Piglet mortality is a major welfare and economic problem in the pig industry. Despite the use of farrowing crates, piglet crushing remains a major contributor to pre-weaning piglet mortality, which is typically around 12%. Our aims in this study were to quantify variability between sows and consistency across parities in crushing mortality, and to examine the effect of the environment on variability. In our first study, we compared the variability in crushing mortality in 122 primiparous sows (gilts) that farrowed in crates (71) or open pens (51). Certain sows crushed more or fewer piglets than expected by chance. Crushing was more frequent and more variable in pens compared to crates, indicating that crates may mask differences between sows. In our second study, we recorded piglet mortality for 125 sows, which farrowed in crates over several (4–9) parities. After adjusting for litter size, litter weight and parity effects, consistent individual differences between sows were evident. The repeatability of crushing was estimated at 0.14, with estimates of 0.18 and 0.05 for stillborns and total liveborn mortality, respectively. Although these repeatabilities are relatively low, there was a high degree of phenotypic variance (eg sows crushed between 0 and 30.8% of their piglets). Given that sows show some consistency in piglet mortality over parities, this could be used to inform culling decisions. Additionally, if differences in piglet crushing between sows have a genetic component, a breeding programme might reduce mortality from crushing. Because crates restrict maternal behaviour, genetic selection in this system may have relaxed selection for good maternal behaviour. Selection for reduced piglet mortality, and thus improved maternal abilities, could remove a major obstacle to the wider adoption of less restrictive farrowing systems, with positive welfare consequences for the sow and piglets.

Management systems allowing free nest access are widely used in commercial rabbit breeding, but these produce a potential conflict with the doe's behavioural goal of a closed nest entrance. Furthermore, the restricted space in commercial breeding units prevents the doe from achieving a sufficient distance between her and the nest, another highly adaptive behavioural goal. This can lead to behavioural problems and pup mortality higher than 20%, attributable to hypothermia, injuries, weakness caused by the scattering and crushing of pups, or even cannibalism. In this study we tested a type of nest entrance (a metal cat-flap) that visually closed the nest box while still allowing the doe free access during the first 15 days after parturition. The effects of a cat-flap access (group CF) and of a permanently open nest box (group O) on nest-related behaviour, general activity, and plasma corticosterone concentration of the does, and on the mortality and weight of the pups, were compared using 15 ZIKA does in each group. Over 24 h, there was no difference between the groups in the frequency of ‘nest controls’ (approaches or entries to the nest without nursing of pups). However, outside nursing hours, does in group O showed more ‘head contacts’ with the nest, whereas does in group CF performed more nose contacts and nesting activities outside the nest. Does in group O performed twice as many potentially disturbing nest contacts in this time than does in group CF and had a higher increase of corticosterone after the administration of exogenous adrenocorticotrophic hormone. Pup mortality from days 16 to 35 was significantly higher in group O, and pups born to does in group O left the nest earlier. There was no significant difference in the weaning weights of pups between the two groups. As does with a cat-flap at the nest entrance still showed repeated nest approaches, the cat-flap possibly did not block all nest stimuli from the does. Alternatively, it is possible that the repeated approaches to the next box result from its being one of very few attractive or interesting features in an otherwise barren environment. Removal of the nest box from the cage is an effective method to eliminate nest stimuli, but this increases work for the staff without improving the barren environment for the rabbits. A better way of increasing the distance between the doe and the nest, as well as presenting a number of other attractive features, is group-housing of does.

At present, animal experimentation remains central to our understanding of human disease-related processes and of the biological effects of many substances. Traditional experiments have relied heavily on invasive techniques to monitor changes in blood biochemistry, tissue structure or function, or to phenotype or genotype genetically modified animals. In some cases, a proportion or all of the animals used during the course of a study may be sacrificed for histopathological assessment. In most cases, this is to track the progression or regression of a disease over time, or to determine the levels of toxicity evident in specific organs or tissues. However, many of these techniques fail to provide details of how a disease develops or how a substance elicits its effects. In recent years there has been a gradual increase in the application of imaging techniques that were originally developed and used in fundamental research or in medicine. These non-invasive techniques allow diseases, and responses to exogenous substances, to be monitored in a temporal and spatial manner, therefore allowing a greater amount of information to be derived from smaller numbers of animals, which in turn, increases the statistical validity of the data by reducing the level of experimental variation. Non-invasive imaging also allows more informative and humane endpoints to be used and, perhaps most importantly, allows functional details to be studied in the context of a living animal. Some of the recent developments within the field of non-invasive imaging and their significance with respect to animal welfare and the understanding of human physiology are discussed.

Gavaging (oral dosing) has previously been shown to have only a short-term effect on behavioural parameters in the laboratory rat. The aim of this study was to determine if the gavaging of laboratory rats influenced their heart rate, blood pressure and body temperature, and if so, whether the duration of this impact correlated with the volume gavaged. The three stress parameters were measured using telemetric transponders placed in the abdomen of eight female Sprague-Dawley (Mol:SPRD) rats. Using a Latin Square cross-over design, the rats were gavaged with three different doses of barium sulphate (4, 10 and 40 ml kg–1); in addition, there was a control of no dose, only insertion of the tube. The heart rate, blood pressure and body temperature of the rats were monitored continuously for 4 h after dosing and again for 1 h, 24 h after dosing. The gavaging of laboratory rats was shown to induce an acute reaction: after 30 min, blood pressure and heart rate were significantly higher than before gavaging, and body temperature was significantly higher 60 min after gavaging — indicators of stress levels comparable to those of other basic experimental procedures. A significant correlation between heart rate and dosage was observed until 10 min after gavaging. This indicates that the dosage gavaged is of only minor importance in causing stress, and only important for the most acute reaction. However, because of the resistance and discomfort observed when administering a 40 ml kg–1 dose, this dose should be administered only with caution.

Nowadays, zoos are increasingly concerned with animal welfare as public expectations and knowledge of the needs of captive animals increases. Although many zoos try to provide all sorts of enrichment for their big cats, the importance of social enrichment is not yet fully understood. This study investigates the effect of different social housing conditions on the behaviour exhibited by captive tigers (Panthera tigris). It was found that paired tigers performed a wider variety of behaviours than single tigers (mostly direct social interactions). Single animals spent significantly more time rolling, auto-playing and performing flehmen. Moreover, paired tigers without neighbouring tigers exhibited significantly less pacing than those with neighbouring tigers. These results suggest that housing tigers in pairs is preferable for the animals as they are able to perform a wider range of natural behaviours, and that the presence of neighbouring tigers causes stress and frustration, and hence more pacing.

This study explored the influence of five types of visual stimulation on the behaviour of 50 dogs housed in a rescue shelter. These conditions were: one control condition (no visual stimulation) and four experimental conditions (blank television screen, and moving televised images of conspecifics, interspecifics [ie unfamiliar animal species] and humans). The dogs were exposed to each condition for 4 h per day for five days, with an intervening period of two days between conditions. The dogs' behaviour was recorded on days 1, 3 and 5 during each condition. Dogs spent relatively little of the total observation time looking at the television monitors (10.8%). They spent significantly more of their time looking at the moving images of conspecifics, interspecifics and humans than at the blank screen, although their interest in all experimental conditions declined over time. Dogs spent more time at the front of their enclosures during all of the experimental conditions than during the control condition. Images of conspecifics were more likely to attract the dogs to the front of their kennels than the blank screen. The conspecific and human conditions of visual stimulation attracted slightly more attention from the dogs than the interspecific condition, although not significantly. All of the experimental conditions encouraged significantly less vocalisation and movement than the control condition. Overall, the findings suggest that the behaviour of kennelled dogs is influenced by visual stimulation in the form of television programmes. Such animals, however, may not benefit from this type of enrichment to the same degree as species with more well-developed visual systems. The addition of other types of enrichment strategy for dogs housed in rescue shelters is advocated.

The opportunity to perform play behaviour may be an important ontogenic activity that stimulates behavioural variability and may enhance an individual's coping capacity later in life. Play behaviour in juveniles may be enhanced by the presence of cage enrichments relevant to the animal's motivations and natural behavioural repertoire. The present study aimed to investigate play behaviour in juvenile farmed mink reared and housed with the cage enrichments standard for the Dutch housing system (ie a cylinder and platform) and in an experimental group of animals with the same standard enrichments but with additional access to swimming water. Juvenile mink with access to swimming water played significantly more in the main cage than mink reared and housed with the cylinder and platform but without swimming water. The results suggest that swimming water presents the animals with biologically relevant stimuli that directly or indirectly influence the development of play behaviour. Specific implications for the animals' long-term welfare are discussed. Future studies should elucidate the effects of juvenile play on the occurrence of abnormal behavioural patterns in adulthood more precisely and more thoroughly.

Growing public concern regarding animal welfare and consumer demand for humanely produced products have placed pressure on the meat, wool and dairy industries to improve and confirm the welfare status of their animals. This has increased the need for reliable methods of assessing animal welfare during commercial farm practices. The measurement of the stress caused by commercial farm practices is a major component of animal welfare assessment. However, a major issue for animal welfare science is that many of the techniques used to measure stress involve invasive procedures, such as blood sampling, which may themselves cause a stress response and therefore affect the measurement of interest. To reduce this problem, a number of non-invasive or minimally invasive methods and devices have been developed to measure stress. These include the measurement of cortisol concentrations in saliva and faeces, and remote devices for recording body temperature, heart rate and the collection of blood samples. This review describes the benefits and limitations of some of these methods for measuring stress. In particular, the review focuses on recent advances and current research in the use of infrared thermography (IRT) for measuring stress. Specific applications for IRT in the dairy and beef industries are also described including an automated, non-invasive system for early diagnosis of infection in cattle. It is essential that non-invasive measures of acute and chronic stress are developed for reliable assessment of animal welfare during standard farm management practices and IRT may be a useful tool for this purpose. IRT may offer advantages over many other non-invasive systems as it appears to be capable of measuring different components of the stress axis, including acute sympathetic and hypothalamic-pituitary-adrenocortical responses.

The welfare of farm animals is a policy area that has increased greatly in importance in recent years. When deciding whether a proposed policy should be implemented, it can be useful for policymakers to compare the costs of the proposed improvement with the perceived benefits. The costs are relatively straightforward to calculate but little is known about the benefits. The Contingent Valuation Method (CVM), a direct survey-based method, can be used to shed some light on this. This approach elicits the willingness-to-pay (WTP) for the provision of some public good or service. This paper reports the results of a contingent valuation study of the value of welfare improvements for growing pigs. Attitudes and opinions with regard to farm animal welfare are explored and WTP elicited for various pig welfare improvements including increases in space allowance, environmental enrichment and research into improved pig housing design. The results reveal a positive WTP for these improvements. However, it is also noteworthy that a significant proportion of the general public is willing to pay nothing for these improvements. Overall, the study illustrates the usefulness of the CVM approach as a tool for policymakers in assessing the merits of possible policy initiatives affecting the welfare of animals.

The use of genetically modified (GM) animals in biomedical research has increased during recent years and its ethical aspects have been subject to ongoing academic discussion. In order to reinforce this discussion, we analysed applications submitted to animal ethics committees in Sweden during 2002. The aim was to investigate the researchers' statements concerning the production and use of GM animals, as well as the committees' assessments of the applications. For our analysis, we constructed an analytic form. In part, we included the questions and categories of the mandatory application form, noting for example species, degree of severity regarding pain and distress, the management of pain, and endpoints. In addition, we included our own specific questions and categories, and classified the applications accordingly. In particular we focused on the methods of GM animal production and on the expected clinical symptoms attributable to genetic modification and experimental use. Our analysis, which was partly quantitative and partly qualitative, revealed that applications were often approved by the committees despite containing insufficient information regarding ethically relevant aspects, that the arguments for using GM animals were often unclear, and that some applicants indicated awareness of possible unintentional welfare effects attributable to genetic modification. In more than 36% of the applications, obvious or minor clinical symptoms attibutable to genetic modification were expected. However, we also noted that many applicants emphasised that certain GM animals were to be used without the expectation that the animals would display any clinical symptoms. This was obviously viewed as an ethical advantage.

Russell and Burch's Three Rs principle of replacement, reduction and refinement offers a useful concept for the scientific and ethical evaluation of the use of animals in scientific procedures. Replacement, reduction and refinement are often considered separately, but when applied, one of the Three Rs may have a positive or negative effect on one or both of the other Rs. This paper explores the interplay between the Three Rs and provides examples where the Three Rs have a positive interaction and where they are in conflict with each other. For example, all Three Rs positively interact in the use of cell cultures, but validation studies of replacement techniques may initially increase the numbers of animals used; therefore replacement and reduction are in conflict. Several models of cost-benefit analyses, used by animal ethics committees to justify or reject animal experimentation, contain elements such as quality and significance of the research, the credibility of the research group and the discomfort caused to the animals. Although these models consider the Three Rs, each R is considered independently of the others. Consequently, moral dilemmas may arise when reviewing proposals in which the Three Rs conflict. Currently there is no legal guidance relating to the prioritisation of the Three Rs, but guidance is required to facilitate their use. For example, does a significant reduction in animal numbers justify increased individual suffering? Moral justifications deserve more attention when considering the Three Rs in general, and when considering the application of one or more Rs to a procedure, to a protocol, or to the wider research programme.

Three inbred strains of male laboratory rat (BN/HsdCpb, BDIX/Or1Ico and LEW/Mol) were provided with nest boxes and nest materials, and were observed for nest-building activity. After 7 days, each cage and nest box was examined. Each nest was weighed and scored for complexity, and returned to the cage. This was repeated after a further 7 days and the nest removed completely. This routine was repeated three times. All three strains of rat built nests inside the nest box and showed the same stages of construction. There was a significant increase in nest complexity between day 7 and day 14 in the strains BN and BDIX. Furthermore, BDIX rats used significantly more material for the nests, compared with the BN and LEW rats. In a second experiment, using the same rats, nest material was offered in four different ways. LEW rats used nesting material irrespective of where it was placed; BN rats only used straw placed on the top of the cage when no alternative was provided in the cage, and would not use the nest box roof when it was covered with bedding; whereas BDIX rats would only use nest material placed within the cage and would not use straw placed on the cage lid. BN rats also used nest material to cover the entrance to the nest box, a practice not carried out by the other strains. This study demonstrates that these rat strains have retained their natural nest-building behaviour. We suggest that the correct stimuli must be provided in order for this behaviour to be exhibited; in addition, the way in which the nest materials are provided must be in accordance with strain-specific characteristics.

Housing conditions can alter both the physiology and behaviour of laboratory animals. Forced-air-ventilated micro-isolation systems increase the efficient use of space, decrease the incidence of disease among laboratory rodents, and provide better working conditions for animal care staff; however, such systems can increase breeding variability and mortality. We examined the possibility that stressors associated with automated housing conditions evoke subtle changes among immune, endocrine, and behavioural parameters in mice housed in a static versus a forced-air-ventilated micro-isolation system. In addition, we assessed the effects of housing in the forced-air-ventilated micro-isolation system both with and without the use of an automatic watering system. Housing in the forced-air-ventilated micro-isolation system, using the automatic watering system, suppressed delayed-type hypersensitivity (DTH) responses, a measure of cell mediated immune function, compared with the responses of mice housed in static cages. Hypothalamic–pituitary–adrenal axis function was also altered by housing in the forced-air-ventilated micro-isolation system with the use of the automatic watering system, such that mice in this housing system had lower resting corticosterone concentrations and increased reactivity to restraint. Despite these changes in corticosterone, housing condition did not alter activity level or exploratory, anxiety-like, or depressive-like behaviours. These results suggest that investigators should carefully consider housing conditions in studies of immune and endocrine function.

Techniques to reduce or prevent behavioural disturbances in singly caged primates vary in form and effectiveness, with some behaviours being exceptionally resistant to treatment. Seven singly caged adolescent male olive hybrid baboons (Papio hamadryas anubis) were selected for behavioural intervention because of their severe abnormal behaviour. A continuous, all-occurrence sampling method yielded mean durations of abnormal and normal behaviour throughout the 10-week study. Analysis of baseline behaviour verified substantial durations of abnormal behaviour (mean = 9.80 min per 30-min observation period). We tested the effectiveness of four enrichment techniques: positive reinforcement training (PRT), food enrichment, non-food enrichment, and social enrichment (pair/trio housing). Each of the four enrichment conditions was implemented for a two-week period, with 10 30-min observations conducted per subject. We used repeated-measures analysis of variance to examine differences in behaviour durations between baseline and each enrichment condition. The social enrichment condition resulted in the most positive behavioural changes, including increased social behaviour and near elimination of abnormal behaviours (mean = 0.69 min per 30-min observation). Significant reductions in total abnormal behaviour levels were also found for other types of enrichment, but only social enrichment and PRT were effective in reducing whole-body stereotypies. Cage-directed and self-directed behaviours significantly decreased, whereas activity levels significantly increased during all enrichment conditions. The results of this project indicate that animate enrichment (human or conspecific stimulation), as opposed to inanimate enrichment, provides optimal means of behaviour modification for singly caged baboons. These findings have substantial implications for the welfare of captive primates in promoting successful therapeutic approaches for the behavioural management of laboratory primate species and for allocating limited enrichment resources.

The ‘coping hypothesis’ of stereotypic behaviour — that stereotypies are performed as a means of helping the animal to cope with its environment by reducing stress — was tested using two adult female margays (Leopardus wiedii), an endangered neotropical small cat species. Within-individual and between-individual comparisons of the duration of stereotypic pacing and glucocorticoid concentration, measured non-invasively in faeces, indicated that stereotypic pacing did not help the two margays to cope with their captive environment by reducing their physiological stress level. However, hiding appeared to serve as a coping function in the two margays, not by immediately reducing the faecal glucocorticoid concentration, but rather as a long-term effect.

Meta-analysis provides a tool to statistically aggregate data from existing randomised controlled animal experiments. The results can then be summarised across a range of conditions and an increased pool of experimental data can be subjected to statistical analysis. New information can be derived, but most frequently the results are a refinement of existing knowledge. By designing experiments and reporting protocols, so that they have the capability of being useful to meta-analyses, maximum benefit can be derived from individual randomised controlled experiments, which may individually have little statistical power, and new avenues for productive research identified. The methodology for meta-analysis is derived from clinical trials in the medical sciences. Now that there is substantial output from animal science experiments, there is an opportunity to apply the technique to these and reduce the need for further experimentation. This paper describes the contribution of meta-analysis to the reduction of animals in research and provides details on data collection, analysis, the models used, and on interpreting and reporting the results. Three applications of meta-analysis to the field of animal science are also briefly described. First, the impact of undernutrition on the production and composition of milk from dairy cows confirmed existing knowledge about partitioning scarce nutrients to milk yield and live weight. Second, increased absorption of cadmium — a widespread toxic element — from organic sources was detected in sheep, which was previously untested. Third, no significant relationships were found between common indicators of undernutrition and weight, and condition score in cattle suggesting that the common indicators used are not suitable as evidence of long term undernutrition. This paper concludes that opportunities exist to increase the information gained from animal experiments by subjecting the results to meta-analysis, particularly if this can be anticipated in advance of study protocols being constructed.

In the past decades the Three Rs concept, famously launched by Russell and Burch in their 1959 book The Principles of Humane Experimental Technique, has gained a prominent place in the landscape of societal and ethical concern about animal use. Important scientific and institutional initiatives have been taken in order to promote replacement, reduction and refinement. It appears, however, that conceptual and ethical thinking about the presuppositions and changing contexts of the Three Rs concept has lagged behind the scientific and practical efforts. In this paper, first, I argue that there is a threefold argument to make for the need to reconsider the moral basis of the Three Rs concept. Second, I outline a number of standard assumptions of the traditional approach to the Three Rs and question the tenability of these assumptions. Third, I propose some elements of a new framework for the Three Rs principle and connect this to a number of developments in science and society. I conclude with four remarks on the future of the ethics of the Three Rs principle.