TWA limit c ppm
B. ANIMALS USED IN AGRICULTURAL RESEARCH 1. Introduction
The report of the Brambell Commission in 1965, described the farm animal's "Five Freedoms" as the ability to easily "turn around, groom itself, get up, lie down, and stretch its limbs" (Brambell, 1965). In 1989, the WVA adopted its own Five Freedoms, which applied to all species and which were based on those of Britain's Farm Animal Welfare Council (FAWC) (Webster, 1987). The FAWC has recently revised these Five Freedoms, which define ideal states and which now include:
a) Freedom from hunger and thirst;
b) Freedom from discomfort;
c) Freedom from pain, injury and disease;
d) Freedom to express normal behaviour;
e) Freedom from fear and distress (Seamer, 1993).
Carpenter (1980) suggested enough freedom to perform natural physical movement, including daily routines of natural activities; facilities for comfort activities such as rest, sleep, and body care; adequate food and water to maintain full health; social contact with other animals of their own kind; opportunity for exploration and play, especially in young animals; and satisfaction of minimal spatial and territorial
The necessary scientific knowledge upon which to base a comprehensive set of guidelines which would fully protect the welfare of agricultural animals is not yet available (Expert Committee on Farm Animal Welfare and Behaviour, 1987). Nonetheless, the CCAC believes that there is sufficient information to set out some general principles that can be updated and expanded as
Codes of Practice for Canada for pigs, veal calves, poultry, dairy cattle and beef cattle (Agriculture Canada, 1771/E, 1984; 1821/E, 1988; 1757/E, 1989; 1853/E, 1990; 1870/E, 1992) represent the basic industry standards and, for the most part, are the minimum CCAC requires for research institutions undertaking agricultural research. In addition, a revision of the Recommended Code of Practice for the Care and Handling of Farm Animals--Pigs (1898/E) is now in press. Researchers and others working with agricultural animals must be fully conversant with these codes.
The Health of Animals Act (Government of Canada, 1990), which replaced the Animal Disease and Protection Act, states that the "Governor-in-Council may make regulations:
a) for the humane treatment of animals and generally:
i) governing the care, handling and disposition of animals;
ii) governing the manner in which animals are transported within, into or out of Canada; and
iii) providing for the treatment or disposal of animals that are not cared for, handled or transported in a humane manner."
Curtis (1992) suggests that there is a double standard in place regarding current farm practices and the procedures used with agricultural animals in biomedical research. This is a dilemma not uncommonly faced by ACCs. Another dilemma occurs because agricultural animals are used in food and fibre-related research, as well as biomedical research, and it is often difficult to clearly label such studies as being only agricultural or only biomedical (Stricklin, Purcell and Mench, 1992).
In attempting to develop guidelines, thought, observation, and concern for the animal must be uppermost in our minds for, as Hurnik (1988) states: "There is a need to exercise extreme care to avoid the
emotional tendency to rely exclusively on characteristics which may be of concern to humans, but that are not necessarily central to the overall quality of animal life." Spedding (1988) also warns that "perhaps the biggest danger is that a dissatisfied public may demand changes that eliminate what is disliked, but result in either no improvement or even a reduction in the welfare of the animals involved."
In that we must "work to ensure the animal's welfare in life and at the point of death" (Webster, 1987), we might note a recent example of change resulting from human perception of what constitutes
humaneness, when Great Britain passed Slaughter of Animals (Humane Conditions) Regulations 1990 (effective July 5, 1992), requiring head restraint during slaughter of cattle. Unfortunately, after the fact, research showed, by measuring cortisol levels, that the restraint process was far more stressful than allowing the animal to stand free when the captive bolt was fired (Ewbank, Parker and Mason, 1992).
2. Animal Stress
Suffering, loosely defined as experiencing a wide range of unpleasant emotional states such as pain, fear, anxiety, frustration and perhaps boredom, can be a major threat to an animal's welfare. Poor animal welfare may be apparent in changes in an animal's behaviour, physiology, health status, reproduction or growth. Many clinical conditions in animals first become apparent to observers through a set of
behavioural indicators (Fraser, 1984/85). Depressed animals show a depletion of the behavioural repertoire characteristic of the normal animal (Fraser, 1984/85, 1988).
The three ways in which an animal responds to a stressful situation include changes in behaviour,
activation of the autonomic nervous system, and activation of the neuroendocrine system. Because of its rapid and specific responses to many stressors, the autonomic nervous system has been an appealing candidate for the diagnosis of stress by measuring heart rate, respiration, and the secretion of
catecholamines. Many investigators accept the increased secretion of glucocorticoids as proof of stress occurring. It has been demonstrated that stress associated with transportation, restraint or handling diminishes immune function in a number of livestock species (Grandin, 1992; Kelley, Osborne, Evermann et al. 1981; Coppinger, Minton, Reddy et al. 1990).
However, Moberg (1985) states that monitoring these autonomic nervous system and endocrine system responses outside the laboratory has not been practical, and thus they have proven to be of little use in defining stress and well-being in domestic animals. Duncan (1992) notes that sophisticated biological systems have evolved to help animals cope with stress, and that, while it is impossible for us to shield agricultural animals from all stress, the key to protecting their well-being is to minimize the biological costs of unavoidable stress, and to recognize the need for research directed at stress.
The idea that animals have certain "behavioural needs" has received considerable attention. For example, Baxter (1983) has argued that all psychological processes which affect animal welfare must have a
desired state or set point (or set band covering a range of values) at which the animal will strive to remain, or to which it wishes to return. Deviations from this set point will cause a reduction in the
animal's well-being. However, Hughes and Duncan (1988) reviewed the literature in this area and showed that, in certain cases, an argument could be made for animals needing to be able to perform particular behaviours, even if the goal of the behaviour has already been provided to the animal.
A behavioural need will appear in the cases of behaviour motivated mainly by internal factors or by a complex interaction between internal and external factors where the performance of the pattern is
constrained. For example, a hen provided with a replica of a nest is still motivated to perform normal nest building behaviours (Hughes, Duncan and Brown, 1989).
3. Housing and Husbandry
Three major factors influence welfare in animal agriculture: a) housing; b) stockmanship; and, c)
management (Hurnik, 1988). Hughes and Duncan (1988) suggest that, in order to fully protect welfare, a housing system would have to allow the performance of certain behaviour patterns in addition to
providing all the environmental needs of the animals. However, which behaviour patterns are essential has yet to be elucidated, and research is being undertaken to answer this question (e.g., Dawkins, 1990).
In the U.S., the American Association for the Accreditation of Laboratory Animal Care (AAALAC)(1991), takes the position that, in accredited facilities, housing and care for farm animals should meet the standards that prevail on a high quality, well-managed farm.
In maintaining farm animals in the laboratory, it is important to be aware of their behaviour in a farm situation. A prominent feature in farm animal behaviour is the active way in which individuals associate with each other and form social groups (Mench, Stricklin and Purcell, 1992; Fraser and Broom, 1990;
Grafen, 1990). Isolation from conspecifics is a profound source of stress (Grandin, 1992; Gross and Siegel, 1981), as social animals obtain both physical and physiologic comfort from each other (Friend and Dellmeier, 1988; Van Putten, 1988).
Proper handling and restraint of farm animals in a laboratory environment are key elements to their success as research animals. Prior familiarizing of experimental animals to handlers and experimental procedures can be of considerable benefit in the laboratory, says Panepinto (1992), the developer of the Panepinto sling used to restrain miniature swine and sheep. Stroking the pig, as opposed to stressing it, has been shown to have a beneficial effect on reproduction (Panepinto, 1992; Anon., 1992).
Animals raised in a barren, non-stimulating environment may display stereotypies such as bar biting, cribbing or tongue rolling in horses (Van Putten, 1988; Fraser and Broom, 1990; Fraser, 1992).
Environmental enrichment will often reduce unwanted excitability and help prevent abnormal behaviour (Grandin, 1992). For example, in housing domestic poultry used in experimentation, nest boxes and perches (high and low) should be provided. Aquatic fowl should have access to a swimming facility or some form of wetting in clean water.
Animals should be housed singly only when the experimental procedure requires this; e.g., in metabolism studies, some infectious disease studies or nutritional research.
When animals are introduced to each other and a group is established, there is an initial period during which the animals often fight in an effort to work out their social relationships (McGlone and Curtis, 1985;
Fraser and Rushen, 1987; Fraser and Broom, 1990; Mench, Stricklin and Purcell, 1992). Subsequently, dominance-subordinate relationships continue; however, interactions are subtle, based more on
avoidance or ritualized threat. Animals should be regrouped as infrequently as possible, so that they need not repeatedly endure the stabilization process (Fraser and Broom, 1990; Kenny and Tarrant, 1982).
In housing domestic species, Mench, Stricklin and Purcell (1992) suggest that there should be enough space for maintaining some minimum separation from each other, equal access to feed and water, and the ability to engage in significant behaviours and make normal postural adjustments. However, it has been demonstrated that when animals are group housed, the area available to a particular animal does not consist just of its individual space, but instead the entire area in which the animal is enclosed.
Therefore, the space requirements per animal are greater when one houses one or few individuals (Stricklin, Purcell and Mench, 1992).
The animal should also receive, on a regular and substantial basis, attention from an attendant trained to deal with the species (Kilgour and Dalton, 1984). It is noted that the domestication of various species has depended on their capacity for social affinity with humans (Gross and Siegel, 1982; Gonyou, 1991).
Substantial periods of observation must be maintained by the personnel responsible for the well-being of these animals (e.g., animal attendants, veterinarians) and adequate provision made in the work-time schedule to permit regular appraisal of the balance between social group and space.
A stockperson's quality will depend on his or her ethical sensitivity, familiarity with the animals, skill in interpreting behavioural symptoms indicating deprivation, suffering and morbidity, and the care shown in handling animals. The stockperson's skill in carrying out particular tasks such as castration, injecting animals, clipping teeth, etc., is also very important. Objective studies are now being carried out to identify the characteristics of good stockmen (Seabrook, 1984, 1987; Hemsworth, Barnett, Coleman et al. 1989). The quality of management refers to such things as decisions about operation of ventilation systems, provision of food and water, provision for emergencies, provision of sanitation and prophylactic measures, and choice of techniques and procedures for castration, dehorning, giving injections, etc.
The quality of a housing and husbandry system can affect welfare in many different ways. It can, of course, act in a direct physical way by causing injury, by reducing health, or by providing climatic conditions which are far from optimal. It may also reduce welfare by affecting the behaviour, or the physiological and immune systems of the animals.
Duncan (1981, 1983) has proposed the following classification for physical and social effects of husbandry systems.
a) Physical Effects
Aspects of the physical environment provided may reduce welfare by altering the animal's behaviour by:
1) blocking or frustrating the performance of a particular activity; 2) failing to provide the specific releasing stimuli necessary for eliciting certain behavioural patterns; and 3) providing too high a level of general stimulation. For example, if the environment is too complex or keeps changing in a way that the animals cannot predict, the animals may then become fearful and anxious. Alternatively, if the
environment is too barren and monotonous, the level of general stimulation may be too low, leading to boredom. While it is not easy to measure fear and boredom in a scientific way, we must not assume that animals do not experience these emotions.
b) Social Effects
Husbandry systems can also influence the behaviour and welfare of animals by altering and controlling the animals' social environment. All of the common agricultural species are gregarious, which means that an inadequate social environment can be expected to reduce welfare. Compared to what might be
considered as "normal" or "natural," many husbandry systems often deviate in the following ways: 1) the parent-offspring bond may be disrupted or prevented from forming; 2) young animals may be weaned too early; 3) animals may be kept in groups that are too large or small; 4) animals may be kept at too high a density; 5) animals may be kept in single-age or single-sex groups; 6) group membership may be disrupted; and 7) animals may be isolated to some extent.
4. General Principles
In order to improve and enhance the animal's environment, the CCAC encourages research institutions:
a) to experiment with group housing for such animals as lactating sows (after a few days in farrowing crates), calves, dairy cows and sheep. It is recognized that group housing may lead to increased
aggression or bullying among animals, increased chance of disease transmission, and increased difficulty in detecting health problems of individual animals. However, unless the welfare or safety of an animal is in danger, these facts should not be used to reject group housing. The level of animal management will probably have to increase and the training required for stockpersons will have to change. Evidence is accumulating that new piggeries should not have individual stalls for gestating gilts or sows unless
required for experimental purposes (Barnett, Winfield, Cronin et al. 1985; Barnett and Hemsworth, 1991;
Becker, Ford, Christenson et al. 1985; Cronin, Van Tartwijk, Van Der Hel et al. 1986; Schouten, Rushen and De Passillé, 1991; Von Borell and Ladewig, 1989).
b) to practise environmental enrichment such as providing toys for pigs, "teats" for veal calves, small orifice nipples and frequent feedings for artificially raised lambs, and greater opportunities for animals to perform normal food searching and foraging behaviours.
c) to provide the means for increased social contact and to allow the animals to perform a wider range of behaviours.
d) to increase the age at weaning. For example, piglets weaned at three weeks have an increased incidence of belly nosing (an abnormal behaviour); the recommended minimum age for weaning is therefore four weeks.
e) to shorten periods of isolation and restraint and to use them only when it is absolutely necessary, and not merely for the convenience of the experimenter. Individually penned animals should be allowed to maintain visual contact with at least one other animal while standing or lying in the pen, unless the isolation is required for experimental purposes and has been approved by the ACC. For pigs, in particular, maintaining olfactory contact may be as important as visual contact. In sheep, the head region is the
primary focal point used to recognize each other and should therefore be the least obstructed region from the perspective of neighbouring sheep trying to maintain visual contact.
The Expert Committee on Farm Animal Welfare and Behaviour (1987) suggests that government agencies and universities should re-order their priorities so that research on farm animal welfare and behaviour will have a level of staffing and support typical of that supplied to other disciplines such as nutrition,
reproductive physiology, genetics, and food products.
The CCAC recognizes the importance of education in improving animal well-being and welfare. Ideally, all students of animal production and veterinary medicine should receive instruction in farm animal
behaviour, animal welfare, and the ethics of livestock production.