Attitudes of clients of Dutch pest controllers towards integrated pest management (IPM) and preventive measures in relation to rodent nuisance.

BACKGROUND: Rodent management with lethal methods (e.g., rodenticides) comes with downsides for rodent welfare, the environment and non-target species. To reduce chemical use and prevent rodent nuisance, pest controllers in the Netherlands must work according to the principles of integrated pest management (IPM). A condition for the success of IPM is that there is sufficient engagement of all parties involved, including clients of pest controllers. The aim of this study was to gain insight into the attitudes of clients regarding rodent control, IPM and the application of preventive measures. Insight into their attitudes may contribute to a better implementation of IPM and with that to a more sustainable rodent management based on more effective prevention. An online survey among 248 clients of Dutch pest controllers from both the agricultural and other sectors was carried out. RESULTS: Respondents from the agricultural sector had a relatively negative attitude towards IPM, the new IPM regulations in the Netherlands and had little confidence in prevention. In other sectors, respondents were more positive about IPM and had more confidence in prevention. The respondents from the latter subgroup had a similar attitude compared to Dutch pest controllers who participated in a previous survey. CONCLUSION: The findings of the study provide information for the further development and practical implementation of IPM and preventive measures and with that a more sustainable and animal friendly rodent management. They can also be helpful for a better communication and cooperation between pest controllers and their clients. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Adaptation of Maslow's Hierarchy of Needs to the Hierarchy of Dogs' Needs Using a Consensus Building Approach.

It is crucial for good dog welfare that humans be able to accurately and adequately recognize and meet dogs' needs. However, humans may do a poor job of recognizing dogs' needs due to their tendency to anthropomorphize. The aim of this study was to develop a framework for dogs' needs that would help humans to recognize and meet their actual needs, thereby improving dogs' quality of life. Using the Delphi method, to reach as close to a consensus as possible from an expert panel, Maslow's Hierarchy of Needs was adapted to become the Dogs' Hierarchy of Needs. To do so, the relevant scientific literature was reviewed to identify 37 specific dog needs, which were group into seven need groups. Those groups were then organized onto five need levels, which were as analogous to Maslow's Hierarchy of Needs as possible. The expert panel was asked to assess various aspects of the adapted hierarchy in comparison to the original, including face validity, whether they agreed with how the need levels were ordered in terms of importance/priority, and whether they felt that any need groups should be more or less prioritized for any specific dog categories (e.g., senior dogs). After three rounds of expert feedback, there was sufficient consensus for all aspects except items pertaining to the prioritization of any need groups for specific dog categories. That aspect of the adapted hierarchy will need to be readdressed in the next phase of this project: the development of a tool to assess the quality of life of dogs that reside in shelters/rescue organizations and post-adoption once they have been rehomed.

Sensor-supported measurement of adaptability of dogs (Canis familiaris) to a shelter environment: Nocturnal activity and behavior.

Every shelter dog is faced with the challenge to adapt to a kennel environment. To monitor the welfare of individual shelter dogs, evaluating behavioural and physiological parameters, potentially useful as indicators for adaptability of individual dogs is crucial. Nocturnal activity, i.e. resting patterns, has already been identified as a candidate indicator of adaptability and can be easily measured remotely with the help of sensors. We investigated the usefulness of a 3-axial accelerometer (Actigraph®) to monitor nocturnal activity in shelter dogs every night during the full first two weeks in-shelter starting directly at shelter intake, as a measure of welfare. Additionally, urinary cortisol/creatinine ratio (UCCR), body weight and behaviour data were collected to evaluate stress responses. A control group of pet dogs in homes, matched to the shelter dog group, was also monitored. Shelter dogs had higher nocturnal activity and UCCRs than pet dogs, especially during the first days in the shelter. Nocturnal activity, both accelerometer measures and activity behaviour, and UCCRs decreased over nights in the shelter. Smaller dogs had higher nocturnal activity and UCCRs than larger dogs and showed less autogrooming during the first nights. Dogs with no previous kennel experience had higher nocturnal activity and UCCRs, and showed less body shaking, than dogs with previous kennel experience. Overall, sheltered dogs also showed less body shaking during the first night. The number of dogs showing paw lifting decreased over days. Age class and sex effected only few activity behaviours. Shelter dogs significantly lost body weight after 12 days in the shelter compared to the moment of intake. Shelter dogs had disrupted nocturnal resting patterns and UCCRs compared to pet dogs and seem to partly adapt to the shelter environment after two weeks. Sensor-supported identification of nocturnal activity can be a useful additional tool for welfare assessments in animal shelters.

Factors regarding the dog owner's household situation, antisocial behaviours, animal views and animal treatment in a population of dogs confiscated after biting humans and/ or other animals.

To examine the dog ownership factors characteristic to a population of dogs confiscated after a human and/ or animal-directed biting incident, we compared bite risk assessment reports of 159 confiscated dogs in the time frame 2008, 2009, 2010 (tf1) and of 215 confiscated dogs in the time frame 2020, 2021, 2022 (until mid-May; tf2). The reports were compiled by the same institute in a standardized format. We studied frequencies and chi-square pairwise comparisons (P<0.05) for 30 identified ownership factors. Overall (tf1 and tf2), 1,308 ownership factors were mentioned in the reports and reports mentioning ≥5 factors were twice as frequent in tf2 (38%) than tf1 (16%). Our data suggest that nine factors may in particular serve as a warning signal for biting incidents, as these factors were most frequently (≥15%) prevalent in the total of reported cases: having a multiple dog household, a dog reportedly roaming a neighbourhood without an owner, a dog's care tasks being transferred, a short leash and muzzle obligation served to the owner for a dog, an isolated and/ or confined keeping of a dog, a dog owner's (suspected) substance abuse, a dog owner's (suspected) animal abuse, a dog owner aggressing at confiscation of the dog and a dog owner being reported on for antisocial behaviours such as intimidation. Particularly, a dog owner's aggressive or antisocial behaviours and previous obligations to muzzle and short leash a dog (in our dataset often inappropriately adhered to by owners), may indicate that a proportion of owners of confiscated dogs, may not always be willing and/ or capable to guarantee societal safety. The results show that identification of dog ownership factors, might be useful for establishing biting incident policies and further studies should be done on preventive measures and controls.

Evaluation of the Thermal Response of the Horns in Dairy Cattle.

Dairy cattle are typically disbudded or dehorned. Little is known, however, about the biological function and role of horns during thermoregulatory processes in cattle, and thus about the potential physiological consequences of horn removal. Anecdotal evidence suggests that dairy cow horns increase in temperature during rumination, and few studies on other bovid species indicate that horns aid thermoregulation. The objective of this study was, therefore, to elucidate a possible thermoregulatory function of the horns in dairy cattle. Using non-invasive infrared thermography, we measured the superficial temperature of the horns, eyes, and ears of 18 focal cows on three different farms in a temperate climate zone under various environmental circumstances. Observations of social and non-social behaviours were conducted as well. Based on environmental temperature, humidity, and wind speed, the heat load index (HLI) was calculated as a measure of the heat load experienced by a cow. The temperature of the horns increased by 0.18 °C per unit HLI, indicating that horns serve the dissipation of heat. Dehorned cows had higher eye temperatures than horned cows, though this result should be interpreted with caution as the low sample size and experimental setup prevent casual conclusions. We did not, however, find changes in horn temperature during rumination, nor with any other behaviours. Our study thus supports a role of horns in thermoregulation, but not related to rumination. These results should be considered when assessing the potential consequences of horn removal, a painful procedure.

Attitudes of clients of Dutch pest controllers towards animal welfare in the management of liminal rodents.

Rodent control tends to involve methods that cause animal suffering, but little attention has been paid to the animal welfare implications of rodent control. The aim of the current study was to gain insight into the opinions and attitudes of clients of Dutch pest controllers, regarding liminal rodents, rodent control, and rodent welfare. A better understanding of their attitudes may contribute to more ethical rodent management programmes. An online survey among 248 clients of Dutch pest controllers was carried out. Respondents, especially those within the agricultural sector, have a relatively negative attitude towards rats and mice. Respondents in the agricultural subgroup do not consider the welfare of liminal rodents important. They also think that the welfare impact of commonly used control methods is limited, and they have low tolerance levels for the presence of rodents. Respondents from other sectors have a far more positive attitude towards rats and mice, consider their welfare to be of greater importance, have a greater estimation of the welfare impact of control methods and show greater tolerance levels towards rodents. The respondents from the latter subgroup have a similar attitude compared to Dutch pest controllers participating in a previous survey. The findings of the current study firstly provide useful information for the further development and practical implementation of preventive control methods. Secondly, they provide input for a more animal-friendly rodent control and for the development of an assessment framework to support ethical decision-making. Finally, they can be helpful for further research and the communication and co-operation between professional pest controllers and their clients.

Glucocorticoids in relation to behavior, morphology, and physiology as proxy indicators for the assessment of animal welfare. A systematic mapping review.

Translating theoretical concepts of animal welfare into quantitative assessment protocols is an ongoing challenge. Glucocorticoids (GCs) are frequently used as physiological measure in welfare assessment. The interpretation of levels of GCs and especially their relation to welfare, however, is not as straightforward, questioning the informative power of GCs. The aim of this systematic mapping review was therefore to provide an overview of the relevant literature to identify global patterns in studies using GCs as proxy for the assessment of welfare of vertebrate species. Following a systematic protocol and a-priory inclusion criteria, 509 studies with 517 experiments were selected for data extraction. The outcome of the experiments was categorized based on whether the intervention significantly affected levels of GCs, and whether these effects were accompanied by changes in behavior, morphology and physiology. Additional information, such as animal species, type of intervention, experimental set up and sample type used for GC determination was extracted, as well. Given the broad scope and large variation in included experiments, meta-analyses were not performed, but outcomes are presented to encourage further, in-depth analyses of the data set. The interventions did not consistently lead to changes in GCs with respect to the original authors hypothesis. Changes in GCs were not consistently paralleled by changes in additional assessment parameter on behavior, morphology and physiology. The minority of experiment quantified GCs in less invasive sample matrices compared to blood. Interventions showed a large variability, and species such as fish were underrepresented, especially in the assessment of behavior. The inconclusive effects on GCs and additional assessment parameter urges for further validation of techniques and welfare proxies. Several conceptual and technical challenges need to be met to create standardized and robust welfare assessment protocols and to determine the role of GCs herein.

Perspectives for Buck Kids in Dairy Goat Farming.

To start milk production, dairy goats need to give birth at least once. While most female kids are reared to become the next generation of dairy goats, only a small proportion of male kids (buck kids) are reared with reproduction aims. The market for buck kid meat, especially within Northern European countries, is currently relatively small compared to the number of bucks born. Therefore, the purposes for buck kids are limited and a substantial proportion of buck kid meat is used for pet food. Due to the limited economic value of buck kids, farmers are faced with a dilemma. Although raising bucks costs more money than it yields, the birth of kids is a prerequisite for production of milk and should be seen as an investment for business-wise healthy dairy goat farming. In that perspective, dairy goat farmers have an ethical responsibility toward buck kids, as well. In this paper, we compare various scenarios of dealing with the issue of surplus male animals. We provide recommendations for the rearing of buck kids based on the sector's experience and current practice in the Netherlands. Reducing the number of surplus (male) offspring, e.g., by an optimized prolonged lactation management and/or by artificial insemination with sex-sorted semen, could alleviate the issue of low value buck kids. Killing surplus animals before or directly after birth, on the other hand, is met with increasing societal scrutiny. Initiatives to propagate a market for buck kid meat for human consumption are important to enable a suitable and sustainable production system. To maintain the health and welfare of goat kids, amongst other factors, sufficient and good quality colostrum, milk, and an appropriate diet as they grow older, needs to be provided. One option to assure the safeguarding of health and welfare of all goat kids are quality assurance schemes for milk production. These schemes make dairy farmers accountable for the health and welfare of all kids in the rearing period, including the provision of colostrum and adequate care for newborn buck kids. We conclude that the combination of reducing the number of surplus kids, increasing the demand for goat products, and quality assurance schemes that may help to safeguard the welfare of buck kids.

Incorporating inter-individual variability in experimental design improves the quality of results of animal experiments.

Inter-individual variability in quantitative traits is believed to potentially inflate the quality of results in animal experimentation. Yet, to our knowledge this effect has not been empirically tested. Here we test whether inter-individual variability in emotional response within mouse inbred strains affects the outcome of a pharmacological experiment. Three mouse inbred strains (BALB/c, C57BL/6 and 129S2) were behaviorally characterized through repeated exposure to a mild aversive stimulus (modified Hole Board, five consecutive trials). A multivariate clustering procedure yielded two multidimensional response types which were displayed by individuals of all three strains. We show that systematic incorporation of these individual response types in the design of a pharmacological experiment produces different results from an experimental pool in which this variation was not accounted for. To our knowledge, this is the first study that empirically confirms that inter-individual variability affects the interpretation of behavioral phenotypes and may obscure experimental results in a pharmacological experiment.

Inter-individual variability in habituation of anxiety-related responses within three mouse inbred strains.

Inter-individual variability in behavioral and physiological response has become a well-established phenomenon in animal models of anxiety and other disorders. Such variability is even demonstrated within mouse inbred strains. A recent study showed that adaptive and non-adaptive anxiety phenotypes (measured as habituation and/or sensitization of anxiety responses) may differ within cohorts of 129 mice. This variability was expressed across both anxiety- and activity-related behavioral dimensions. These findings were based however on re-analysis of previously published data. The present study therefore aimed to empirically validate these findings in 129 mice. In addition, we assessed such inter-individuality in two other strains: BALB/c and C57BL/6. Males of three mouse inbred strains (BALB/c, C57BL/6 and 129S2) were behaviorally characterized through repeated exposure to a mild aversive stimulus (modified Hole Board, 4 consecutive trials). Behavioral observations were supplemented with assessment of circulating corticosterone levels. Clustering the individual response trajectories of behavioral and endocrine responses yielded two multidimensional response types of different adaptive value. Interestingly, these response types were displayed by individuals of all three strains. The response types differed significantly on anxiety and activity related behavioral dimensions but not on corticosterone concentrations. This study empirically confirms that adaptive capacities may differ within 129 cohorts. In addition, it extends this inter-individual variability in behavioral profiles to BALB/c and C57BL/6. Whether these two sub-types constitute differential anxiety phenotypes may differ per strain and requires further study.

An individual based, multidimensional approach to identify emotional reactivity profiles in inbred mice.

BACKGROUND: Despite extensive environmental standardization and the use of genetically and microbiologically defined mice of similar age and sex, individuals of the same mouse inbred strain commonly differ in quantitative traits. This is a major issue as it affects the quality of experimental results. Standard analysis practices summarize numerical data by means and associated measures of dispersion, while individual values are ignored. Perhaps taking individual values into account in statistical analysis may improve the quality of results. NEW METHOD: The present study re-inspected existing data on emotional reactivity profiles in 125 BALB/cJ and 129 mice, which displayed contrasting patterns of habituation and sensitization when repeatedly exposed to a novel environment (modified Hole Board). Behaviors were re-analyzed on an individual level, using a multivariate approach, in order to explore whether this yielded new information regarding subtypes of response, and their expression between and within strains. RESULTS: Clustering individual mice across multiple behavioral dimensions identified two response profiles: a habituation and a sensitization cluster. COMPARISON WITH EXISTING METHOD(S): These retrospect analyses identified habituation and sensitization profiles that were similar to those observed in the original data but also yielded new information such as a more pronounced sensitization response. Also, it allowed for the identification of individuals that deviated from the predominant response profile within a strain. CONCLUSIONS: The present approach allows for the behavioral characterization of experimental animals on an individual level and as such provides a valuable contribution to existing approaches that take individual variation into account in statistical analysis.

Importance of Basic Research on the Causes of Feather Pecking in Relation to Welfare.

Feather pecking is a prominent issue in the commercial egg industry, associated with economic losses and welfare problems. A non-systematic literature search suggests that studies on feather pecking are predominantly concerned with applied research goals. That is to say, they aim to solve or diminish the effects of this problematic behavior by orienting towards practical approaches. The strong emphasis on this research approach has skewed our knowledge of the causes of feather pecking in relation to welfare. While the need for such research is high, there is an equivalent need for basic research that has not received corresponding effort. Also, current research predominantly focuses on the negative effects on the birds being pecked, whereas too little attention is given to the possible welfare problems of the peckers. We argue that more basic research is needed for obtaining comprehensive science-based knowledge of behavioral needs and abilities of hens, in particular with respect to behavioral problems that threaten their welfare.

Effects of buprenorphine, butorphanol or tramadol premedication on anaesthetic induction with alfaxalone in common marmosets (Callithrix jacchus).

OBJECTIVE: To investigate the clinical and physiological effects of intravenous (IV) alfaxalone alone or in combination with buprenorphine, butorphanol or tramadol premedication in marmosets. STUDY DESIGN: Prospective, randomized, blinded, crossover design. ANIMALS: Nine healthy marmosets (391 ± 48 g, 3.7 ± 2.2 years old). METHODS: Meloxicam 0.20 mg kg-1 subcutaneously, atropine 0.05 mg kg-1 intramuscularly (IM) and either buprenorphine 20 µg kg-1 IM (BUP-A), butorphanol 0.2 mg kg-1 IM (BUT-A), tramadol 1.5 mg kg-1 IM (TRA-A) or no additional drug (control) were administered to all marmosets as premedication. After 1 hour, anaesthesia was induced with 16 mg kg-1 alfaxalone IV. All animals received all protocols. The order of protocol allocation was randomized with a minimum 28 day wash-out period. During anaesthesia, respiratory and pulse rates, rectal temperature, haemoglobin oxygen saturation, arterial blood pressure, palpebral and pedal withdrawal reflexes and degree of muscle relaxation were assessed and recorded every 5 minutes. Quality of induction and recovery were assessed. Duration of induction, immobilization and recovery were recorded. Blood samples were analysed for aspartate aminotransferase, creatine kinase and lactate dehydrogenase concentrations. The protocols were compared using paired t tests, Wilcoxon's signed-rank test with Bonferroni's corrections and linear mixed effect models where appropriate. RESULTS: Out of nine animals, apnoea was noted in eight animals administered protocol BUP-A and two animals administered protocol BUT-A. With TRA-A and control protocols, apnoea was not observed. No other significant differences in any of the parameters were found; however, low arterial blood pressures and hypoxia occurred in TRA-A. CONCLUSIONS AND CLINICAL RELEVANCE: Our study employing different premedications suggests that the previously published dose of 16 mg kg-1 alfaxalone is too high when used with premedication because we found a high incidence of complications including apnoea (BUP-A), hypotension and hypoxaemia (TRA-A). Appropriate monitoring and countermeasures are recommended.

Mutilating Procedures, Management Practices, and Housing Conditions That May Affect the Welfare of Farm Animals: Implications for Welfare Research.

A number of mutilating procedures, such as dehorning in cattle and goats and beak trimming in laying hens, are common in farm animal husbandry systems in an attempt to prevent or solve problems, such as injuries from horns or feather pecking. These procedures and other practices, such as early maternal separation, overcrowding, and barren housing conditions, raise concerns about animal welfare. Efforts to ensure or improve animal welfare involve adapting the animal to its environment, i.e., by selective breeding (e.g., by selecting "robust" animals) adapting the environment to the animal (e.g., by developing social housing systems in which aggressive encounters are reduced to a minimum), or both. We propose adapting the environment to the animals by improving management practices and housing conditions, and by abandoning mutilating procedures. This approach requires the active involvement of all stakeholders: veterinarians and animal scientists, the industrial farming sector, the food processing and supply chain, and consumers of animal-derived products. Although scientific evidence about the welfare effects of current practices in farming such as mutilating procedures, management practices, and housing conditions is steadily growing, the gain in knowledge needs a boost through more scientific research. Considering the huge number of animals whose welfare is affected, all possible effort must be made to improve their welfare as quickly as possible in order to ban welfare-compromising procedures and practices as soon as possible.

Bleeding Diathesis in Fawn Hooded Rats-Possible Implications for Invasive Procedures and Refinement Strategies.

The Fawn hooded (FH) rat is commonly used in biomedical research. It is widely acknowledged that the FH rat has a bleeding disorder; leading to abundant bleedings. Although this bleeding disorder is investigated to model the storage pool defect; its impact on commonly performed invasive laboratory procedures has not yet been described. Our research group experienced clinically significant consequences of this bleeding disorder following invasive procedures (including intraperitoneal injections and neurocranial surgery) in the Rjlbm: FH stock. The clinical consequences of the surgical and anesthetic protocols applied; are described including the subsequent procedural refinements applied to minimize the impact of this disorder. It is strongly recommended to take the bleeding diathesis into account when performing invasive procedures in FH rats and to apply the suggested refinement of procedures.

The modified hole board--measuring behavior, cognition and social interaction in mice and rats.

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure multiple dimensions of unconditioned behavior in small laboratory mammals (e.g., mice, rats, tree shrews and small primates). This paradigm is a valuable alternative for the use of a behavioral test battery, since a broad behavioral spectrum of an animal's behavioral profile can be investigated in one single test. The apparatus consists of a box, representing the 'protected' area, separated from a group compartment. A board, on which small cylinders are staggered in three lines, is placed in the center of the box, representing the 'unprotected' area of the set-up. The cognitive abilities of the animals can be measured by baiting some cylinders on the board and measuring the working and reference memory. Other unconditioned behavior, such as activity-related-, anxiety-related- and social behavior, can be observed using this paradigm. Behavioral flexibility and the ability to habituate to a novel environment can additionally be observed by subjecting the animals to multiple trials in the mHB, revealing insight into the animals' adaptive capacities. Due to testing order effects in a behavioral test battery, naïve animals should be used for each individual experiment. By testing multiple behavioral dimensions in a single paradigm and thereby circumventing this issue, the number of experimental animals used is reduced. Furthermore, by avoiding social isolation during testing and without the need to food deprive the animals, the mHB represents a behavioral test system, inducing if any, very low amount of stress.

Evaluation of ultrasonic vocalizations in common marmosets (Callithrix jacchus) as a potential indicator of welfare.

The vocal repertoire in common marmosets (Callithrix jacchus) has been assumed to consist not only of vocalizations audible to humans but also of ultrasonic vocalizations (USVs). The use of USVs to socially indicate distress has not been evaluated in this species, however. The authors analyzed the ultrasonic vocal repertoire of the common marmoset under normal housing conditions, under various experimental manipulations intended to elicit positive or negative emotional responses and during stressful experiences including blood draw and exposure to a perceived predator. Analysis of the recordings showed that marmosets produced vocalizations with ultrasonic components as part of their normal vocal repertoire, but these vocalizations all have audible components as well. Only 4 of the 13 types of vocalizations had ultrasonic components. These ultrasonic components were not reliably associated with responses to different experimental manipulations, suggesting that they are not used to indicate pain, discomfort or distress.

Modelling Alzheimer-like cognitive deficits in rats using biperiden as putative cognition impairer.

To enable the development of effective treatments for dementias such as Alzheimer's disease (AD), it is important to establish valid animal models of cognitive impairments. Scopolamine is widely used to induce cognitive deficits in animal models of AD, but also causes non-cognitive side effects. We assessed whether biperiden, a selective antagonist of M1 muscarinic receptors, which are predominantly expressed in brain areas involved in cognitive processes, causes cognitive deficits without inducing peripheral side-effects. Two different doses of biperiden (3 or 10mgkg(-1)) on the acquisition of a spatial cone field task were assessed in male Lister Hooded rats. This task measures, among others, spatial working (WM) - and reference memory (RM) simultaneously. Biperiden did not impair learning of the task. The animals reached asymptotic levels for all variables except reference memory and the number of rewards collected. However, the 10mgkg(-1) dose decreased the tendency of rats to use searching strategies to solve the task and made them slower to start searching and completing the task. In conclusion, though no effects on WM and RM performance were seen, the present study cannot conclude that biperiden acts as a more selective cognition impairer than scopolamine in other rats strains and/or other doses than those tested.

Chronic social stress does not affect behavioural habituation in male CD1 mice.

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

Sex Differences in Physiological Acclimatization after Transfer in Wistar Rats.

Most laboratory animals used in research are vendor-bred and transferred to research facilities. Transfer procedures might have considerable and unintended effects on research results. In the present study we compared physiological and behavioral parameters before and after external and internal transfer, as well as between transferred and non-transferred Wistar rats. The impact of both external and internal transfer on body weight, plasma corticosterone levels, heart rate, blood pressure, and locomotor activity was studied in both male and female Wistar rats, taking into account the sex differences in stress responsivity. External transfer was found to decrease body weight, increase plasma corticosterone, increase activity, increase heart rate in female rats, but decrease heart rate in male rats. Parameters showed differences between the sexes and light phases. This study shows that acclimatization after transfer is sex-specific and researchers should take the sex into consideration when determining the acclimatization period. It is recommended to allow for acclimatization of at least 8 days in males and two weeks in females after external transfer and timely (2 days before starting experiments) transfer the animals internally to the testing room.