This paper reviews the impact on fish welfare of a wide range of slaughter methods used commercially around the world. Because the end result of the slaughter is a food product, and because of the well-known relationship between an animal's welfare and subsequent meat quality, the effects of the slaughter methods on the quality of the flesh are also reviewed where possible. Fish slaughter methods are incredibly diverse, but fall into two broad categories: those that induce loss of sensibility slowly, and those that achieve this rapidly. This paper shows that, in general, the methods that induce loss of sensibility over a long period of time tend to impinge more on the welfare of the animal and are detrimental to the overall quality of the carcass. Methods that cause a rapid loss of sensibility result in the best welfare, providing that they are carried out correctly. They may also produce the highest quality product from the stock offish.

There has been much consideration of well-being in philosophy, especially of human well-being, which contributes to our understanding of animal welfare. Three common approaches to well-being are presented here, which map approximately onto three possible ideas about animal welfare. Perfectionism and other forms of ‘objective list’ theories suggest that there are various values that should be realised or various things that an individual ought to have for his life to be a good life. In the case of humans, this is based on the concept of human nature. This approach is reflected in two ideas about animal welfare: first, that animals should live natural lives (which includes consideration of an animal's nature or ‘telos’), and second, that welfare is concerned with functioning or fitness of animals. The two other approaches are subjective: in other words, they relate solely to the mental processes of the subject. The first, desire fulfilment, suggests that well-being is defined by the satisfaction of desires or preferences. The other, hedonism, states that well-being is the presence of pleasant mental states and the absence of unpleasant ones. These two approaches are both relevant to the idea that the welfare of animals relates solely to their feelings. That idea corresponds most closely to hedonism, so it may be that preferences are most relevant in helping to reveal feelings. However, it is sometimes implied that satisfaction of preferences is itself part of feelings. It would also be possible to maintain, as in the desire fulfilment approach to human well-being, that animal welfare consists of preference satisfaction itself. These possibilities need to be more clearly distinguished. Arguments for and against each approach to well-being are presented, so that scientists may be more aware of the strengths and weaknesses of their own ideas about animal welfare.

The objective of the present study was to investigate the relationship between rooting behaviour and foraging in growing pigs. In study 1, forty-eight 11-week-old pigs were housed in eight groups of six with access to a rooting substrate in the form of spent mushroom compost. In half of the groups the rooting substrate contained food rewards, and in the other half of the groups it did not. All pigs had ad libitum access to feed. In study 2, one hundred and ninety-two 11-week-old pigs were housed in thirty-two groups of six, all with access to spent mushroom compost, and eight groups were each fed to 70, 80, 90 or 100% appetite. Treatments were applied over a two-week period in both studies. The number of pigs involved in active rooting (rooting in substrate while standing), inactive rooting (rooting in substrate while sitting or lying) or non-rooting activity (standing in substrate area and involved in any activity except rooting) was recorded by scan sampling. These behaviours tended to reach a peak in the morning and again in the afternoon. Inactive rooting was not significantly affected by treatments in study 1 or study 2. Food rewards in the rooting substrate led to a significant reduction in active rooting behaviour and in non-rooting activity during peak periods of the day (P < 0.05). It is suggested that learned associations between rooting behaviour and acquisition of food caused the pigs to stop rooting when all the food rewards had been consumed. The fact that rooting was performed in the absence of nutritive feedback suggests that this behaviour is performed independently of its appetitive foraging function. Restricting feed levels to 70 or 80% of appetite led to a significant increase in active rooting and in non-rooting activity during peak periods (P < 0.05). The relationship between feed restriction and active rooting behaviour tended to be linear (P < 0.08). This suggests that levels of rooting behaviour are flexible in response to nutritional needs.

Some physiological variables which could aid in assessing the welfare of beef cattle in feedlots were screened in this exploratory study. In two experiments, each of 42 days duration, the physiological responses of Bos taurus steers to three treatments were investigated: pasture (rotation between 1.5 hectare paddocks); a feedlot yard stocked at 12.0 m2 per head with a dry, firm pen surface; and a ‘high-density’ feedlot yard stocked at 6.0 m2 per head with a wet and muddy pen surface. Fourteen steers were used per group per experiment. Relative adrenal mass in both feedlot groups was 8-10% higher than in the pasture group, and this finding was supported by morphological measurements of the adrenal glands. Out of 17 immune variables examined, only serum IgA and the T-cell lymphocytes subpopulation WC+1 showed consistent differences between the feedlot and pasture groups. Interestingly, no differences were observed between the two feedlot treatments. It was concluded that although there may have been some disruption of epithelial/mucosal immunity, more support was required from other immune variables before it could be stated that the immune system was depressed and that pre-pathological states existed in the feedlot groups. However, measures of relative adrenal weight, adrenal index, serum IgA and WC1+ lymphocytes are good candidates for use in future welfare investigations of feedlot cattle.

Animal rescue shelters provide temporary housing for thousands of stray and abandoned dogs every year. Many of these animals fail to find new homes and are forced to spend long periods of time in kennels. This study examined the influence of the length of time spent in a rescue shelter (<1 month, 2-12 months, 1-5 years, >5 years) on the behaviour of 97 dogs. The dogs ‘ position in their kennels (front, back), their activity (moving, standing, sitting, resting, sleeping), and their vocalisation (barking, quiet, other) were recorded over a 4 h period at 10 min intervals. The dogs’ behaviour was significantly related to the length of time the animals had spent in the rescue shelter. Dogs housed in the shelter for over five years spent more of their time at the back of their kennels, more time resting, and less time barking than dogs housed in the shelter for shorter periods of time. The age of the dog could not account for the significant results found, suggesting that environmental factors were responsible for the change in the dogs’ behaviour. The findings suggest that lengthy periods of time spent in a captive environment may encourage dogs to behave in a manner that is generally considered unattractive by potential buyers. This may decrease the chances of such dogs being adopted, resulting in longer periods of time spent in the kennel environment and the possible development of further undesirable behaviours.

There is some evidence that rats benefit from social housing and from some forms of environmental enrichment, such as platforms and shelters. It is less clear whether they benefit from more spacious cages. There is a lack of information about the relative benefits of social contact, enrichment and increased space, because existing studies tend to concentrate on only one of these variables at a time. The current experiment used economic demand procedures as a method to compare, on a single scale, qualitatively different environments with a standard home cage. The data indicate that rats show a high demand for social contact, and a low demand for a larger cage or one containing pillars or novel objects. This finding suggests that social housing of laboratory rats should be strongly advocated.

The return to consciousness of 24 electrically stunned lambs was assessed by measurement of physiological reflexes and electroencephalography (EEG) recordings. The physical activity of the lambs after head-only electrical stunning included one tonic phase and two clonic phases. The tonic phase began immediately after the stun and ended 10 s after the stun; the first clonic phase started immediately after the tonic phase and ended 36 s after the stun, and the second clonic phase started immediately after the first clonic phase and ended 70 s after the stun. During the tonic phase and the first clonic phase, electrical activity recordings of the brain showed a dramatic increase in the relative power spectra of alpha and beta frequencies. Both frequencies returned to pre-stun levels with the end of the first clonic phase. During the second clonic phase, the relative power spectrum of theta frequency was higher than that before stunning. These results suggest that during the tonic phase and the first clonic phase, the animal was unconscious, whereas during the second clonic phase the return of some conscious function began. Spontaneous breathing returned at about 29 s post-stun, whereas the corneal reflex returned at about 38 s. It is therefore suggested that the return of spontaneous breathing is the safest indicator that the animal is close to recovering consciousness.

Reversible contraceptives, such as melengestrol acetate (MGA) implants, have become an invaluable tool that captive-animal managers use to maintain various species in social groupings while avoiding unwanted pregnancies. The American Zoo and Aquarium Contraception Advisory Group (AZA CAG) monitors the efficacy, reversibility, and safety of contraceptives used in captive exotic mammals worldwide. Because so few data exist on contraceptive efficacy and safety in exotic species, it is critical that evaluations reflect an understanding of the mechanism of action of the active ingredient as well as of the delivery system. The following discussion addresses the concerns of the CAG over the manner in which De Vleeschouwer et al (Animal Welfare 2000, 9: 251-271) analysed MGA implant reversibility data in golden-headed lion tamarins.