The inclusion of Russell and Burch's Three Rs (replacement, reduction and refinement) in guidelines, codes of practice and law reflects their current position as the guiding principles of ethical assessment of research involving animals. This article explores some activities within the contemporary livestock industry that constitute the experimental use of animals on a local and global scale. The elucidation of correlated responses during trait selection in genetic improvement programs provides one example of experiments occurring within the commercial livestock industry. This experimentation is largely conducted without scrutiny of its conformity to the Three Rs. Experimentation to improve the management of the livestock industry is consistent with the principle of refinement, and experimentation to increase productivity per unit of livestock is consistent with the principle of reduction; however, experimentation to increase total livestock production conflicts with the principle of replacement. Some approaches regarding the appraisal of the ethics of research involving animals, which could avoid arbitrary boundaries associated with the location or purpose of experimentation, are considered together with the relationship between experimentation and other anthropogenic impacts on animals.

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 effectiveness of electrical water bath stunning of broilers (n = 96) for 1 s with a constant average current of 100, 150 or 200 mA delivered using a variable voltage/constant current stunner with 200, 800 or 1400 Hz pulsed direct current (DC), with a mark:space ratio of 1:1, followed by slaughter using a unilateral or ventral neck cutting procedure, was evaluated. The results of a binary logistic model showed that both the electrical frequency and average current had significant effects on the probability of inducing epileptiform electroencephalogram (EEG) and therefore, of effective stunning. The results of univariate analysis showed that only slaughter method had highly significant effects on the power contents in the 13–30 Hz and 2–30 Hz EEG frequency bands. Based on these results, it is recommended that a minimum of 200 mA average (400 mA peak) current per bird should be delivered using 200 Hz pulsed DC, with a mark:space ratio of 1:1, to achieve effective water bath stunning in 80% of broilers. Frequencies of above 200 Hz pulsed DC would presumably require average currents of greater than 200 mA. Electrical water bath stunning of broilers with 200 mA average current of 200 Hz resulted in cardiac arrest in six out of eight broilers that showed epileptiform activity. Two other broilers that had cardiac arrest showed no epileptiform EEGs indicative of effective stunning. Owing to the prevalence of cardiac arrest in conscious broilers, the use of pulsed DC for water bath stunning of broilers could be questioned on ethical and bird welfare grounds.

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.

Laboratory animals are frequently subjected to routine procedures, such as injections or the withdrawal of blood samples. Acute stress caused by such procedures is associated with physiological changes that can have a strong impact on experimental results. This study investigated the integrated effects of cage enrichment, social housing and handling on the acute stress response of animals subjected to routine experimental procedures. Female mice of two inbred strains (BALB/c and C57BL/6) were housed under either minimal husbandry conditions (MH: no cage enrichment, infrequent handling and a period of individual housing) or enriched husbandry conditions (EH: with cage enrichment, frequent handling and social housing at all times). One mouse in each cage was implanted with a radio-telemetry transmitter for measuring heart rate (HR) and body temperature (BT). The animals were subjected to intraperitoneal injections or short periods of restraint. In addition to telemetry measurements, thymus weight and tyrosine hydroxylase (TH) activity were assessed. It was found that individual housing under MH conditions, as compared with social housing under EH conditions, elevated both basal HR and BT, and significantly elevated the relative recovery time following routine experimental procedures. Thymus weight and TH activity suggested a long-term stress response under MH conditions following individual housing, although the influence of transmitter implantation and (repeated) acute stress remains to be investigated. The results emphasise that husbandry conditions should be taken into account when evaluating physiological measures after routine procedures.

In the present study, the effects of social environment on the welfare of farmed silver fox cubs were clarified. After weaning, cubs from silver fox litters were housed (1) singly, (2) in litters until the end of September and thereafter singly, or (3) in litters throughout their growing season. Separating the cubs at the onset of the species' natural dispersal time may not be strictly beneficial for the cubs because it may limit the animals' possibilities to fulfil their needs for social behaviour. However, the lower incidence of bite wounds in both the single housed cubs and the cubs from litters that were split in autumn showed some beneficial effects of separating the cubs. The cubs that were group housed in litters for the whole time were focussed on their own social system, were more averse to human presence and showed greater responses to acute stress than the cubs that were single housed for at least part of the time. However, the serum cortisol level following adrenocorticotropic hormone administration suggested that cubs that were group housed in litters were less stressed over the long-term compared with the cubs that were single housed for at least part of the time; the low incidence of stereotypic behaviour in the cubs raised in litters also supports this hypothesis. Accordingly, and despite some unsolved questions regarding interpretation of the hypothalamic-pituitary-adrenal axis activity, the results from this present study show that social contacts were important for the welfare of silver fox cubs, and suggest that farmed silver fox cubs could possibly be raised in litters without jeopardising their welfare or deteriorating their fur quality.

Chromosome substitution strains (also called consomic lines or strains) are strains in which a single, full-length chromosome from one inbred strain — the donor strain — has been transferred onto the genetic background of a second inbred strain — the host strain. Based on the results obtained from behavioural tests with the two parental strains, the minimum number of animals from each of the host and consomic strains that are required for a successful behavioural genetic analysis can be estimated. Correct application of statistical knowledge can lead to a further reduction in the number of animals used in behavioural genetic experiments using chromosome substitution strains.

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.

Environmental enrichment by increasing foraging behaviour and providing food item choice are widely practised and generally accepted as effective methods for reducing stereotypic behaviour in captive animals. In this study, the effectiveness of increasing foraging patch choice and food item choice on reducing motor stereotypy in two captive vicugna were examined. For the purposes of the study, first, browse was added to the vicugna's enclosure as an additional forage item and, second, the vicugna's normal feed was divided: half being provided in the indoor quarters and half in the outdoor yard. The results revealed that providing browse as an additional forage item increased the observed stereotypic behaviour; however, dividing the vicugna's feed, and therefore increasing forage patch choice, decreased stereotypy. This study was limited because of the small sample size and because the area in which the vicugna were performing stereotypic behaviour was partially visually obscured. However, this study has implications for animal welfare because it highlights the need to evaluate the suitability of foraging enrichment items, and suggests that more research into accommodating the adaptive foraging behaviour of this species in captivity may be necessary.

This paper describes a two-part study of small predators in New Zealand forests. First, during 12 days of live-trapping, 31 wild ship rats were captured, tagged and released: 9 were handled while anaesthetised using halothane and 22 were handled while conscious using gloves. There was a significant difference between the two groups of ship rats in live-recapture rate: 4 out of 9 rats that had been handled while anaesthetised were recaptured alive, compared with 0 of 22 that were handled while conscious. Second, during 12 days of removal-trapping, 23 ship rats were killed, of which 6 were tagged, including 4 of the 9 that had been previously handled while anaesthetised (2 of which had also been recaptured alive during the live-trapping) and 2 that had previously been handled while conscious. These observations have implications for the statistical estimation of population density from capture-mark-recapture data and for the development of protocols for minimising stress in captured animals, especially nocturnal species released from traps in daylight.

The aim of this article is to report on the expert opinion regarding the provision of environmental enrichment for pigs. A questionnaire was sent to 53 pig welfare scientists who were asked to specify which enrichment materials they considered sufficient to ensure pig welfare; 68% responded. 89% stated that providing a chain was not sufficient, while 84% stated that the provision of straw could be sufficient. ‘Sustained animal-material interactions’, ‘rootability’, ‘manipulability’ and ‘chewability’ were the main material properties referred to as being required for enriching pig pens. Areas of further research suggested by the respondents encompassed both fundamental and applied research, including preference tests and demand studies, deprivation studies and quantitative studies to determine cut-off points. A case is made for modelling the available knowledge to help close the gap between what is known in science and what is decided in society regarding animal welfare and environmental enrichment for pigs.