JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, a... more JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK * Contact for c... more Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK * Contact for correspondence and requests for reprints: [email protected] ... Commercially reared broiler chickens are commonly supplied with drinking water through lines of nipple ...
ABSTRACTContaminated chicken meat is a major source of human Campylobacteriosis and rates of infe... more ABSTRACTContaminated chicken meat is a major source of human Campylobacteriosis and rates of infection remain high, despite efforts to limit the colonisation of broiler (meat) chicken flocks on farms. Using conventional testing methods of culture or qPCR, Campylobacter is typically detected amongst broiler flocks from 3 weeks of age, leading to the assumption that infection is introduced horizontally into chicken rearing houses at this time. In this study, we use parallel sequencing of a fragment of the Campylobacter outer membrane protein, encoded by the porA gene, to test for presence of Campylobacter DNA amongst fresh faecal samples collected from broiler flocks aged 23-28 days. Campylobacter DNA was detected in all of the 290 samples tested using the porA target, and in 48% of samples using 16S bacterial profiling, irrespective of whether or not Campylobacter could be detected using conventional qPCR thresholds. A single porAf2 variant was predominant amongst flocks that would b...
We formulate a mathematical model for daily activities of a cow (eating, lying down, and standing... more We formulate a mathematical model for daily activities of a cow (eating, lying down, and standing) in terms of a piecewise affine dynamical system. We analyze the properties of this bovine dynamical system representing the single animal and develop an exact integrative form as a discrete-time mapping. We then couple multiple cow "oscillators" together to study synchrony and cooperation in cattle herds. We comment on the relevant biology and discuss extensions of our model. With this abstract approach, we not only investigate equations with interesting dynamics but also develop interesting biological predictions. In particular, our model illustrates that it is possible for cows to synchronize less when the coupling is increased.
When definitions and explanations are provided for key points in science, students' understanding... more When definitions and explanations are provided for key points in science, students' understanding of the whole field is enhanced. Unravelling Animal Behavior does an excellent job of providing definitions and explanations for some important current research areas in ethology (adaptation, optimality, inclusive fitness, behavioral genetics, neurophysiology, communication, evolutionary stable strategies and sexual selection) and older areas that should die (instinct and fixed action pattern). Advantages: The writing is lucid, and summaries end each chapter. Very clear explanations are given for: how bats echolocate; the advantage of helping close kin; dynamics maintaining a 50:50 sex ratio; how particular environments support the expression of genetic traits; why "innate" and "learned" are not dichotomous. Disadvantages: Classical studies are reviewed without citation of recent studies that update or refute the original studies. Omissions include recent research on learning and consideration of group selection (p. 135). Some complex topics, such as evolutionary stable strategies, should be explained in more detail. Recent developments in molecular biology probably contradict some behavioral genetics conclusions. A few terms (allele, pleiotropy, variance) are undefined, and redundancy is high. More photographs and diagrams that explain points wouldI
Group level measures of welfare flocks have been criticized on the grounds that they give only av... more Group level measures of welfare flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that the group-level optical flow patterns made by broiler flocks can be used to deliver information not just about the flock averages but also about the proportion of individuals in different movement categories. Mean optical flow provides information about the average movement of the whole flock while the variance, skew and kurtosis quantify the variation between individuals. We correlated flock optical flow patterns with the behavior and welfare of a sample of 16 birds per flock in two runway tests and a water (latency-to-lie) test. In the runway tests, there was a positive correlation between the average time taken to complete the runway and the skew and kurtosis of optical flow on day 28 of flock life (on average slow individuals came from flocks with a high skew and kurtosis). In the water test, th...
Group level measures of welfare such as the optical flow patterns made by broiler chicken flocks ... more Group level measures of welfare such as the optical flow patterns made by broiler chicken flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that by using the skew and kurtosis in addition to the mean, optical flow patterns can be used to deliver information not just about the flock average but also about the proportion of individuals in different movement categories. We correlated flock optical flow patterns with the behaviour of a sample of 16 birds per flock in two runway tests and a water (latency-to-lie) test. In the runway tests, there was a positive correlation between the time taken to complete the runway and the skew and kurtosis of optical flow on day 28 of flock life (slow individuals came from flocks with a high skew and kurtosis). In the water test, there was a positive correlation between the length of time the birds remained standing and the mean and variance of flock op...
When shown familiar and unfamiliar birds at different distances, hens viewed birds 0.7 m or 1.4 m... more When shown familiar and unfamiliar birds at different distances, hens viewed birds 0.7 m or 1.4 m away with modal head angles between 54° and 72° from the midline, using the lateral visual field but viewed birds closer (less than 20 cm) binocularly, with the head within 18° either side of the midline (Expt. 1 When faced with a choice between a familiar and an unfamiliar bird at different distances, hens chose the familiar bird if the choice could be made 8 cm away but their choices were random if they had to chose 66 or 124 cm away (Expt. 2). This suggests that hens may be unable to discriminate familiar from unfamiliar birds except when they are very close to them. Observations of freely moving birds suddenly confronted with another hen (Expt. 3) showed that even when the object bird was familiar, it was in all cases initially scrutinized from a close distance (26 cm or less), which is consistent with the hypothesis that hens are unable to recognize other birds except when close en...
Using video recordings of hens, Gallus gallus domesticus, as they approached different kinds of o... more Using video recordings of hens, Gallus gallus domesticus, as they approached different kinds of objects, I examined how change in object distance is associated with a change from lateral to binocular viewing. The birds tended to view distant objects laterally while they preferentially viewed objects less than 20-30 cm away frontally; this was true whether they were looking at another bird or at an inanimate object. However, as well as switching between lateral and frontal viewing, the hens also swung their heads from side to side with movements so large that the same object appeared to be viewed with completely different parts of the retina, and even with different eyes, in rapid succession. When confronted with a novel object, the hens walked more slowly but continued to show large head movements. This suggests that, unlike mammals, which gaze fixedly at novel objects, hens investigate them by moving the head and looking at them with different, specialized, parts of their eyes. Many aspects of bird behaviour, such as search image formation, vigilance and visual discriminations, may be affected by the way they move the head and eyes.
Artificial visual stimuli in the form of photographs, video sequences and computer-generated imag... more Artificial visual stimuli in the form of photographs, video sequences and computer-generated images are increasingly being used to explore the visual world of birds but their use is controversial as it is still not clear whether birds see them in the same way that humans do. While differences between bird and human colour vision may be one problem with using such artificial images, another and potentially even more important difficulty is the distance at which stimuli are presented. An experiment is described in which hens, Gallus gallus domesticus, were trained to move towards one of two real objects viewed at two different distances. Even for real objects, discrimination levels were better when the hens were allowed to view the stimuli from 5-25 cm than when they were forced to choose at 120 cm and this correlated with their ability to transfer to photographs of the same objects at different distances. In a colour discrimination at a short distance, five out of seven hens showed 100% correct responses when first shown photographs of real objects that they had previously learnt to discriminate. The results suggest that photographs can be used as substitutes for real stimuli but that care should be taken over the distance at which they are presented. The results are discussed in relation to the visual behaviour of birds and differences in functioning of their frontal and lateral visual fields.
The difficulties of defining the space needs of poultry are only partly due to methodological dis... more The difficulties of defining the space needs of poultry are only partly due to methodological discrepancies between studies and therefore only partly rectifiable by more research along previous lines. “Space” for poultry is far more complex than can be summed up in one single number and too much reliance on stocking density without considering what space contains is unlikely to improve welfare. Space needs are considered in relation to effects of varying amounts of space on bird physical health, their social responses, and their responses to enrichments. Space needs have been measured in various ways including the animals’ own preferences, spatial distribution, area covered, and behavior linked with positive and negative affect. A possible way forward is to be more specific about the space needs that poultry have for performing specific behavior patterns that either have an effect on their health or can be demonstrated to be important to the birds themselves.
Footpad dermatitis and hockburn are serious welfare and economic issues for the production of bro... more Footpad dermatitis and hockburn are serious welfare and economic issues for the production of broiler (meat) chickens. The authors here describe the use of an inexpensive camera system that monitors the movements of broiler flocks throughout their lives and suggest that it is possible to predict, even in young birds, the cross-sectional prevalence at slaughter of footpad dermatitis and hockburn before external signs are visible. The skew and kurtosis calculated from the authors' camera-based optical flow system had considerably more power to predict these outcomes in the 50 flocks reported here than water consumption, bodyweight or mortality and therefore have the potential to inform improved flock management through giving farmers early warning of welfare issues. Further trials are underway to establish the generality of the results.
Precision livestock farming (PLF) systems have the potential to improve animal welfare 26 through... more Precision livestock farming (PLF) systems have the potential to improve animal welfare 26 through providing a continuous picture of welfare states in real time and enabling fast interventions 27 that benefit the current flock. However, it remains unclear whether the goal of PLF development 28 has been to improve welfare or increase production efficiency. The aims of this systematic literature 29 review are to provide an overview of the current state of PLF in poultry farming and investigate 30 whether the focus of PLF research has been to improve bird welfare. The study characteristics 31 extracted from 264 peer-reviewed publications and conference proceedings suggest that poultry 32 PLF has received increasing attention on a global scale, but is yet to become a widespread 33 commercial reality. PLF development has most commonly focussed on broiler farming, followed by 34 laying hens, and mainly involves the use of sensors (environmental and wearable) and cameras. 35 More publicatio...
“Smart” or “precision” farming has revolutionized crop agriculture but its application to livesto... more “Smart” or “precision” farming has revolutionized crop agriculture but its application to livestock farming has raised ethical concerns because of its possible adverse effects on animal welfare. With rising public concern for animal welfare across the world, some people see the efficiency gains offered by the new technology as a direct threat to the animals themselves, allowing producers to get “more for less” in the interests of profit. Others see major welfare advantages through life-long health monitoring, delivery of individual care and optimization of environmental conditions. The answer to the question of whether smart farming improves or damages animal welfare is likely to depend on three main factors. Firstly, much will depend on how welfare is defined and the extent to which politicians, scientists, farmers and members of the public can agree on what welfare means and so come to a common view on how to judge how it is impacted by technology. Defining welfare as a combination of good health and what the animals themselves want provides a unifying and animal-centered way forward. It can also be directly adapted for computer recognition of welfare. A second critical factor will be whether high welfare standards are made a priority within smart farming systems. To achieve this, it will be necessary both to develop computer algorithms that can recognize welfare to the satisfaction of both the public and farmers and also to build good welfare into the control and decision-making of smart systems. What will matter most in the end, however, is a third factor, which is whether smart farming can actually deliver its promised improvements in animal welfare when applied in the real world. An ethical evaluation will only be possible when the new technologies are more widely deployed on commercial farms and their full social, environmental, financial and welfare implications become apparent.
The impact of production systems on the welfare of ducks grown for meat is becoming increasingly ... more The impact of production systems on the welfare of ducks grown for meat is becoming increasingly controversial. In the UK, approximately 18 million ducks (Anas platyrhynchos) were reared for meat in 2006 (British Poultry Council, 2008; http://www.poultry.uk.com/ who_ducks01.htm). Despite the association between ducks and water in the wild, there are no legal requirements for them to have water for bathing or swimming. Some have troughs in which they dip their heads and splash water onto their bodies but for some, their only contact with water is drinking water from ball-bearing ‘nipples’. The Council of Europe (1999) recommends that ducks should be able to dip their heads in water and spread water over their feathers. We here provide clear evidence that duck welfare is related to the nature and extent of their access to water. We recorded body and plumage condition and undertook three behavioural techniques to assess the effect of water source on the welfare of ducks. Ducks were rea...
A study was conducted to evaluate activity changes in pigs associated with the development of tai... more A study was conducted to evaluate activity changes in pigs associated with the development of tail-biting outbreaks using optical flow algorithms. Pigs (n = 120; initial body weight = 25 ± 2.9 kg) housed in four pens of 30 pigs were studied for 13 weeks. Outbreaks of tail biting were registered through daily observations. Behavior of pigs in each pen was video-recorded. Three one-hour video segments, representing morning, noon, and afternoon on days 10, 7, and 3 before and during the first outbreak of tail biting were scanned at 5-min intervals to estimate time budget for lying, standing, eating, drinking, pig-directed behavior, and tail biting. The same video segments were analyzed for optical flow. Mean optical flow was higher three days before and during the tail-biting outbreak, compared to 10 days before the outbreak (p < 0.05), suggesting that pigs may increase their activity three days before tail-biting outbreaks. All optical flow measures (mean, variance, skewness, and k...
this problem using simulations. We find (1) that the most successful strategies involve a limited... more this problem using simulations. We find (1) that the most successful strategies involve a limited period of assessment followed by a stable relationship in which fights are avoided and (2) that the duration of assessment depends both on the costliness of fighting and on the difference between the animals' RHPs. Along with our direct work on modeling and simulations, we develop extensive software to facilitate further testing; it is available at https: //bitbucket.org/CameronLHall/dominancesharingassessmentmatlab/.
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, a... more JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK * Contact for c... more Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK * Contact for correspondence and requests for reprints: [email protected] ... Commercially reared broiler chickens are commonly supplied with drinking water through lines of nipple ...
ABSTRACTContaminated chicken meat is a major source of human Campylobacteriosis and rates of infe... more ABSTRACTContaminated chicken meat is a major source of human Campylobacteriosis and rates of infection remain high, despite efforts to limit the colonisation of broiler (meat) chicken flocks on farms. Using conventional testing methods of culture or qPCR, Campylobacter is typically detected amongst broiler flocks from 3 weeks of age, leading to the assumption that infection is introduced horizontally into chicken rearing houses at this time. In this study, we use parallel sequencing of a fragment of the Campylobacter outer membrane protein, encoded by the porA gene, to test for presence of Campylobacter DNA amongst fresh faecal samples collected from broiler flocks aged 23-28 days. Campylobacter DNA was detected in all of the 290 samples tested using the porA target, and in 48% of samples using 16S bacterial profiling, irrespective of whether or not Campylobacter could be detected using conventional qPCR thresholds. A single porAf2 variant was predominant amongst flocks that would b...
We formulate a mathematical model for daily activities of a cow (eating, lying down, and standing... more We formulate a mathematical model for daily activities of a cow (eating, lying down, and standing) in terms of a piecewise affine dynamical system. We analyze the properties of this bovine dynamical system representing the single animal and develop an exact integrative form as a discrete-time mapping. We then couple multiple cow "oscillators" together to study synchrony and cooperation in cattle herds. We comment on the relevant biology and discuss extensions of our model. With this abstract approach, we not only investigate equations with interesting dynamics but also develop interesting biological predictions. In particular, our model illustrates that it is possible for cows to synchronize less when the coupling is increased.
When definitions and explanations are provided for key points in science, students' understanding... more When definitions and explanations are provided for key points in science, students' understanding of the whole field is enhanced. Unravelling Animal Behavior does an excellent job of providing definitions and explanations for some important current research areas in ethology (adaptation, optimality, inclusive fitness, behavioral genetics, neurophysiology, communication, evolutionary stable strategies and sexual selection) and older areas that should die (instinct and fixed action pattern). Advantages: The writing is lucid, and summaries end each chapter. Very clear explanations are given for: how bats echolocate; the advantage of helping close kin; dynamics maintaining a 50:50 sex ratio; how particular environments support the expression of genetic traits; why "innate" and "learned" are not dichotomous. Disadvantages: Classical studies are reviewed without citation of recent studies that update or refute the original studies. Omissions include recent research on learning and consideration of group selection (p. 135). Some complex topics, such as evolutionary stable strategies, should be explained in more detail. Recent developments in molecular biology probably contradict some behavioral genetics conclusions. A few terms (allele, pleiotropy, variance) are undefined, and redundancy is high. More photographs and diagrams that explain points wouldI
Group level measures of welfare flocks have been criticized on the grounds that they give only av... more Group level measures of welfare flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that the group-level optical flow patterns made by broiler flocks can be used to deliver information not just about the flock averages but also about the proportion of individuals in different movement categories. Mean optical flow provides information about the average movement of the whole flock while the variance, skew and kurtosis quantify the variation between individuals. We correlated flock optical flow patterns with the behavior and welfare of a sample of 16 birds per flock in two runway tests and a water (latency-to-lie) test. In the runway tests, there was a positive correlation between the average time taken to complete the runway and the skew and kurtosis of optical flow on day 28 of flock life (on average slow individuals came from flocks with a high skew and kurtosis). In the water test, th...
Group level measures of welfare such as the optical flow patterns made by broiler chicken flocks ... more Group level measures of welfare such as the optical flow patterns made by broiler chicken flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that by using the skew and kurtosis in addition to the mean, optical flow patterns can be used to deliver information not just about the flock average but also about the proportion of individuals in different movement categories. We correlated flock optical flow patterns with the behaviour of a sample of 16 birds per flock in two runway tests and a water (latency-to-lie) test. In the runway tests, there was a positive correlation between the time taken to complete the runway and the skew and kurtosis of optical flow on day 28 of flock life (slow individuals came from flocks with a high skew and kurtosis). In the water test, there was a positive correlation between the length of time the birds remained standing and the mean and variance of flock op...
When shown familiar and unfamiliar birds at different distances, hens viewed birds 0.7 m or 1.4 m... more When shown familiar and unfamiliar birds at different distances, hens viewed birds 0.7 m or 1.4 m away with modal head angles between 54° and 72° from the midline, using the lateral visual field but viewed birds closer (less than 20 cm) binocularly, with the head within 18° either side of the midline (Expt. 1 When faced with a choice between a familiar and an unfamiliar bird at different distances, hens chose the familiar bird if the choice could be made 8 cm away but their choices were random if they had to chose 66 or 124 cm away (Expt. 2). This suggests that hens may be unable to discriminate familiar from unfamiliar birds except when they are very close to them. Observations of freely moving birds suddenly confronted with another hen (Expt. 3) showed that even when the object bird was familiar, it was in all cases initially scrutinized from a close distance (26 cm or less), which is consistent with the hypothesis that hens are unable to recognize other birds except when close en...
Using video recordings of hens, Gallus gallus domesticus, as they approached different kinds of o... more Using video recordings of hens, Gallus gallus domesticus, as they approached different kinds of objects, I examined how change in object distance is associated with a change from lateral to binocular viewing. The birds tended to view distant objects laterally while they preferentially viewed objects less than 20-30 cm away frontally; this was true whether they were looking at another bird or at an inanimate object. However, as well as switching between lateral and frontal viewing, the hens also swung their heads from side to side with movements so large that the same object appeared to be viewed with completely different parts of the retina, and even with different eyes, in rapid succession. When confronted with a novel object, the hens walked more slowly but continued to show large head movements. This suggests that, unlike mammals, which gaze fixedly at novel objects, hens investigate them by moving the head and looking at them with different, specialized, parts of their eyes. Many aspects of bird behaviour, such as search image formation, vigilance and visual discriminations, may be affected by the way they move the head and eyes.
Artificial visual stimuli in the form of photographs, video sequences and computer-generated imag... more Artificial visual stimuli in the form of photographs, video sequences and computer-generated images are increasingly being used to explore the visual world of birds but their use is controversial as it is still not clear whether birds see them in the same way that humans do. While differences between bird and human colour vision may be one problem with using such artificial images, another and potentially even more important difficulty is the distance at which stimuli are presented. An experiment is described in which hens, Gallus gallus domesticus, were trained to move towards one of two real objects viewed at two different distances. Even for real objects, discrimination levels were better when the hens were allowed to view the stimuli from 5-25 cm than when they were forced to choose at 120 cm and this correlated with their ability to transfer to photographs of the same objects at different distances. In a colour discrimination at a short distance, five out of seven hens showed 100% correct responses when first shown photographs of real objects that they had previously learnt to discriminate. The results suggest that photographs can be used as substitutes for real stimuli but that care should be taken over the distance at which they are presented. The results are discussed in relation to the visual behaviour of birds and differences in functioning of their frontal and lateral visual fields.
The difficulties of defining the space needs of poultry are only partly due to methodological dis... more The difficulties of defining the space needs of poultry are only partly due to methodological discrepancies between studies and therefore only partly rectifiable by more research along previous lines. “Space” for poultry is far more complex than can be summed up in one single number and too much reliance on stocking density without considering what space contains is unlikely to improve welfare. Space needs are considered in relation to effects of varying amounts of space on bird physical health, their social responses, and their responses to enrichments. Space needs have been measured in various ways including the animals’ own preferences, spatial distribution, area covered, and behavior linked with positive and negative affect. A possible way forward is to be more specific about the space needs that poultry have for performing specific behavior patterns that either have an effect on their health or can be demonstrated to be important to the birds themselves.
Footpad dermatitis and hockburn are serious welfare and economic issues for the production of bro... more Footpad dermatitis and hockburn are serious welfare and economic issues for the production of broiler (meat) chickens. The authors here describe the use of an inexpensive camera system that monitors the movements of broiler flocks throughout their lives and suggest that it is possible to predict, even in young birds, the cross-sectional prevalence at slaughter of footpad dermatitis and hockburn before external signs are visible. The skew and kurtosis calculated from the authors' camera-based optical flow system had considerably more power to predict these outcomes in the 50 flocks reported here than water consumption, bodyweight or mortality and therefore have the potential to inform improved flock management through giving farmers early warning of welfare issues. Further trials are underway to establish the generality of the results.
Precision livestock farming (PLF) systems have the potential to improve animal welfare 26 through... more Precision livestock farming (PLF) systems have the potential to improve animal welfare 26 through providing a continuous picture of welfare states in real time and enabling fast interventions 27 that benefit the current flock. However, it remains unclear whether the goal of PLF development 28 has been to improve welfare or increase production efficiency. The aims of this systematic literature 29 review are to provide an overview of the current state of PLF in poultry farming and investigate 30 whether the focus of PLF research has been to improve bird welfare. The study characteristics 31 extracted from 264 peer-reviewed publications and conference proceedings suggest that poultry 32 PLF has received increasing attention on a global scale, but is yet to become a widespread 33 commercial reality. PLF development has most commonly focussed on broiler farming, followed by 34 laying hens, and mainly involves the use of sensors (environmental and wearable) and cameras. 35 More publicatio...
“Smart” or “precision” farming has revolutionized crop agriculture but its application to livesto... more “Smart” or “precision” farming has revolutionized crop agriculture but its application to livestock farming has raised ethical concerns because of its possible adverse effects on animal welfare. With rising public concern for animal welfare across the world, some people see the efficiency gains offered by the new technology as a direct threat to the animals themselves, allowing producers to get “more for less” in the interests of profit. Others see major welfare advantages through life-long health monitoring, delivery of individual care and optimization of environmental conditions. The answer to the question of whether smart farming improves or damages animal welfare is likely to depend on three main factors. Firstly, much will depend on how welfare is defined and the extent to which politicians, scientists, farmers and members of the public can agree on what welfare means and so come to a common view on how to judge how it is impacted by technology. Defining welfare as a combination of good health and what the animals themselves want provides a unifying and animal-centered way forward. It can also be directly adapted for computer recognition of welfare. A second critical factor will be whether high welfare standards are made a priority within smart farming systems. To achieve this, it will be necessary both to develop computer algorithms that can recognize welfare to the satisfaction of both the public and farmers and also to build good welfare into the control and decision-making of smart systems. What will matter most in the end, however, is a third factor, which is whether smart farming can actually deliver its promised improvements in animal welfare when applied in the real world. An ethical evaluation will only be possible when the new technologies are more widely deployed on commercial farms and their full social, environmental, financial and welfare implications become apparent.
The impact of production systems on the welfare of ducks grown for meat is becoming increasingly ... more The impact of production systems on the welfare of ducks grown for meat is becoming increasingly controversial. In the UK, approximately 18 million ducks (Anas platyrhynchos) were reared for meat in 2006 (British Poultry Council, 2008; http://www.poultry.uk.com/ who_ducks01.htm). Despite the association between ducks and water in the wild, there are no legal requirements for them to have water for bathing or swimming. Some have troughs in which they dip their heads and splash water onto their bodies but for some, their only contact with water is drinking water from ball-bearing ‘nipples’. The Council of Europe (1999) recommends that ducks should be able to dip their heads in water and spread water over their feathers. We here provide clear evidence that duck welfare is related to the nature and extent of their access to water. We recorded body and plumage condition and undertook three behavioural techniques to assess the effect of water source on the welfare of ducks. Ducks were rea...
A study was conducted to evaluate activity changes in pigs associated with the development of tai... more A study was conducted to evaluate activity changes in pigs associated with the development of tail-biting outbreaks using optical flow algorithms. Pigs (n = 120; initial body weight = 25 ± 2.9 kg) housed in four pens of 30 pigs were studied for 13 weeks. Outbreaks of tail biting were registered through daily observations. Behavior of pigs in each pen was video-recorded. Three one-hour video segments, representing morning, noon, and afternoon on days 10, 7, and 3 before and during the first outbreak of tail biting were scanned at 5-min intervals to estimate time budget for lying, standing, eating, drinking, pig-directed behavior, and tail biting. The same video segments were analyzed for optical flow. Mean optical flow was higher three days before and during the tail-biting outbreak, compared to 10 days before the outbreak (p < 0.05), suggesting that pigs may increase their activity three days before tail-biting outbreaks. All optical flow measures (mean, variance, skewness, and k...
this problem using simulations. We find (1) that the most successful strategies involve a limited... more this problem using simulations. We find (1) that the most successful strategies involve a limited period of assessment followed by a stable relationship in which fights are avoided and (2) that the duration of assessment depends both on the costliness of fighting and on the difference between the animals' RHPs. Along with our direct work on modeling and simulations, we develop extensive software to facilitate further testing; it is available at https: //bitbucket.org/CameronLHall/dominancesharingassessmentmatlab/.
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