonstration. Thus, this study did not demonstrate an ability of horses to learn an instrumental task through observation.

The traditional way to train horses is by the application of negative reinforcement (NR). In the past few years, however, the use of positive reinforcement (PR) has become more common. To evaluate the effectiveness and the possible stressor effect of the 2 training methods, 12 horses showing severe trailer-loading problems were selected and exposed to trailer-loading. They were randomly assigned to one of the 2 methods. NR consisted of various degrees of pressure (lead rope pulling, whip tapping). Pressure was removed as soon as the horse complied. PR horses were exposed to clicker training and taught to follow a target into the trailer. Heart rate (HR) was recorded every 5 seconds and behavior denoting discomfort was observed using one-zero sampling with 10 seconds sampling intervals. Training was completed when the horse could enter the trailer upon a signal, or was terminated after a maximum of 15 sessions. Of the 12 horses, 10 reached the criterion within the 15 sessions. One horse was eliminated from the study because of illness and 1 PR horse failed to enter the trailer. A Mann–Whitney U-test indicated that the horses trained with NR displayed significantly more discomfort behavior per training session than horses trained with PR (NR: 13.26 ± 3.25; PR: 3.17 ± 8.93, P < 0.0001) and that horses in the PR group spent less time (second) per session to complete the training criterion (NR: 672.9 ± 247.12; PR: 539.81 ± 166.37, P < 0.01). A Mann–Whitney U-test showed that no difference existed in mean HR (bpm) between the 2 groups (NR: 53.06 ± 11.73 bpm; PR: 55.54 ± 6.7 bpm, P > 0.05), but a Wilcoxon test showed a difference in the PR group between the baseline of HR and mean HR obtained during training sessions (baseline PR: 43 ± 8.83 bpm; PR: 55.54 ± 6.7 bpm, P < 0.05). In conclusion, the PR group provided the fastest training solution and expressed less stress response. Thus, the PR procedure could provide a preferable training solution when training horses in potentially stressing situations.

For many veterinarians, animal welfare is a matter of animal health: As long as an animal is healthy, it is also happy. For the past forty years, however, behaviour biologists have shown repeatedly that, whereas poor health contributes to poor welfare, the opposite is not necessarily the case. There is more to good welfare than good health. Numerous studies have shown that, despite many generations of selection for various traits, the behavioural repertoire of domestic animals is almost identical to that of their wild ancestors. A broiler chicken has a similar demand for dust bathing as a jungle fowl. A thoroughbred racehorse has the same demand for social contact as the Przwalski horse. These are just two of many other examples. Consequently, to ensure a certain level of welfare in our domestic animals, it is important that they are able to perform their species-specific behaviour beyond eating behaviour, drinking behaviour, eliminative behaviour and resting behaviour. And that's where the controversy begins! Which elements of the animal's ethogram are essential and which ones are not? Must a prey animal show flight behaviour regularly to be happy? Must a well-fed animal show foraging behaviour to be content? Is social contact through bars enough contact? The controversy consists of, on the one side, practitioners or producers that need to house and manage animals in such a way that their production is productive and, on the other side, animal protection people or animal rights people who are against any exploitation of the domestic animals. As with most issues, obviously the optimum lies somewhere in between these two extremes. We all have to compromise and so must our domestic animals. In return for regular food, water, shelter and medical care, the animals must give up some of their freedom. But how much they must give up, how restrictively we can keep them with good conscience, is a matter of dispute. The veterinary profession plays a key role in the controversy in that it possesses a detailed knowledge of both camps. Practicing veterinarians and veterinary inspectors are in regular contact with the animals, either in the clinic or during visits to the farms, either to treat sick animals, to institute preventive measures, or to control that legislation is being followed. At the same time veterinarians possess (or should possess) the scientific background that enable them to judge the welfare of their patients and clients. Public concern for the welfare of domestic animals is likely to increase in the future. At the present time behaviour biologists still struggle with the difficult task of measuring happiness in the animals. Similarly, programs for monitoring welfare in praxis are being developed in many countries. An important question in these developments is how the veterinary profession can best prepare itself for future challenges, both in the veterinary curriculum and in terms of continued education.

1. The effects of light source and intensity on leg health and performance of female ROSS 308 broiler chickens were investigated in a 2 x 2 experimental design (8 groups of 275 chicks) of two light sources (Osram biolux and Osram warm-white) and two light intensities (5 and 100 clux, adjusted to fowl-perceived illuminance).2. At 41 d of age, body weight, gait-score, footpad dermatitis and hock-burn were measured on 50 birds from each light environment. In addition, weekly feed intake and body weight were determined on a group basis and mortality was recorded continuously.3. The light environment did not affect the severity of the gait-score or hock-burns. The risk of moderate to severe lameness and hock-burns increased with body weight. Birds weighing more than 2400 g had an increased probability of moderate footpad lesions in biolux light.4. Weight and gait-score, as well as gait-score and hock-burn were positively correlated. Podo-dermatitis was weakly correlated with hock-burn, which contradicts earlier findings. The light environment did not affect feed intake, body weight or mortality.5. The light sources and intensities employed in this study did not adversely affect production or leg health of broiler chickens reared semi-commercially.

Just as health is characterized primarily by the absence of disease, welfare can be characterized partly by the absence of abnormal behaviour or behaviour problems. Consequently, just as treatment and prevention of disease improves health, treatment and prevention of behaviour problems can improve welfare. The purpose of developing a discipline termed 'clinical ethology' is to apply the same procedures and principles used in medicine to the area of ethology. Briefly, these procedures consist of searching for specific symptoms of a disease, partly through a clinical examination and partly by conducting specific diagnostic tests, the results of which point to a specific diagnosis. Based on the diagnosis, suggestions for treatment as well as preventive measures are given.Application of clinical procedures to the treatment and prevention of behaviour problems reveals some areas that need improvement. One such area concerns the diagnostic process, i.e. the search for specific symptoms of the various problems through behaviour observations and behaviour tests. Another area concerns the treatment of behaviour problems, something that primarily is done in companion animals and in horses and less so in farm animals. A third area concerns the prevention of behaviour problems, an area that despite much attention still needs refinement, before exact recommendations can be given to the client.As many behaviour problems are related to the way people house and handle domestic animals, possibly the most important aspect of clinical ethology is its focus on the human-animal interaction, to subject this interaction to systematic investigation, and to include it both in the diagnostic, the therapeutic, and the preventive part of the clinical process.Developing a discipline of 'clinical ethology' could (I) improve the welfare of domestic animals in a way that is perceived by animal owners as a professional help based on scientific knowledge and (II) stimulate ongoing research by emphasizing the therapeutic and preventive aspects of solving behaviour problems in farm and companion animals. In addition, such a development could (111) create new jobs for 'behaviour practitioners'. (c) 2005 Elsevier B.V. All rights reserved.

Effects of acute stressors on behavioral, adrenocortical and nociceptive responses were examined in 24 dairy cows kept in tie stalls, using 15 min of social isolation in novel surroundings (ISOL), fixation by the head in the home stall (FIX) and the provision of novel neighbors/stall (NEIGH) as acute stressors as well as a control treatment (CON). Each cow was exposed to one treatment daily in a balanced order. All stressors led to signs of hypoalgesia as indicated by slower (P=0.01) and reduced responses (P<0.10) toward nociceptive laser stimulation after exposure to the acute stressors. ISOL, however, had stronger effects than FIX or NEIGH. ISOL or FIX led to increased plasma concentration of cortisol (P<0.001), whereas NEIGH or CON did not. The behavioral responses were affected by treatments as well, as shown by decreased rumination for all stressors (P<0.001) and a gradual increase in active avoidance from CON to NEIGH to FIX (P<0.001). Furthermore, exposure to NEIGH led to increased exploration (P<0.001), aggression (P<0.10) and self-grooming behavior (P<0.10) compared with the CON treatment. The results suggest that nociceptive changes are part of responses toward acute stress in dairy cows. The nociceptive changes, however, were not direct reflections of the adrenocortical or behavioral responses toward the acute stressors. Therefore, quantification of nociceptive changes, in combination with behavioral and physiological registrations, can be one way to broaden the range of biological systems, considered for the study of animals under stress, and thereby extend the understanding of responses toward acute stress in dairy cows.

The use of demand functions to identify the behaviours most important to animals has been advocated widely. The principle is to place increasing cost on the opportunity to perform several behaviours and subsequently to rank these behaviours according to the change in their performance as a function of cost, this change is described by the elasticity of the demand function. However, the method has been criticised for placing the animal in too artificial a setting. Firstly, the animal works repeatedly for short periods of access to a resource, which may interrupt bouts of behaviour, secondly, animals are tested in isolation, which may affect their motivation to perform the target behaviour, and, finally, assumptions regarding the effect of prior deprivation and reward duration on elasticity of demand need to be tested This criticism, however, is important only if these factors do affect the elasticity of the resulting demand function. This paper reviews experiments that have developed methods to assess the importance of various behaviours to farm animals and that have tested the effect of social context length of deprivation of a resource and reward duration. It is concluded that the elasticity of demand function may be used to assess the relative importance of various behaviours, but that it is important to make sure that the experimental set-up yields valid estimates of the elasticity of demand.

To determine if bedding has any influence on the time horses spend recumbent, 8 horses kept on straw and 8 kept on wood shavings were observed from 10:00 PM to 5:30 AM for two successive nights. Observations were conducted using time-lapse video recordings. Lying down and rising behavior, as well as frequency and duration of bouts spent in lateral and sternal recumbency, was registered. The results showed that horses on straw were lying in lateral recumbency three times longer than horses on shavings (P < .001), whereas the time horses spent in sternal recumbency did not differ. The longest period of noninterrupted lateral recumbency was longer for horses on straw than for those on shavings. Because horses must lie down, preferably in lateral recumbency, to achieve paradoxical sleep, the reduced time spent in lateral recumbency in horses on wood shavings may affect their welfare and performance. Independent of the bedding, we further observed that, as the horses got up from recumbency, most of them made attempts to roll over before rising. This behavior appeared to be caused by some difficulty in rising, possibly due to the box size, and might have a connection with the fact that horses sometimes get stuck against the box wall.

In an experiment on the effects of social environment and training on the human–animal relationship, 20 horses were handled according to a defined schedule. Eight horses were housed singly and 12 horses were housed in four groups of 3 horses. Horses were handled three times per week in 10min sessions from an age of 6 months until 2 years of age during two winter periods. A total of 50 and 70 sessions were given in the first and second period, respectively. Five randomly allocated people performed the training. The training scheme involved leading, tying up, touching, lifting feet, etc. in 43 stages. The horse had to fulfil the performance criteria of each stage in order to get to the next stage. In the first winter period, horses were led to the stable when they had “passed” a stage or after 10min of training. In the second winter period, horses would start off at stage 1 again, and when they “passed” a stage they went on to the next stage within the same training session. Because of the change in training procedure results were analysed separately for the two winter periods. There was a significant difference between trainers in the number of times they allowed a horse to “pass” a stage within each winter period (χ32, P<0.05; χ32, P<0.001 for the first and the second winter period, respectively). Group housed horses “passed” more stages than single housed horses (17 versus 14; 27 versus 18 in the first and second winter period, respectively; P<0.05 for the interaction). Singly housed horses bit the trainer more frequently than did group housed horses (P<0.01). The responses of group housed horses to training clearly demonstrate the benefits of raising young horses in groups.

Demand functions were used in an attempt to estimate the importance of resting in cattle. Furthermore, the sensitivity of the technique was determined by quantifying the effects of variations in the level of prior deprivation (Experiment 1) and reward duration (Experiment 2) on elasticity and intensity of the demand function. In both experiments eight heifers were housed in tether stalls where they could be deprived of lying by attaching a girth strap secured to a rafter above the animal. During a 3-h test period (10:00 to 13:00h) a panel was placed in front of each heifer and she could work by pressing this panel on Fixed Ratio (FR) schedules for a releasing mechanism to be activated allowing her to lie down (a reward). In Experiment 1 the heifers were deprived of lying twice daily (afternoon and morning) for either two periods of 3h (2×3h) or two periods of 6h (2×6h) prior to testing. The FR varied from 6 to 24 and the reward duration was 15min. In Experiment 2, heifers could lie for either 10 or 20min per reward at either of the two deprivation levels used in Experiment 1. Thus, the four treatments were (A) 2×3h of deprivation and 10min per reward, (B) 2×6h of deprivation and 10min of reward, (C) 2×6h of deprivation and 20min of reward, and (D) 2×3h of deprivation and 20min of reward. Here the FR varied from 10 to 50. The demand functions were linear in arithmetic co-ordinates, which means that the elasticity may not be constant across FR-values. In Experiment 1 the heifers earned more rewards the higher deprivation level (P<0.001). The elasticity of demand was calculated for each FR-value for the two levels of prior deprivation. For 2×3h of deprivation the numerical elasticity increased from 0.07 to 0.35 with increasing FR (P<0.001). For 2×6h of deprivation the numerical elasticity tended to increase (P<0.10) from 0.02 to 0.10. The demand was more inelastic after the longest prior deprivation for the highest FR-values (P<0.05), which indicates that the heifers valued access to rest more after the longest deprivation. In Experiment 2 the heifers earned more rewards after two periods of six hours of deprivation when a reward duration of 10min was given than when a reward duration of 20min was given (P<0.01). The numerical elasticity of the demand functions increased with increasing FR from 0.07 to 0.5 (P<0.001), from 0.06 to 0.4 (P<0.001), from 0.03 to 0.2 (P<0.05) and from 0.04 to 0.3 (P<0.05), for treatments A, B, C and D, respectively. After the longest deprivation the demand function was less elastic when a reward duration period of 20min was given compared to a reward duration of 10min (P<0.05). These results indicate that the longest reward duration was more valuable than the shortest when the deprivation prior to test was high. The variation in elasticity with prior deprivation and reward duration has to be considered in future studies of the demand for rest in dairy cattle.

We developed a method to assess the substitutability of two reinforcers by using the divergence of the cross point of two demand functions. Two kinds of water were used as reinforcers, namely distilled water and quinine water. We tested 16 rats, Rattus norvegicus, from two strains in a closed economy. A single demand function for each kind of water was established. Then, two reinforcers were presented on concurrent fixed-ratio schedules. Finally, a control condition with distilled water for both responses was run. Demand functions were generated on scales with fixed-ratio values on the X axis and number of reinforcers obtained on the Y axis. The cross point of the functions differed significantly between the two strains of rats in both conditions within each condition. Furthermore, there was a significant difference within strains between the conditions. On evaluating the single demand functions, we found a significant difference between the slopes of the two demand functions, but no strain differences in demand. In addition, the results revealed a disagreement between demand assessed by using the slope of the single demand function and the results using the double demand function, with the results of the double demand function being in accordance with simple choice behaviour of the rats in their home environment. Using the cross point of two demand functions provides a measure of substitutability and, furthermore, the method appears to be a more sensitive measure of animal priorities than single demand functions. (C) 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

The degree of stress was estimated in two individual housing conditions (large pens with straw bedding, small metabolic cages with slatted floor without straw) and in two malignant hyperthermia syndrome (MHS) genotypes (NN and Nn) by means of plasma cortisol concentration. MHS genotype was determined by a DNA-based test. three replications were done, each including eight German Landrace barrows, four (2 NN, 2 Nn) housed in pens and four (2 NN 2 Nn) in metabolic cages (24 animals in total). Blood samples of all animals were collected simultaneously every 15 minutes between 8.00 and 11.00 a.m. on days 8, 22 and 36 after the insertion of intravenous catheters. The animals in metabolic cages had higher plasma cortisol values than the animals in pens, which indicates that extreme confinement is a severe stressor. NN animals had higher plasma cortisol values than Nn animals. This indicates a relationship between MHS and the adrenal function.

To validate a laser-based method to measure thermal nociception in dairy cows (e.g., for the use in studies on stress-induced analgesia), we performed three experiments to observe the behavioral responses to a computer-controlled CO2 laser beam applied to the skin on the caudal aspect of the metatarsus. In Exp. 1, effects of power output (0, 1.3, 1.8, 2.2, 2.4 and 2.6 W) on nociceptive responses were examined using 18 dairy cows kept and tested in tie stalls. Increasing the power output affected the latencies to respond (decreasing latencies, P < or = 0.01), types of response (less nonresponding and more kicking, P < 0.0001), and behavior during (increasing frequency of tail flicking, P = 0.003) and between single laser exposures (increasing frequency of kicking, P = 0.02). Therefore, behavioral responses to a laser stimulus seem to be a valid measure of nociception in dairy cows. Repeatability within 15 min was investigated in Exp. 2 using n = 36 dairy cows kept and tested in tie stalls and a power output of 1.8 W. The variables' latency to move the exposed leg and frequency of tail flicking during laser exposure showed the highest level of repeatability (0.50 and 0.38, respectively). However, retesting at t = 15 min led to increased responses in terms of shorter latencies to respond (P < 0.05), increased kicking (P = 0.05), and tail flicking (P = 0.02), which probably can be explained by sensitization. Effects of power output (1.0 vs. 1.8 W) and skin condition (naked vs. intact) were examined in Exp. 3 on 11 group-housed dairy cows, tested just outside their home pen. Increasing the power output and shaving off hair led to increased responses as seen by shorter latencies to respond (P < 0.0001), less nonresponding (P < 0.0001), and increased kicking (P = 0.0003), as well as reduced intra- and interindividual variability (P < or = 0.04). In conclusion, the results of these experiments suggest that behavioral responses to laser stimulation are a valid and reliable measure of nociception in dairy cows, especially when applied on naked skin, both in the home environment and just outside a group pen. The fact that repeated testing in itself at t = 15 min led to increased responses means that the test will be a conservative measure of stress-induced analgesia.

Demand functions generated by operant conditioning techniques are used to measure animals’ motivation to obtain a certain reinforcer. Since specific reinforcers allow the animals to perform specific behaviours, the method can be used to compare and rank different behaviours according to their importance to the animals. One question in this type of research, however, is whether the measured value of an activity is influenced by the opportunity to perform the behaviour outside the test session (so-called open economy), in comparison with the situation where the activity is restricted to test sessions only (in a so-called closed economy). To test the effect of closed versus open economies on the slopes of demand functions, and offering the commodity used as reinforcer for various durations or at various times before or after the test, rats were required to work for drinking water on increasing fixed ratios (10, 30, 50, 70, and 100 lever presses per reinforcement). In condition 1 they were not given water outside the daily test. In conditions 2 and 3, they were given water for 10 and 30min, respectively, immediately after the test. In conditions 4–6, they were given additional water for 10min 2h after the test, 4h before the test, and 1h before the test, respectively. The slopes for the closed economy condition 1 was the shallowest at −0.35. Provision of 10min of water immediately after or 2h after the test sessions, or 4h before the test gave slopes of −0.56, −0.70 and −0.70, respectively. The slopes for the conditions where water was given for 30min immediately after the session and for 10min 1h before the session were −0.81 and −1.09, respectively. All the slopes differed significantly from each other, except for conditions 4 and 5, when water was given for 10min 2h after or 4h before the test. We conclude that testing rats in an open economic system by giving them additional water outside the test resulted in steeper slopes. Water given 1h before the test sessions increased slopes in the open economy the most, and provision of a greater quantity of water immediately following the test had a larger effect on slopes than a more limited provision. Availability of a commodity used as a reinforcer outside the test situation can thus affect the demand significantly and must be taken into consideration when demand functions are used to measure animals’ motivation.