bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing the Welfare Status of Newborn Farm Animals
Authors: Mellor D J , Stafford K J
Published: January 2023

Although major progress has been made during the last 50 years in understanding the causes of, and devising methods to minimise, neonatal mortality and morbidity in farm animals, almost all of this progress has been made without an explicit animal welfare focus. Nevertheless, knowledgeable intervention at birth now markedly reduces the total amount of animal welfare compromise that would otherwise occur. In assessing the degree of welfare compromise in other contexts three orientations are apparent. These emphasise biological function, affective state and natural living. In the present paper the significance of these orientations in an assessment of welfare compromise in newborn lambs, kids, calves, deer calves, foals and piglets, conducted previously, is examined. It is concluded that: 1) it was appropriate to emphasise biological function during the research which improved the management of newborns, but this emphasis was not sufficient to characterise the nature and degree of welfare compromise the newborn might experience; 2) a focus on affective state, and particularly on noxious sensations, more appropriately allowed an initial assignment of different degrees of compromise caused by neonatal breathlessness, hypoxia, hunger, sickness and pain; and 3) the notion that farm animals should be left to fend for themselves in a natural state at the time of birth when knowledgeable intervention would markedly reduce neonatal suffering contradicts our duty to care for the animals in our control. Finally, on-farm assessments of neonatal welfare compromise would be possible, but they would need to allow for the prevalence and severity of each condition, which can vary widely depending on the species and local circumstances.
Assessment of the impact of government animal welfare policy on farm animal welfare in the UK
Authors: Bennett RM , Broom DM , Henson SJ , Blaney RJP , Harper G
Published: January 2023

The paper presents the method and findings of a Delphi expert survey to assess the impact of UK government farm animal welfare policy, farm assurance schemes and major food retailer specifications on the welfare of animals on farms. Two case-study livestock production systems are considered, dairy and cage egg production. The method identifies how well the various standards perform in terms of their effects on a number of key farm animal welfare variables, and provides estimates of the impact of the three types of standard on the welfare of animals on farms, taking account of producer compliance. The study highlights that there remains considerable scope for government policy, together with farm assurance schemes, to improve the welfare of farm animals by introducing standards that address key factors affecting animal welfare and by increasing compliance of livestock producers. There is a need for more comprehensive, regular and random surveys of on-farm welfare to monitor compliance with welfare standards (legislation and welfare codes) and the welfare of farm animals over time, and a need to collect farm data on the costs of compliance with standards.
Stereotypic swaying and serum Cortisol concentrations in three captive African elephants (Loxodonta africana)
Authors: Wilson ML , Bloomsmith MA , Maple TL
Published: January 2023

The behaviour and serum Cortisol concentrations of three captive female African elephants(Loxodonta africana)were studied to determine whether their stereotypic swaying was more prevalent before regularly scheduled events in the elephants’ routine, and whether the elephants that exhibited more stereotyped swaying had lower mean serum cortisol concentrations. Behavioural data were collected during hour-long observations balanced across three periods, and during 15-min observations prior to the elephants being moved to different portions of their enclosure. Observational data were collected using instantaneous focal sampling of behaviours every 30s. Serum cortisol measures were obtained through weekly blood withdrawal from the elephants’ ears. Of the three elephants, two exhibited stereotyped swaying, which accounted for a mean of 0.4% of the scans during the hour-long observations and a mean of 18% of the scans prior to the elephants being moved between different parts of the enclosure. Swaying was highly variable among the individual elephants during both categories of observations. Additionally, both elephants swayed more prior to moving in the afternoon than prior to moving in the morning. Analyses of serum cortisol concentrations indicated that each elephant had a different mean cortisol level, which did not clearly correspond with the expression of swaying. The findings indicate that a rigidly scheduled management event may elicit stereotyped swaying in the studied elephants. Future research should document the behavioural and physiological effects of an altered management routine to improve captive elephant welfare.
Non-lethal control of fox predation: the potential of generalised aversion
Authors: Macdonald DW , Baker SE
Published: January 2023

Traditionally, game-keepers and agriculturalists have controlled predators using lethal methods, but there are circumstances under which these may be ineffective or inappropriate for animal welfare or conservation reasons. Generalised aversion is potentially a form of non-lethal control, in which predators are conditioned to avoid foul-tasting bait, causing them subsequently to generalise this avoidance to similar, but untreated, prey, thereby affording it protection. In this exploratory study, a group of captive red foxes(Vulpes vulpes)was successfully conditioned to avoid untreated milk after drinking milk containing BitrexTM, a bitter substance that they were unable to detect except by taste. Our foxes were members of a family group and so housed together to reduce stress, and therefore the individuals’ responses to the various treatments may not have been independent. As a result, we combined data from the three animals, and our most conservative analyses consider the sampling population to be this fox group; we do not make inferences about foxes in general, but confine them to this fox-group. This trial was a pilot to reveal the potential for future work on wild animals. Successful application of generalised aversion to non-lethal predator control has far-reaching implications for the sport hunting industry, nature reserve management and the conservation of threatened predators requiring control, as well as clear animal welfare benefits.
Peri-natal environmental effects on maternal behaviour, pituitary and adrenal activation, and the progress of parturition in the primiparous sow
Authors: Jarvis S , Reed BT , Lawrence AB , Calvert SK , Stevenson J
Published: January 2023

Maternal behaviour in free-ranging sows is normally performed in an isolated nest that the sow has built during the pre-parturient period. Consequently there is much concern over the use of restrictive farrowing crates, in which manipulable substrates are often not provided, for parturient sows under commercial conditions. This study examined the impact of the provision of space and substrate on the performance of maternal behaviour by gilts (primiparous sows) on physiological indicators of stress and on the progress of parturition. Gilts had an indwelling jugular catheter implanted 12 days before their expected farrowing date. At 5 days before expected farrowing, 34 gilts were placed in one of four farrowing treatments: crate without straw (C, n = 8), crate with straw (CS, n = 9), pen without straw (P, n = 9) or pen with straw (PS, n = 8). Behavioural observations of gilts and piglets were made during an 8 h period after the expulsion of the first piglet. Blood samples were taken via a catheter extension to minimise disturbance throughout the parturition period. Gilts in all treatments were most active in the first 2 h: performing more standing/walking, substrate-directed and piglet-directed behaviour. This active phase was followed by inactivity and passivity, as has been seen in free-ranging sows. However, this temporal profile of behaviour was more pronounced in the penned gilts (P and PS), which were more active during the first 2 h than the crated gilts (C and CS). Gilts in crates spent longer sitting throughout the 8 h period and tended to show more savaging of their piglets. Savaging gilts were found to be more active and responsive to piglets. The provision of straw did not alter gilt behaviour but did alter piglet behaviour, with piglets that were born into environments with no straw (C and P) spending more time next to the gilt's udder. The provision of straw increased the length of parturition (CS and PS), but this did not have detrimental effects on piglet survival. Plasma cortisol was unaffected by space or substrate, however, plasma ACTH was found to be highest in C gilts during the second hour of parturition. Plasma oxytocin was unaffected by space or substrate, however, there was a positive relationship between plasma oxytocin and unresponsiveness to piglets. In conclusion, it appears that farrowing crates thwart interactions between the gilt and her piglets, and that the provision of space during parturition, irrespective of straw availability, facilitates the performance of maternal behaviour that more closely resembles that performed by free-ranging sows.
Benefits of positive human interaction for socially housed chimpanzees
Authors: Baker KC
Published: January 2023

Human interaction as environmental enrichment for chimpanzees (Pan troglodytes) and other primates is widely promoted and believed to be of value, but has been subject to little objective evaluation. This study assessed the effects of positive human interaction (eg relaxed treat feeding, playing, and other forms of social interaction compatible with personnel safety) on the behaviour of adult chimpanzees. Subjects were housed indoors in groups of two or three individuals. The level of interaction during routine care and management (ie in the process of cleaning, feeding, and monitoring) represented the baseline condition. The test condition involved a familiar caretaker spending an additional 10 mins per day, 5 days a week, with each chimpanzee. This study was designed to assess carry-over effects of interaction on behaviour outside the context of care staff presence. Therefore, in all phases of the study, data (97 h of focal animal sampling) were collected only when caretakers were absent from the building. During the increased human interaction phase, the chimpanzees groomed each other more and showed lower levels of the following behaviours: regurgitation/reingestion, other oral abnormal behaviours, inactivity, and reactivity to the displays of neighbouring groups. A trend towards reduced agonistic display was also detected. Attempted interactions with the observer shifted significantly from predominantly aggressive to predominantly affiliative in nature. These results suggest that simple, unstructured affiliation between humans and chimpanzees should be a valued component of behavioural management.
A survey assessment of the incidence of fur-chewing in commercial chinchilla(Chinchilla lanigera)farms
Authors: Ponzio MF , Busso JM , Ruiz RD , de Cuneo M Fiol
Published: January 2023

Chinchilla lanigeraintensive breeding programmes are affected by an abnormal repetitive behaviour called ‘fur-chewing’, yet the aetiology is still unknown and little scientific work has been published on this condition. Recent studies have supported the idea that fur-chewing is a stress-related behaviour. In the present study, we used a questionnaire survey in order to: 1) describe general aspects on the epidemiology of fur-chewing in Argentinian farms, and 2) identify which management and/or environmental factors within the breeding facilities may be influencing the occurrence of fur-chewing. The survey consisted of 28 questions focused on farm characteristics, environmental variables and husbandry routines, and was distributed to Argentinian chinchilla farmers. All quantitative variables were tested in a multiple logistic regression model. The mean incidence of fur-chewing was 4.32 ± 0.37% (n = 107 farms). Variables negatively related to fur-chewing were the breeder experience in the activity, the total volume of the facility, and the number of wood shaving changes per week. Positive relationships were found for space index, number of rooms in the facility and presence of different rooms for fur production and reproduction. Other tendencies suggested that farms with the presence of external sound disturbance nearby had higher incidence levels. Also, we detected a tendency towards lower numbers of affected animals with an increment in the provision of dusting baths per week. Finally, results suggested a female prevalence in the development of the behaviour.
A Guide for Lay Members of Animal Ethics Committees
Authors: Wickens S
Published: January 2023

This brief guide (see details below) gives an overview of Animal Ethics Committees (AECs) and the role of the lay member in these. In particular, it seeks to reassure concerns that lay members, especially those lacking experience in the area, may have about their importance and legitimacy in the ethical review process. After detailing the role of AECs under New Zealand legislation as it relates to the use of animals in research, testing and teaching, the guide then highlights four factors: independence, public representation, animal advocacy and the possession of a fresh perspective as the most important elements contributed by lay members to the review process. What follows is the now customary explanation of the principle of the 3Rs and how they underline the human use of animals in science and teaching, and then helpful suggestions as to questions and issues that a lay member should consider when assessing a proposal. Finally, a short glossary of terms and references are given. As a guide, it acts as a useful introduction for lay members, but anyone seeking to fulfill this role to the best of their abilities will want to utilise the references given to better understand the issues and concerns more deeply.
Operant animal welfare: productive approaches and persistent difficulties
Authors: Patterson-Kane EG , Pittman M , Pajor EA
Published: January 2023

Operant procedures occupy a prominent role within animal welfare science because they provide information about the strength of animals’ preferences. It is assumed that strongly motivated choices commonly indicate conditions necessary for uncompromised welfare. A review of the literature shows that members of many species will work for access to resources not commonly provided to them; including a secure resting place (perches for hens or boxes for rodents) and substrates for species-typical activities such as nesting, digging and rooting (in hens, rats, mice and pigs). Despite a recent surge in popularity, operant techniques remain under-utilised and studies employing them struggle to find the best method for prioritising resources. In order to fully exploit the potential of operant procedures a wider appreciation of the relevant theories and techniques might be beneficial; including greater employment of the basic principles of reinforcement theory and further development of more complex economic analogies. If these two strands of research develop together, operant approaches have a key role to play in refining and replacing husbandry practices that undermine animal welfare.
Communication from the Commission to the European Parliament and the Council on the Various Systems of Rearing Laying Hens in Particular Those Covered by Directive 1999/74/EC
Authors: Carter E
Published: January 2023

Directive 1999/74/EC recognised three farming methods for rearing laying hens within the European Union (EU): unenriched cages, enriched cages and alternative systems. The Directive came into force in July 1999 with the aim of protecting laying hen welfare by setting out a core set of minimum standards. Article 10 of these regulations required the European Commission (EC) to submit to the Council a report based on scientific opinion and covering the various rearing systems for laying hens, taking into account pathological, zootechnical, physiological and ethological aspects as well as environmental and health impacts. The report was also required to incorporate the socio-economic implications of the various systems and their effects on the European Communities economic partners.
Post-release survival of hand-reared pipistrelle batsPipistrellusspp)
Authors: Kelly A , Goodwin S , Grogan A , Mathews F
Published: January 2023

There is very little known about the post-release survival of hand-reared pipistrelle batsPipistrellusspp). We radio-tracked 12 pipistrelle bats, hand-reared and released under three different protocols: i) limited pre-release flight training and overwintering (n = 5); ii) prolonged pre-release flight training, but with limited space (n = 2) and iii) prolonged pre-release flight training in large flight cage (n = 5). Of the five bats reared under the first protocol, four were recovered, grounded, within 48 h and the signal from the fifth bat lost on day two, due either to tag failure or from the bat flying out of the study area. Both bats in the second group flew strongly on the night of release but on the second and third nights only one emerged and flew briefly. The signals from both bats remained stationary on subsequent nights. In contrast, bats from the third group were tracked for between five and ten nights, indicating that they were able to survive independently following release. These preliminary results suggest that post-release survival depends on extensive pre-release conditioning in a large flight cage, rather than the limited flight opportunities traditionally provided within domestic houses by bat carers. Other factors that may affect post-release survival are discussed and further work is encouraged to determine whether rehabilitated bats integrate with the local population.
The Welfare Implications of Shepherding During Lambing in Extensive New Zealand Farming Systems
Authors: Fisher M W , Mellor D J
Published: January 2023

A review of the literature was undertaken to consider the possible effects of human intervention (shepherding) at around the time of parturition in extensively farmed sheep. There is little clear empirical evidence to suggest that shepherding ensures either easy births or the integrity of ewe–lamb contact — factors closely linked to the welfare of the animals at this time. There is similarly no clear support for shepherding being harmful. However, the following suggestions are made: first, human presence can inhibit or delay parturition; second, extended parturition can increase the risk of, or is associated with, dystocia; and third, disturbance at birth can compromise ewe-lamb bonding and consequently lamb survival. Furthermore, sheep populations that have undergone rigorous selection for ease of lambing and minimal shepherding in extensive environments have well-documented physical and behavioural traits underlying their predisposition for enhanced lamb survival. Although our cultural legacy may impose a duty to intensively monitor animals at lambing, it is concluded that, at least in some situations, shepherding may not be entirely beneficial. The commonly held view of the necessity for some human intervention in extensive livestock systems is perhaps overly paternalistic, and requires a more comprehensive appraisal.
Regulation of Free-Roaming Cat(Felis Silvestris Catus)Populations: A Survey of the Literature and Its Application to Israel
Authors: Gunther I , Terkel J
Published: January 2023

Following domestication of the cat about 5000 years ago, it followed man into many areas of the world. The vast resources available in urban environments have led to increasing numbers of free-roaming cats on the streets. The high population density of these cats and, in many cases, the lack of suitable nourishment and veterinary care, is conducive to their poor condition of health. They are frequently perceived as a nuisance to human society. This article surveys the different methods of management of free-roaming cat populations, focusing on the urban environment, and discusses the animal welfare implications and the advantages and disadvantages of each method.
Lying behaviour and adrenocortical response as indicators of the thermal tolerance of pigs of different weights
Authors: Hillmann E , Mayer C , Schrader L
Published: January 2023

The aim of this study was to assess optimal temperature ranges for fattening pigs of different weights kept in pens with partially slatted floors. We examined the behavioural and adrenocortical responses of pigs of different weights (25–35 kg, 50–70 kg, and >85 kg) to a wide range of ambient temperatures (2–29°C). On three days of each experimental period, we took saliva samples for the analysis of cortisol concentration, and recorded lying behaviour from 0800–0600h. Behavioural and cortisol parameters were analysed using linear mixed effects models. Optimal temperature ranges for the three weight-classes were calculated using logistic regression. Pigs chose different areas for resting depending on ambient temperature. With increasing temperature, pigs used the dung area more often and lay more often without contact with pen mates. Compared to lighter pigs, heavier pigs lay without contact with pen mates at lower temperatures. In general, lying without contact occurred at temperatures 5–7°C lower than lying in the dung area. Huddling increased with decreasing temperature, and, with increasing weight, pigs showed huddling at lower temperatures. There was a significant increase in cortisol levels at high ambient temperatures in pigs >85 kg. In pens with partially slatted floors, the results indicate temperature ranges within the thermal tolerance of pigs to be 19–21°C for pigs weighing 25–35 kg (lying area of 0.46 m2/pig), 10–17°C for pigs between 50–70 kg and 5–17°C for pigs >85 kg (both weights: lying area of 0.67 m2/pig).
The effect of transport stress on neutrophil activation in wild badgers(Meles meles)
Authors: Montes I , McLaren GW , Macdonald DW , Mian R
Published: January 2023

Wild badgers (Meles meles) in Wytham woods, Oxfordshire, are routinely trapped, transported to a central field laboratory, studied and released as part of an on-going population study. These procedures have been carefully developed to minimise impact on the badgers' welfare; however they are potentially stressful, and, as part of our on-going welfare refinements, and our exploration to develop methods for quantifying stress in wild mammals, we studied the effects of transport stress on neutrophil activation in wild trapped badgers. Blood samples were obtained from 28 badgers. We compared three transport regimes: transported (n = 9), transported and rested for at least 30 mins (n = 11), and not transported (n = 8). Total and differential white cell counts were carried out and neutrophil activation was measured by the nitroblue tetrazolium test. Our goal was primarily to validate neutrophil activity as an indicator of stress, on the basis that the transport treatment was expected to be more stressful than the non-transport treatment. There were significant increases in % activated circulating neutrophils in response to transport. This study supports the proposition that stress affects circulating neutrophil numbers and the state of their activation, as determined by the nitroblue tetrazolium reduction assay, and therefore adds weight to the idea that neutrophil activation is a potential measure of stress in wild animals.
Computer-assisted enrichment for zoo-housed orangutans (Pongo pygmaeus)
Authors: Tarou LR , Kuhar CW , Adcock D , Bloomsmith MA , Maple TL
Published: January 2023

The study of environmental enrichment has identified a variety of effective forms of enrichment, but there are widespread problems associated with their use. Few forms of enrichment are cognitively challenging, and even the most effective often result in rapid habituation. This study examined the use of a computer-joystick system, designed to increase in complexity with learning, as a potential form of enrichment. Eight orangutans (Pongo pygmaeus), housed in male/female pairs, were observed for 120 h during a baseline period and 120h when the computer-joystick apparatus was available. Data were collected in 1 h sessions using instantaneous group scan sampling with 30 s intervals. The orangutans spent 25.9% of the scans using the joystick system. One member of each pair monopolised the computer system: ‘high users’ spent 48.9% of scans using the joystick system compared with 2.9% by ‘low users’. Behavioural changes associated with the provision of the computer included increases in aggressive behaviour, anxiety-related behaviours, solitary play, contact with and proximity to a social partner, and decreases in feeding. The lack of habituation by the high users, both within and across sessions, indicates that computer-assisted tasks may be a useful form of environmental enrichment for orangutans. However, the significant increase in aggression indicates that this form of enrichment may be more suitable for singly caged animals, or that the provision of multiple apparatuses should be tested for the ability to eliminate potential competition over the device.
Measuring the value to the public of pig welfare improvements: a contingent valuation approach
Authors: Glass CA , Hutchinson WG , Beattie VE
Published: January 2023

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.
Faecal glucocorticoid level is not correlated with stereotypic pacing in two captive margays (Leopardus wiedii)
Authors: Gusset M
Published: January 2023

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.
Genetically modified animals in research: an analysis of applications submitted to ethics committees on animal experimentation in Sweden
Authors: Nordgren A , Röcklinsberg H
Published: January 2023

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.
The Three Rs: past, present and future
Authors: Russell WMS
Published: January 2023

“Our story must begin with Charles Hume, for the whole of this grand enterprise began as a twinkle in his eye, which often twinkled” (Russell 1995). Fifty-one years ago, in 1954, besides important achievements in other fields of animal welfare, Hume and the Universities Federation for Animal Welfare (UFAW) had brought out the first edition ofThe UFAW Handbook on the Care and Management of Laboratory Animals, edited by Alastair Worden (Worden 1947), who was already preparing a greatly enlarged second edition with William Lane-Petter (Worden & Lane-Petter 1957). Hume had already contributed to the first edition of the Handbook an article on statistical analysis, which is clearly relevant to actual experimentation (Hume 1947); he now had the brilliant and totally original idea of starting ageneralstudy of humane technique in actual experimentation. The late Rex Burch and I were appointed to undertake this project; the moment Rex walked into my office I knew that here was not only the perfect colleague but also a lifelong friend, and I sadly miss him.
Assessment of stress in non-human primates: application of the neutrophil activation test
Authors: Honess PE , Marin C , Brown AP , Wolfensohn SE
Published: January 2023

A technique measuring leukocyte (neutrophil) activity was used to examine differences between stress levels in a breeding colony of rhesus macaques housed in either a traditional caging system or open-rooms. The leukocyte activation test measured the degree to which blood from the two treatment groups could launch a further neutrophil response (superoxide production) to anin vitrochallenge. Animals housed in a traditional caging system produced a significantly lower leukocyte response than animals housed in open-rooms, indicating that there was a higher level of stress associated with caged housing than open-room housing. This was not influenced by whether animals were physically restrained or trained to stand for a sedating injection. No differences were found between treatment groups in leukocyte numbers or composition. This study validates the use of the leukocyte activation test to assess physiological stress levels in non-human primates and demonstrates the animal welfare benefits of open-room housing over traditional laboratory caging systems.
An illustration that statistical design mitigates environmental variation and ensures unambiguous study conclusions
Authors: Gore KH , Stanley PJ
Published: January 2023

This paper highlights the essential need for appropriate statistical design and randomisation in laboratory animal studies. Using an example of a 21 day weight gain study in mice, we show that without the use of an appropriate statistical design and randomisation, incorrect conclusions may have been drawn. We used an experimental design that allowed comparisons to be made between five treatments that were free from systematic error. Two alternative designs that are practically attractive, yet had no statistical basis, are also described in this paper and the potentially incorrect conclusions highlighted. The use of appropriate statistical design is ethical because it results in clear, unambiguous conclusions. Conclusions that may be biased or ambiguous will require verification by further research and this, in the long term, is contrary to the reduction element of the Three Rs.
The Three Rs in the pharmaceutical industry: perspectives of scientists and regulators
Authors: Fenwick NP , Fraser D
Published: January 2023

Six drug regulatory reviewers and 11 pharmaceutical industry scientists were interviewed to explore their perspectives on the obstacles and opportunities for greater implementation of the Three Rs (replacement, reduction, refinement) in drug research and development. Participants generally supported the current level of animal use in the pharmaceutical industry and viewed in vitro methods as supporting, but not replacing, the use of animals. Obstacles to greater use of the Three Rs cited by participants included the lack of non-animal alternatives; requirements for statistical validity; reluctance by industry and regulators to depart from established patterns of animal use; the priority of commercial objectives ahead of the Three Rs; and concern that less animal testing could jeopardise human safety. Opportunities identified for the Three Rs included the development of better animal models including genetically modified (GM) animals; pursuit of more basic knowledge, notably drug action on gene expression; re-use of animals; greater use of pilot studies; using sufficient numbers of animals per test to avoid repeating inconclusive studies; regular review of animal data in regulatory requirements; and following the regulatory option of combining segments of reproductive toxicology studies into one study. In some areas, greater implementation of the Three Rs seemed well aligned with industry priorities, for example, phenotypic characterisation of GM animals and validation of alternative methods. In other areas, wider use of the Three Rs may require building consensus on areas of disagreement including the usefulness of death as an endpoint; the suitability of re-using animals; and whether GM animals and the use of pilot studies contribute to reduction.
The effects of amount and frequency of alternating current used in water bath stunning and of slaughter methods on electroencephalograms in broilers
Authors: Raj ABM , O'Callaghan M , Knowles TG
Published: January 2023

The effectiveness of electrical water bath stunning of 172 individual broilers for 1 s with a constant root mean square (RMS) current of 100, 150 or 200 mA, delivered using a variable voltage/constant current stunner with 200, 400, 600, 800, 1000, 1200 or 1400 Hz sine wave alternating current (AC), followed by slaughter using a unilateral or ventral neck-cutting procedure, was evaluated. A binary logistic regression of broilers showing epileptiform activity or not following stunning showed that both the electrical frequency (Hz) and RMS current (mA) had a significant effect on the probability of the electroencephalogram (EEG) manifestation. The univariate analysis of variance showed that the time to the onset of less than 10% of the pre-stun relative power contents was significantly affected only by the interaction between electrical frequency and slaughter method. A similar analysis of variance of the time to reach less than 10% of the pre-stun total power content showed slaughter method, RMS current, the slaughter method/frequency interaction and the RMS current/frequency interaction to be either significant or approaching significance. Based on these results it is recommended that effective water bath stunning of broilers with a minimum constant current of 100, 150 and 200 mA could be achieved with electrical frequencies of up to 200, 600 and 800 Hz, respectively. In addition, It is likely that electrical frequencies of above 800 Hz would have required a minimum current of greater than 200 mA to induce epileptiform activity in the EEGs of broilers.
The effects of pulse width of a direct current used in water bath stunning and of slaughter methods on spontaneous electroencephalograms in broilers
Authors: Raj ABM , O'Callaghan M , Hughes SI
Published: January 2023

The effect of the pulse width of a direct current (DC) on the effectiveness of electrical water bath stunning, and slaughter, was evaluated in broilers (n = 29). Broilers were individually stunned in a water bath for 1 s with a constant peak current of 400 mA of 200 Hz DC delivered using a variable voltage/constant current stunner. The pulse width of the 200 Hz DC was set at 0.5, 1.5 or 2.5 ms (10, 30 or 50% of 5 ms current cycle). The results showed that pulse width had a significant effect on the incidence of epileptiform activity in the electroencephalograms (EEGs). A pulse width of 10% of the current cycle was less effective than pulse widths of 30 and 50% of the current cycle; there was no significant difference between a pulse width of 30 and 50%. The results of a univariate analysis showed that ventral neck-cutting resulted in a significantly shorter time to the onset of less than 10% of the pre-stun power contents in the 13–30 Hz and 2–30 Hz EEG frequency bands when compared with unilateral neck-cutting. It is concluded that a pulse width of 30 or 50% of the current cycle of 200 Hz DC, delivering 400 mA peak current, was better than using a pulse width of 10% of the current cycle.
Immediate immobilisation of a Minke whale using a grenade harpoon requires striking a restricted target area
Authors: Knowles TG , Butterworth A
Published: January 2023

Approximately 1500 Minke whales are killed annually under permit from the International Whaling Commission (IWC). This hunt supports a modest industry in Norway and in Japan; however, the welfare of whales during hunting and killing is such a cause of concern that in 1980 the IWC formed a sub-group entitled ‘Working Group on Whale Killing Methods and Associated Welfare Issues’ devoted to discussing the issue. This commentary suggests that, when using the Norwegian penthrite grenade-tipped harpoon (‘Whalegrenade-99‘), it is necessary to hit a relatively well-defined target area in order to effect an immediately immobile, and presumed unconscious state in the Minke whale.
A review of the welfare consequences of surgical castration in piglets and the evaluation of non-surgical methods
Authors: Prunier A , Bonneau M , von Borell EH , Cinotti S , Gunn M , Fredriksen B , Giersing M , Morton DB , Tuyttens FAM , Velarde A
Published: January 2023

Male piglets are castrated primarily to prevent the unpleasant odours and flavours of entire male pig meat (boar-taint). Although castration can be legally performed without analgesia in the first seven days of life, available evidence shows that castration at any age is painful and may have a detrimental influence on health. Few anaesthetics or analgesics are licensed for use in piglets. The known methods for general and epidural anaesthesia cannot be run at the farm level for practical and/or legal reasons. Use of the local anaesthetic lidocaine is easy and allows the pain resulting from castration to be alleviated. Local destruction of testicular tissue by intra-testicular injection of chemical compounds (salts and acids) is an alternative to surgical castration but needs further investigation regarding welfare improvement and boar taint reduction. Immunocastration, by which castration is achieved using active immunisation (anti–GnRH immunisation) is an efficient alternative to surgical castration; however, there are no licensed vaccines in the EU and the consequences, in terms of pig welfare as well as its acceptability among EU consumers, need further evaluation.
The effect of cover on food consumption and growth in two freshwater fish species used in experimental studies
Authors: Wootton RJ , Handisyde N , Rowe C
Published: January 2023

To define suitable holding conditions for fish used in experimental studies on food consumption and growth, the effect of cover on growth at two ration levels was quantified for immature individuals of two common, freshwater species: the threespine stickleback (Gasterosteus aculeatus: Gasterosteidae) and the European minnow (Phoxinus phoxinus: Cyprinidae). In the European minnow, the presence of cover significantly increased growth rates and also the rate of food consumption atad libitumrations; however, cover had no significant effect on the growth of the threespine stickleback. In both species, fish fedad libitumrations had higher growth rates than fish fed 4% of body weight per day. This study illustrates the need for species specific holding conditions and illustrates an approach to welfare using measurements of traits closely related to fitness.
Effects of aviary and box sizes on body mass and behaviour of domesticated budgerigars (Melopsittacus undulatus)
Authors: Gebhardt-Henrich SG , Steiger A
Published: January 2023

Forty-eight budgerigars (Melopsittacus undulatus) were pairwise housed in small (80 × 40 × 50 cm) and large (160 × 40 × 50 cm) (length × breadth × height) boxes, as well as in 2.0 × 1.0 × 2.0 m aviaries. All boxes and aviaries had two or three (aviaries) perches and food was offered on the bottom. The body masses of female budgerigars increased significantly when they were housed in boxes instead of aviaries. The size of the box did not influence body mass. The frequency of flying was adjusted to the size of the box as both males and females flew approximately twice as often from perch to perch in a small box than in a large box of double length. Flying behaviour differed significantly between large and small boxes and aviaries. The ratio of invariantly flying from perch to perch to all flying events increased from aviaries < large boxes < small boxes. About 75% of all flying events in small boxes consisted of flying from perch to perch. Females in boxes spent more time on the bottom where the food was placed than females in aviaries. Both the significant body mass gain in female budgerigars, as well as the invariant, stereotypic flying movements, indicated reduced welfare in budgerigars housed in boxes, compared with those in aviaries. Providing a large box did not prevent body mass gain, but did increase the variation in flying patterns. Under long-term housing conditions, boxes could lead to at least two serious welfare problems; obesity and stereotypic behaviour, and should be avoided for budgerigars. Therefore, aviary housing should be chosen wherever possible.
Long-term social memory in the laboratory rat (Rattus norvegicus)
Authors: Burman OHP , Mendl M
Published: January 2023

A key question in the management of group-housed captive animals is how long can an individual be removed from a social group and still be reintroduced with minimal social upheaval. In order to answer this question we require a knowledge of how long cage-mates, following a specified period of group-housing, can remember one another after separation. This issue was investigated in laboratory rats (Rattus norvegicus). Rats were group-housed for 18 days before being housed individually. One hour, 48 hr, and 96 hr after separation, they were exposed simultaneously to odour cues originating from unfamiliar rats and from former cage-mates. The rats spent significantly more time investigating the unfamiliar odour 1 hr and 48 hr, but not 96 hr, after separation, suggesting that, after 18 days of group-housing, juvenile rats remember former cage-mates for between 48 and 96 hr. The implications of this result for animal welfare are discussed.
Do double cages and access to occupational materials improve the welfare of farmed mink?
Authors: Hansen SW , Malmkvist J , Palme R , Damgaard BM
Published: January 2023

The effects of cage enrichments and additional space were studied in 60 pairs of mink kits kept in standard cages (STD) and 67 pairs of mink kits kept in enriched cages (ENR). During the period from mid July to the end of September both groups had alternate access to one and two connected cages. From October, half of the mink in each group had permanent access to one cage and the other half permanent access to two cages. The enrichment of the cages consisted of extra resting places (tubes made of wire mesh and plastic) and occupational materials in terms of table-tennis balls and ropes to pull and chew. The mink were observed for an experimental period of nine months, from late lactation until the beginning of the following mating season. The welfare was assessed through behavioural traits (use of nest box and enrichments, activity out in the cage, stereotypies and fur-chewing) consumption of food and straw, bodyweight and level of faecal corticoid metabolites. The presence of enrichments resulted in less tail-chewing, fewer stereotypies, and a reduced level of faecal corticoid metabolites. In addition, the presence of enrichments led to fewer social interactions and reduced the consumption of straw. Regarding the frequency of utilising different occupational materials, the mink did not use the table-tennis balls, but the tubes and pull-ropes were given extensive use. Access to one or double cages had no effect on stereotypies, fur-chewing and physiology linked to welfare, but mink with access to double cages used the nest box less, had a lower consumption of straw and pull-ropes than the mink with access to only one cage. However, there were no indications of frustration when the mink were deprived of using double cages. We conclude that increased environmental complexity in the form of occupational materials improved the welfare of the mink, whereas doubling the cage size had little or no effect in relation to mink welfare.
Behaviour of golden hamsters (Mesocricetus auratus) kept in four different cage sizes
Authors: Fischer K , Gebhardt-Henrich SG , Steiger A
Published: January 2023

Cages for laboratory and pet hamsters are usually small. Using video recordings, the behaviour of sixty female golden hamsters (Mesocricetus auratus), housed individually in four different cage sizes, was compared in order to draw conclusions about their welfare. The cage sizes were 1,800 cm2, 2,500 cm2, 5,000 cm2, and 10,000 cm2. Enrichment items and litter depth were standardised and all cages were equipped with a running-wheel (30 cm diameter). Stereotypic wire-gnawing, usage of the provided space, weight gain, and reactions to mild husbandry stressors were used as welfare indicators. Stereotypic wire-gnawing was observed in all cage sizes, but hamsters in small cages gnawed significantly longer and more frequently. There were no significant differences in running-wheel activity. In small cages hamsters made use of the roof of their wooden shelters as an additional platform more often than in big cages, which could suggest that they needed more space. Therefore, the welfare of pet golden hamsters in cages with a minimal ground floor area of 10,000 cm2seemed to be enhanced compared with smaller cages.