Michael C. Appleby's research while affiliated with The University of Edinburgh and other places

Publications (103)

Article
Food security and sustainability are paramount goals of global policy in the Twenty First Century. What are the contributions of applied ethology and animal welfare in delivering these major goals? Livestock plays a major role in food security and nutrition (FSN), because meat and animal products are important in people’s diets and the livestock se...
Article
Furnished cages for laying hens have advantages in allowing normal behaviors and maintaining productivity. As the cost of introduction is a barrier for farms, we developed furnished cages that re-use conventional cages. To determine the minimum and functional cage design, we compared six designs, combinations of two floor designs (artificial turf o...
Article
Procedures that increase the sustainability of agriculture often result in animals being treated more humanely:both livestock in animal and mixed farming and wildlife in arable farming. Equally, procedures ensuring humane treatment of farm animals often increase sustainability, for example in disease control and manure management. This overlap betw...
Article
Theoretical models are presented of the effects of space, facilities and group size on the behaviour of chickens at high stocking densities, with relevance for all animals. The appropriateness of each model is supported by published data, although such data are scant for some important variables. Freedom of movement is analysed by taking the area o...
Article
Science has been invaluable for increasing understanding of animal welfare and as a result we know of many ways in which animal treatment and housing can be improved. However, implementation is slow because of political and economic considerations. This is particularly clear for farm animals. This raises the question of what else is needed, besides...
Article
Farm animal welfare has now been studied, within a scientific framework, for several decades. The framework does not include ethical issues, but unless measurements of animal welfare at farm level are embedded in an ethical context, there is a danger that these measurements will not be properly utilised. This paper considers the relationship betwee...
Article
This paper is the report of a meetingthat gathered many of the UK's most senioranimal scientists with representatives of thefarming industry, consumer groups, animalwelfare groups, and environmentalists. Therewas strong consensus that the current economicstructure of agriculture cannot adequatelyaddress major issues of concern to society:farm incom...
Article
Twelve Isa Brown hens (Gallus gallus domesticus) were trained to open a locked door for access to a pen containing an enclosed nest box ('nest test') and to return to a home pen containing food, water, litter and a perch ('home test'). The door was connected to a computer-controlled load cell, which recorded work exerted on the door and unlocked th...
Article
Since the publication of Animal Machines (Harrison, 1964), there has been widespread public pressure in Europe--supported by European institutions--to "ban the battery cage." The European Union (EU) and national governments (particularly in Northern Europe) funded research on noncage systems for egg production and enriched cages. In 1986, the EU pa...
Article
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...
Article
1. A 3-year trial was carried out of cages for laying hens, occupying a full laying house. The main cage designs used were 5000 cm2 in area, 50 cm high at the rear and furnished with nests and perches. F cages had a front rollaway nest at the side, lined with artificial turf. FD cages also had a dust bath containing sand over the nest. H cages had...
Article
This experiment investigated the ability of the domestic hen to predict a time interval of several minutes when given a reliable signal. This was achieved using the peak procedure method, an extension of a fixed interval (FI) schedule that gives partial reinforcement to identify temporal expectation on both sides of a remembered time for food deliv...
Article
Dairy calves are commonly vocal after separation from the cow and during the following weeks while they are fed milk. This study examined the functional and motivational basis for such vocalizations. In one experiment, we found that 14 newborn calves called on average (±S.E.M.) 31.4 (±7.0) times per day when fed according to conventional management...
Article
Weight gain, milk intake, starter intake and number of days with diarrhoea were measured for individually housed Holstein calves offered milk twice daily by bucket at 5% of body weight per feeding (n=11) or ad libitum from a teat (n=12) from birth until 4 weeks of age. Mean weight gains during the first 2 weeks were 0.36 and 0.85kg/day and during t...
Article
An important topic in the study of social behaviour of animals living in social groups is the description, analysis and explanation of dominance behaviour and relationships. Important questions in this context are (1) whether there are behaviours performed by the animals from which the existence of dyadic dominance relationships can be concluded, a...
Article
Stewardship is potentially a usefulconcept in modernizing management philosophies. Use ofthe term has increased markedly in recent years, yetthe term is used loosely and rarely defined in landmanagement literature. The connections between thispractical usage and the ethical basis of stewardshipare currently poorly developed. The followingdefinition...
Article
Vocalizations during competition among nursing piglets were studied to investigate their possible effects, functions and implications for welfare. In Expt 1, two experimental piglets in each of 14 litters were temporarily deprived of milk by covering their preferred teats on the sow’s udder. These piglets spent more time away from their teats than...
Article
Methods of ranking individuals in a dominance hierarchy that use transitivity of relationships may obscure irregularities. Furthermore, these methods use only a small proportion of the information available from dominance encounters. This paper presents an intuitively appealing and easily implemented alternative to existing methods for ordering dom...
Article
Two experiments examined the effect of age and diet on behavioural responses of piglets to separation from the sow. In Experiment 1, the vocalizations of piglets were recorded during short term (10 min) isolation from the sow and litter-mates at 1, 2, 3 and 4 weeks of age. From each of 10 litters, two piglets were assigned to each of the four age g...
Article
Attitudes to animal biotechnology are diverse, partly because people have different viewpoints and often do not recognize or acknowledge this to be so. First, people adopt different ethical approaches. If an opponent of genetic manipulation says 'I don't like the idea of altering animals' biology' and a proponent replies '...but it is useful', they...
Article
Full-text available
Although they have many disadvantages for welfare, including for behavior, laying hen cages also have advantages. For example, aggression and cannibalism (or the need for beak trimming to prevent these) are usually less than in other systems, benefiting both the birds and the producer. There have been three approaches to reducing other behavioral p...
Article
1. Three experiments were carried out with ISA Brown laying hens housed in individual cages with softwood perches of rectangular cross section fitted across the width of each cage, to investigate factors affecting the tendency of hens to lay their eggs from the perches and to use perches at other times. These factors were perch width and angle and...
Article
Full-text available
Modified laying cages are being developed in a number of European countries in response to public and legal pressure for improvement of laying hen welfare. The Edinburgh Modified Cage (which has a perch, nest box, and dust bath) is one design which is practical for commercial production. The trial reported here was concerned with specifications inc...
Article
Comments on the implications of genetic engineering for animal welfare. Welfare problems associated with techniques used to achieve genetic changes; Detrimental effects of genetic modifications to welfare; Modification of farm animals for biomedical products. Implications of genetic engineering for animal welfare are changing rapidly and need to be...
Article
The aims of this study were to investigate the effects of social interactions on access to the nest site and pre-laying behaviour of hens in small groups. Nine groups of four hens were placed in a littered round pen. Aggressive pecks, together with the identity of the individuals involved, were recorded for 8 h of the day. Behaviour in the hour pri...
Article
Laying hens,Gallus gallus domesticusshow individual variation in pre-laying behaviour including their ultimate choice of nest site. In housing systems with nestboxes, the majority of hens make a small number of long visits to nestboxes and lay their eggs therein, but some hens make many short visits and occasionally lay outside the nestbox. We inve...
Article
While considerable research has been undertaken on the hormonal basis of pre-laying behaviour of domestic hens (Gallus gallus domesticus), less is known about how the behaviour is initiated and about how changes in this behaviour occur. Two experiments were conducted to investigate aspects of the interaction of pre-laying behaviour with feeding mot...
Article
Full-text available
The present study was designed to examine effects of selection for milk production on the grazing behaviour of dairy cattle. Subjects were 43 Holstein Friesian cows from the LanghilI Dairy Herd in Edinburgh which consists of two genetic lines: one selected for high milk solids yield and a control line of average genetic index for milk solids yield....
Article
While much is known about the hormonal basis of pre-laying behaviour of domestic hens, Gallus gallus domesticuslittle is known about how the behaviour is initiated or how changes in this behaviour occur. An experiment was conducted in which hens had to overcome an aversive task, during the course of pre-laying behaviour, in order to reach a nest si...
Article
Many or most stimuli in the environment are variable. Sometimes animals will categorize this variation, and we tend to underestimate the complexity of the mechanisms involved. Probably more often, response to variable stimuli is itself variable. Examples are explored in four areas, including the possibility that stimuli may occur in supernormal for...
Article
In September 1994 a meeting was held in Edinburgh, UK, on the welfare of extensively farmed animals and this paper is an overview of that meeting including summaries of the discussions, workshops and conclusions. First the general principles involved were considered, and then the practice in two contrasting areas: the European Community and New Zea...
Article
Because of the evidence that growth hormone gene transfer in pigs and mice can result in widespread pathological changes and more general concerns that transgenesis techniques themselves may have deleterious effects, a study was undertaken to compare the behaviour of two populations of immature female sheep, one of transgenic and one of control ani...
Article
1. In 2 trials the health and behaviour of a total of 3552 caged laying hens of 4 hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in trial 1 and ISA Brown and LSL in trial 2, were studied. The cage designs were Get‐away cages (GA) with 15 hens per cage, a special version of the ‘Edinburgh modified cage’ called ‘Modified and enrich...
Article
Most studies of farm animal welfare have been carried out in intensive conditions. Considering the welfare of extensively farmed animals therefore raises questions of perceptions, processes and priorities. There are general perceptions that we are not responsible for the welfare of wild animals and that extensive conditions are good for welfare com...
Article
Persistence of searching behaviour during the pre-laying period in the presence of a suitable nest site may indicate that hens are strongly motivated to perform this behaviour. This was investigated by observing behaviour in environments with or without a suitable nest site and other cues for exploration. Eleven hens were tested individually in fou...
Article
1. Floor eggs are a problem in non-cage systems for laying hens, as they require secondary egg collecting. Failure to lay in a well-defined nest site may also be a welfare problem for the hens, but only if their nesting motivation has been thwarted. We investigated the relationships between a hen's prelaying behaviour and its tendency to lay on the...
Article
Domestic hens (Gallus gallus domesticus) from commercial laying strains have been selected for high egg yield and may lay over 300 eggs in their working lives. In conventional wire cages, there is little opportunity to perform either nest seeking or nest building activities, which may lead to frustration each time an egg is laid. To measure the dem...
Article
1. Behaviour, production and welfare of ISA Brown medium hybrids were assessed in 2 trials (each from 20 to 44 weeks of age) of a novel design of cage for laying hens: the Edinburgh Modified Cage (EMC). 2. The EMC was 600 mm wide, 450 mm deep and 450 mm high at the rear; it had a softwood perch and at one side a 250 mm wide nest box (containing lit...
Article
In two trials, production, feed consumption, mortality, egg quality and birds' live weight of a total of 2877 caged laying hens of four hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in Trial 1 and ISA Brown and LSL in Trial 2, were studied during full production cycles. The cage designs were Get-away cages (GA) with 15 hens per...
Article
This study was designed to examine the effects of relatedness on the behaviour, especially suckling behaviour, of twin beef calves. The subjects were 20 twin calves and their 10 dams. Eight of the 10 dams were mothers of twins consisting of one calf which was conceived by artificial insemination (AI) and one calf which was induced by embryo transfe...
Article
The apparent reluctance of many free-range laying hens (Gallus gallus domesticus) to disperse in the available outdoor area may be due, in part, to the large discrepancy between the indoor and outdoor environments. The objective of this study was to alter the novelty of an outdoor paddock by the introduction of familiar feeders, and examine hens' s...
Article
The effects of regular handling and/or exposure to the outside environment on immature laying hens' (Gallus gallus domesticus) fear levels and subsequent readiness to disperse in an outdoor area were investigated. When they were between 12 and 20 weeks old, 56 birds were subjected to one of three treatments: (1) no handling plus no outdoor experien...
Article
The possibility that laying hens,Gallus gallus domesticus, limit their movements in order to minimize the number of high-ranking or unfamiliar birds encountered was investigated. Two experiments measured the time taken by individual birds to move past other birds in order to reach a preferred area. Birds were trained to move out of a small, empty c...
Article
1. ISA Brown hens were housed as groups of 4 from 18 to 72 weeks in 24 cages 450 mm deep, each with a softwood perch of rectangular cross-section fitted across the rear. There were 4 treatments, each with 6 cages: cage widths and perch lengths were 480, 520, 560 or 600 mm. 2. Daytime perching did not differ significantly between the treatments. At...
Article
There is some controversy as to whether animals can be deprived of resources that they have never experienced. Will domestic hens (Gallus gallus domesticus), for example, that have been housed in conventional wire cages, be as motivated to use well-defined, littered nests as hens with prior experience of nests? This was tested by varying the qualit...
Article
Full-text available
This article supplements the published Proceedings of the 4th European Symposium on Poultry Welfare. It presents an overview of the conclusions of the Symposium and of the workshops and plenary discussions of the papers. The four main topics reviewed were: Basic Biology and Welfare, Welfare Criteria in Alternative Systems, Welfare of Turkeys, Water...
Article
1. Laying hens (192 ISA Brown medium hybrids) were housed from 18 to 72 weeks as groups of 4 in conventional or experimental cages. The main area of all cages provided 675 cm2/hen. All experimental cages had perches, dust baths and nest boxes, which were of three types: litter (L), artificial turf (A) or plastic rollaway (P). These facilities provi...
Article
Trabecular bone remodelling is known to be affected by loading or exercise, and thus exercise may effect the trabecular bone loss associated with osteopenia in laying hens. Sixteen ISA Brown hens were housed from 18 to 72 weeks old in cages with perches and 16 in similar cages without perches to examine the effects of the exercise afforded by perch...
Article
Fractures in spent laying hens are now recognised as a major welfare problem; the objective of this work was to determine whether provision of perches for caged layers would increase bone strength, bone volume or both. Sixteen ISA Brown hens were housed from 18 to 72 weeks old in cages with perches and 16 in similar cages without perches. At the en...
Article
1. Medium hybrid hens were housed as groups of 4 at 18 weeks of age in cages of 4 different types: control battery cages allowing 675 cm2/bird; similar cages with a rear‐mounted dust bath, 290×345×240 mm, containing sand (D); cages with a rear‐mounted nest box of the same size, containing wood shavings (N); cages with both (DN). In half the experim...
Article
At the 25th Anniversary Congress of the Society for Veterinary Ethology (now the International Society for Applied Ethology), six workshops were held on the future of applied ethology. Each was asked to identify important issues and to make recommendations on how those issues should be addressed. The topics of the workshops were: socioeconomics; ge...
Article
1. ISA Brown hens were housed, from 18 to 71 weeks of age, as groups of 4 in cages with 675 cm2/bird. There were 7 treatments: control cages and 6 treatments with perches fitted across the rear of the cage. Five treatments had 450 mm wide cages, with perches made from hardwood, textured metal, smooth plastic, softwood and padded vinyl, and one trea...
Article
1. ISA Brown hens were caged in groups of 4 from 20 to 72 weeks at 675 cm/bird. A control treatment in conventional cages was compared with 4 treatments involving softwood perches. In deep cages they were located across the front, across the rear and across both; in wide, shallow cages there was one long perch across the front. For half of each tre...
Article
1. ISA Brown hens were housed in groups of 4 in cages with different designs of nest boxes provided, to determine the effects of nest box design and management on their use and on the pre‐laying behaviour shown by the birds.2. There were 5 treatments: control (C); a wire‐floored nest box attached to the back of the cage (W); a nest box containing a...
Article
There are many different characteristics of housing systems which affect the welfare of laying hens, particularly because welfare itself has many diverse aspects. When cause and effect relationships between systems and welfare are assessed, it is evident that no system currently under consideration is ideal. Of those priorities listed by UK authori...
Article
In a trial of cage designs for laying hens, eggs were discovered in dust baths where access was restricted by a closed door during the normal laying period (08:00–13:00 h). Observations showed that the hens in these dust bath treatments had developed methods of opening the doors in order to lay in the baths. Three different methods of opening were...
Article
1. Behavior of ISA Brown hens was compared in cages with and without nest sites provided, to determine the characteristics necessary for such nest sites and whether part of the existing cage area could be modified to form an acceptable nest file. 2. There were 5 treatments: control (C); a wooden surround in one rear corner of the cage (S); a fiberg...
Article
Preliminary results are given from studies of cage-housed birds provided with various combinations of nest sites (of various designs), perches (placed at the front or back of the cages) and dust bath boxes. Tibial bone strength in end-of-lay hens was found to be markedly greater where perches were provided – suggesting a clear benefit from this add...
Article
Enforced proximity of cows while feeding has implications both for production and welfare. To measure the preferred separation of dairy cows during feeding, a group of lactating Friesian-Holstein cows was observed in a cubicle house. A complete diet was offered ad libitum in a food trough. The trough was reached through a feed rail which was divide...
Article
1. Flocks of medium hybrid laying hens were housed in a modified deep litter system; the house was divided into 2, 3 and 4 pens in three successive years. Flock size was 300 or 370 and stocking density varied from 3.4 to 10.7 birds/m2. Higher densities used were above those recommended by the Ministry of Agriculture, Fisheries and Food (MAFF). 2. A...
Article
In a study of individual variation in the behaviour of tethered sows, records were made of 76 Large White × Landrace sows in their first pregnancy (gilts) tethered in stalls. Scan sampling was carried out from 07.00 to 17.00 h on 2-3 consecutive days every 5 weeks, producing sample sizes at three stages of the pregnancy (Periods 1, 2 and 3) of 48,...
Article
The strength of the tibia was compared in 72-week-old ISA brown hens housed as groups of four for 52 weeks either in conventional cages or in cages with a 450 mm long perch, positioned either at the front or the back of the cage. The breaking strength of the bone was measured by subjecting it to a gradually increasing force on a three-point rig unt...
Article
Operant conditioning was used to measure the effect on the feeding motivation (hunger) of pigs of diluting nutrient restricted food allowances with straw. Twelve Large White × Landrace boars were maintained in individual pens where they received their daily food allowance. Prior to the experiment, the boars were conditioned in separate rooms to pre...
Article
1. Medium hybrid hens were housed from 20 to 64 weeks in a deep litter house as flocks of 300, 370 and 370 and at stocking densities of 2–4 to 10–7 birds/m in three successive laying cycles. Sister birds were housed in cages in an adjacent building as groups of 3 and 4, at 750 or 560 cm/bird.2. Hen housed egg production was lower on litter (208 to...
Article
The influence of the behaviour of neighbours on the development and performance of stereotypies was examined in Large WhitexLandrace sows tethered during pregnancy in a house with 88 stalls. Results suggested that behaviour of neighbours was not just being copied, but itself produced stress, and that the noise of chain chewing and manipulation was...
Article
Groups of 8 piglets were housed in flat-deck cages with slatted floors. Experimental cages were provided with a trough of sterilized earth, and the behaviour of focal individuals was recorded for comparison with controls. This replaced an earlier study, with which some of the results were combined. Records were analysed for frequencies and duration...
Article
Operant conditioning techniques were used to measure the feeding motivation (hunger) of pigs restricted to the low food levels used under certain commercial conditions. Six Large White × Landrace boars were maintained in individual pens where they received their daily food allowance. Initially food was available ad libitum ; subsequently boars were...
Article
1. Preferences of hens for different types of nest box were tested in two deep litter pens, each containing 300 Isabrown laying hens. Four types were offered: traditional wooden nests with litter, metal rollaway nests with plastic liners, wooden rollaway nests with artificial turf and autonests.2. Most eggs were laid in traditional nests (70% in pe...
Article
1. The effect of perching experience on use of ground level nest boxes was tested in medium hybrid hens. Twelve out of 14 hens (86%) reared without perches laid their first egg on the floor when isolated with ground level nests. Only 4 out of 19 hens (21%) reared with perches laid on the floor. Medium hybrids with experience of only one level appar...
Article
Full-text available
1. Normal adult laying hens, which produced 41 g egg/hen d, ate 30 g/hen d more of a pelleted diet than did hens of the same age which were induced to lay eggs internally by surgical treatment of their oviducts. This implied that 0.336 MJ metabolised energy was required to produce 0.251 MJ egg, or 75% efficiency of utilisation of ME. 2. This may no...
Article
The behaviour of Large White × Landrace gilts tethered in stalls was studied by scan sampling from 07.00 to 17.00 h on 3 days consecutively every 5 weeks. Results are presented on 30 gilts sampled during their first 5 weeks in the house, period 1, and on 36 gilts during the following 5-week period, period 2. Twenty individuals were common to both s...
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Full-text available
INTRODUCTION Although domestic hens have been subject to artificial selection for centuries (Wood-Gush, 1959), they retain a behavioral repertoire comparable to that of their probable wild ancestors and of other galliform species (Duncan, 1980). An understanding of behavior is important in management, both for the efficient utilization of beneficia...
Article
Following reports of inconsistent nest choice by hens in groups, choice of nest boxes by solitary hens was investigated. Thirty-two hens of a White Leghorn strain were each isolated with six nest boxes while they laid six eggs. From 16 hens, eggs were collected daily. Only one of these birds laid all her eggs in one nest box, and others used up to...
Article
1. The nesting behaviour of broiler breeders was studied in a commercial flock of nearly 4000 birds kept on deep litter by tagging a sample of 200 hens. Use of nest boxes by tagged birds was recorded on 52 d over 34 weeks.2. Forty hens were never observed in nest boxes and 33 others were recorded only in ground‐level boxes. These 73 birds were reco...
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Full-text available
Movements of broiler breeders were studied in commercial flocks of nearly 4000 birds kept on deep litter by tagging samples of individuals. In Flock 1, locations of females in the house were recorded on 52 days over 34 weeks. Individual ranges analyzed were all more than half the area of the house, with a median of 505 m2 (73% of the area). Most or...
Article
The involvement of light in nest-site selection by domestic fowls was tested in two strains of laying hens at two stages of maturity. Individuals that were about to lay an egg were isolated in a pen and given a choice of two sorts of nest-box, one illuminated internally and the other without illumination. Nearly all birds tested laid in one of the...
Article
1. To test the preferences of hens for particular social conditions when laying, they were provided with choices of nest‐sites varying in seclusion. Three experimental conditions were used.2. In Experiment 1, nest‐site selection by members of a group of light hybrids was studied in a complex pen‐system. Eggs were clumped in distribution ; only one...
Article
Patterns of association and interaction in a free-living group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, were examined for factors affecting individual involvement in competition. Association was more clearly related to social rank, which depends on competitive ability, than to age or genetic relatedness. In fact, there wa...
Article
A method for identifying eggs laid by different subsections or individual members of groups of domestic hens is described. Fat-soluble dyes are placed in gelatin capsules and fed to selected birds. These dyes produce discrete colored bands in the yolks of eggs laid by those birds. The presence of dye in eggs can be detected through the shell, and d...
Article
The common practice of ranking a group of animals in the closest possible order to a linear dominance hierarchy assumes that dominance among those animals is generally transitive. In fact, analysis of groups in which dominance relationships are random shows that this method has a surprisingly high probability of producing an apparently linear or ne...

Citations

... Food security and sustainability are paramount goals of global policy in the Twenty-First Century; which are inextricably linked in the analysis of animal production (Appleby & Mitchell, 2018). Animal welfare is a crucial element for the sustainability of the agri-food industry and is a term used to express ethical concerns about the quality of life experienced by animals, particularly those used by human beings to produce meat (Hansen & Østerås, 2019). ...
... The duration of TI reaction, that was, the freeze until righting Table 1. Behavioral categories and descriptions (Meng, Chen, Xiang, Li, and Bao, 2016;Shimmura, Maekawa, Hirahara, Tanaka, and Appleby, 2017). ...
... The most important way of minimizing such problems is to keep the animals in stable groups since social mixing leads to much fighting with consequent injuries, bruising and extreme physiological responses (Kenny and Tarrant 1982). In stable groups, mounting may lead to more injury than does fighting (Appleby andWood-Gush 1986, Mohan Raj et al 1991). Animals that are frequently mounted become bruised and may suffer severe leg injuries. ...
Reference: Welfare
... More 'natural' costs such as squeezing through a narrow gap [43], or pushing through a weighted door [9,10] or walking a long way [44] overcome this difficulty and also have the advantage that they require little or no learning [43]. In the present experiment we chose to use the natural cost of walking through water, which hens find aversive [45][46][47]. Water also has the advantage that the cost can be varied by increasing the length and depth of the water. ...
... Aviaries come in many configurations and offer features such as open litter areas, multiple vertical tiers, perches, and nests. In addition to offering more floor space per bird than traditional caged housing, the added features of an aviary are meant to facilitate natural, strongly motivated behaviors in hens including dust bathing (Vestergaard, 1982), roosting (Brendler and Schrader, 2016), perching (Appleby and Duncan, 1989;Newberry et al., 2001), and laying eggs in a nest (Cooper and Appleby, 1995). Facilitating performance of these behaviors is intended to increase hens' welfare while in production (Lay et al., 2011). ...
... High stocking density negatively impacts body weight, feed intake, and mortality for hens raised in conventional cage systems (Carey, 1987;Widowski et al., 2013). Past studies evaluating ECC housing systems have compared measures on hens housed in ECC system to hens housed in other housing such as conventional cage, cage-free, and free-range systems (Appleby et al., 1993(Appleby et al., , 2002Abrahamsson and Tauson, 1997;Appleby, 1998;Tactacan et al., 2009;Blatchford et al., 2016;Gast et al., 2016). Furthermore, studies evaluating stocking density in ECC systems have also included vertical space, group size, and cage size factors (Weitzenbürger et al., 2005;Albentosa et al., 2007;Widowski et al., 2017a,b). ...
... The way fast-growing broilers make use of space in intensive housing has been of interest for some time, with researchers debating whether chickens in large flocks create home ranges or use the space randomly (McBride and Foenander, 1962;Appleby et al., 1985). However, the methods available for accurately tracking small animals indoors have been extremely limited. ...
... European countries, expressed their concern about the extremely restricted space allowance and the lack of nests, perches and litter (Blokhuis et al., 2007). Fear has been assumed as influencing factor of the decision of hens to use or to avoid access to free range (Grigor et al., 1995). This has been confirmed in a study of Hartcher et al. (2016). ...