Commentary The role of the veterinary profession in promoting animal welfare Barry S. Kipperman, DVM
T
he beginning of the modern era of concern for animal welfare is often linked to the 1965 release of the Brambell report1 in the United Kingdom, which suggested that to ensure good welfare, an animal should have “sufficient freedom of movement to be able without difficulty to turn around, groom itself, get up, lie down and stretch its limbs.” Subsequently, the idea of the five freedoms (freedom from hunger and thirst; freedom from discomfort; freedom from pain, injury, and disease; freedom to express normal behavior; and freedom from fear and distress) emerged as a cornerstone of farm animal welfare policy in Great Britain.2 The five freedoms primarily focus on minimizing suffering and providing essential needs. A more comprehensive view of animal welfare that considers the perspective of the animal, rather than just the animal’s value to humans, has since been developed. This more contemporary interpretation takes into consideration not only the physical health (ie, whether the animals are free from pain, hunger, thirst, injury, and disease) of the animals under our supervision but also their mental health (ie, whether the animals suffer from the negative effects of stress and fear and whether they have opportunities for positive experiences such as play, touch, choice, or freedoma) and ability to satisfy behavioral needs (ie, specific behavior patterns that when prevented, result in frustration or a negative psychological state3). Veterinarians are in a unique position to influence animal welfare standards by virtue of our scientific training and the trust animal caretakers place in us. Concern for animal welfare prompted a revision of the veterinarian’s oath in 20104 to add the words and welfare: “I solemnly swear to use my scientific knowledge and skills for the benefit of society through the protection of animal health and welfare….” This acknowledged a change in the purview of the profession beyond that of physical health alone. Too often, however, the animal welfare policies adopted by the AVMA emphasize physical health to a greater extent than animals’ mental states or ability to express natural behaviors, particularly when it comes to farm animal welfare. I contend that these views on farm animal welfare lag behind those of society as a whole and that by continuing to espouse these positions, the AVMA risks abandoning its role as an advocate for the welfare of farm animals. An examination of just two issues—battery cage confinement of laying hens and confinement of breeding sows in gestation crates—illustrates my concerns. From Veterinary Emergency and Specialist Care Center, 7660 Amador Valley Blvd, Dublin, CA 94568. Address correspondence to Dr. Kipperman ([email protected]). 502
Views: Commentary
Battery Cage Confinement of Laying Hens Approximately 98% of the 295 million laying hens providing eggs in the United States are confined in battery cages.5,6 Current recommendations by the United Egg Producers are to allot 67 to 86 square inches per bird.7 A typical cage is about the size of a filing cabinet drawer, and there are 8 to 10 birds per cage, with the cages stacked on top of each other in rows. The birds’ beaks are routinely trimmed to mitigate injuries to other birds. The hens spend their entire lives in these cages, laying an egg approximately every 36 hours until they are no longer productive. This degree of confinement precludes movements such as wing stretching or flapping, which requires > 140 square inches per bird.8 Battery cages do not have perches or nests, precluding the hens from expressing natural behaviors such as perching and nesting.8 Hens are highly motivated to perch, especially at night, and hen arousal levels are reduced with access to perching; according to Broom et al,9 the “strong preferences that most hens have for using a perch…show that the provision of perches improves welfare.” With regard to the behavioral need to nest, a 2006 study10 concluded that “Hens place a high value on access to discrete closed nest sites.… They are prepared to pay high prices such as squeezing through narrow gaps or opening doors to gain access to nest boxes before egg laying. Moreover, hens have been found to work as hard for a nest site…as they would for food following… periods of deprivation.” Further, it has been demonstrated that hens in cages without access to a nest box spent > 20% of the hour before egg laying walking and pacing, whereas hens with a nest box spent only 7% of this time walking and pacing.11 Lack of a secluded nest box to fulfill the hen’s behavioral need to nest is considered one of the biggest welfare concerns in conventional cage systems.3 Proposed advantages of battery cages, compared with litter-based systems, include reduced exposure to parasites, environmental hazards, and predators; improved egg production, cost-efficiency, and monitoring of individual birds; reduced incidence of infectious diseases; and improved air quality. Alternative means of housing, such as cage-free systems and cages that provide nest boxes, perches, and litter, allow for the expression of natural behaviors but have potential disadvantages of increased exposure to disease vectors, poor air quality, and feather pecking, which can result in high mortality rates in select large flocks.12 A recent review by Freire and Cowling13 comparing data on laying hens housed in battery cages versus alternative systems found that egg production was higher JAVMA, Vol 246, No. 5, March 1, 2015
in battery cages, but birds manifested more comfort behaviors such as wing flapping in the alternative systems. Most importantly, the authors concluded that hen mortality rate and the incidence of feather pecking and body wounds did not differ between systems. In developing welfare policies for laying hens, the veterinary profession must find a balance between meeting the psychological needs of hens and limiting their exposure to hazards and infectious agents. The current AVMA policy takes no position on battery cages,14 stating, “Laying hen housing systems must provide feed, water, light, air quality, space and sanitation.” The policy suggests that “[h]ousing systems should provide for expression of important natural behaviors,” and directs readers to additional resources on the positive and negative welfare implications of barren and enriched cages and cage-free housing.12,15 Confinement of Breeding Sows in Gestation Crates About 70% of the 6 million breeding sows each year in the United States spend their 4-month gestation period confined in individual 2 X 7-foot stalls that are so small that the sows cannot turn around or lie down comfortably.6 This method of confinement precludes manifesting natural behaviors such as rooting, nesting, and socializing with other pigs. Rationales cited for crate confinement include improved observation and ease of management of individual pigs; reduced labor costs, physical plant costs, and food requirements; reduced incidences of aggression and infectious diseases; and improved environmental control. In contrast, the greater incidence of stereotypical behaviors in stall-housed sows, compared with grouphoused sows,16,17 suggests that the welfare of pigs housed in these crates is compromised. Stereotypical behaviors are recurrent behaviors such as sham chewing (chewing and excessive drooling unassociated with feeding) and bar biting (chewing on bars of the stall) that appear to have no evolutionary function and are believed to arise from boredom or frustration.18 In nature, sows seek a secluded site prior to farrowing to gather materials to make a nest.3 Lack of nesting materials in gestation crate systems has been shown to induce signs of frustration including restlessness, stereotypical rooting, and ground pawing.19 Alternatives to gestation crates include turn-around stalls and group housing. Purported disadvantages of these alternative systems include increased costs and space, potential aggression between pigs, and exposure to the elements if pigs are housed outdoors. In creating welfare policies for pregnant sows, the veterinary profession must find a balance between satisfying the psychological needs of sows and protecting them from aggression and disease. The current AVMA policy20 on pregnant sow housing states that housing systems should “Provide sows with adequate quality and quantity of space that allows sows to assume normal postures and express normal patterns of behavior.… Stall systems restrict normal behavioral expression.” Because gestation stalls prevent the expression of normal behaviors, then it seems that it should JAVMA, Vol 246, No. 5, March 1, 2015
follow that this method of confinement would not be condoned as a housing option. However, rather than advising against the use of gestation crates, the policy states, “There are advantages and disadvantages to any sow housing system.” The AVMA and Animal Welfare The AVMA is not a regulatory body and does not control the conditions under which animals are raised or housed. Still, its views are influential in shaping public policy. In 2013, for instance, Governor Chris Christie of New Jersey vetoed a bill that would have banned the use of gestation crates in the state, citing that neither the AVMA nor the American Association of Swine Veterinarians had called for banning them.21 The AVMA wishes to be identified as a leader in the area of animal welfare. Too often, however, its animal welfare policies—as exemplified by its policies on layer hen and pregnant sow housing—appear to emphasize select aspects of physical health over animals’ mental health or ability to express natural behaviors. In 2008, for example, a California referendum known as the Standards for Confining Farm Animals, or Proposition 2, called for providing egg-laying hens, veal calves, and pregnant sows in the state enough room to lie down, stand, turn around, and fully extend their limbs. This referendum passed with the support of 63.5% of those who voted.22 The AVMA took no official position on the ballot initiative, stating that the association was “concerned that legislating isolated, arbitrary and emotion-based criteria to implement farm animal housing systems may actually do more harm than good for the well-being of the animals while compromising the sustainability of production systems that are essential to ensure we continue to have the safest, most affordable, and abundant food supply in the world.” This statement suggests that the AVMA placed a higher value on the cost-effectiveness of farm animal confinement than on the effects of that confinement on the mental health of the animals or their ability to manifest natural behaviors. Words Matter The AVMA Animal Welfare Principles23 state, “The responsible use of animals for human purposes, such as companionship, food, fiber, recreation, work, education, exhibition, and research conducted for the benefit of both humans and animals, is consistent with the Veterinarian’s Oath.” One could characterize our interactions with animals in numerous ways; thus, the choice of certain language suggests a particular viewpoint. To my mind, we use things but we care for animals. In contrast, this statement in the AVMA Animal Welfare Principles suggests that we can treat animals as we wish, with our only duty being to use them responsibly. Similarly, the common designation within the veterinary profession of farm animals as production animals does not, I believe, foster empathy for chickens, cattle, or pigs and suggests that they have a moral status different from those species identified as companion animals. Views: Commentary
503
Conclusion Although providing laying hens and pregnant sows with increased living space does not assure them a positive welfare state, it would be an important step in ameliorating what I believe to be a profoundly negative welfare state. An argument can be made that all laying hens kept in battery cages and all sows confined in gestation crates endure a lifetime of frustration and poor mental health owing to an inability to express natural behaviors. In contrast, only some animals housed in alternative housing systems will develop infectious disease, be subject to aggression, or die prematurely. Even if there is a risk that the welfare of some animals would be diminished, shouldn’t veterinarians advocate for improving the welfare of all animals in the aggregate? Candace Croney, PhD, who was recently chosen to oversee Purdue University’s new Center for Animal Welfare Science,24 has written that veterinarians are not yet perceived by scholars as leaders and opinion shapers on the issue of farm animal welfare.25 She goes on to write that “the U.S. veterinary medical community appears to have no cohesive message about either animals or animal welfare” and suggests that “within veterinary medicine, there are irreconcilable differences in the views of animals as instruments or commodities versus the increasingly popular view of animals as companions…. Dissonant professional views may also serve to exacerbate existing societal conflicts about the role of animals in society and what constitutes appropriate animal treatment.” The AVMA’s policies on layer hen and pregnant sow housing seem to reflect these dissonant views. In addition, the association’s views on farm animal welfare, in general, lag behind those of society, as reflected by the passage of numerous legislative initiatives and industry mandates in the past decade to phase out use of battery cages and gestation crates, despite the lack of AVMA support. If the AVMA and the veterinary profession as a whole wish to retain credibility as leaders on animal welfare issues, then modifying its policies and positions to better reflect evolving societal values and ascribing at least as much importance to mental health and natural behaviors as to physical health would be a good starting point. The public, animal advocacy groups, and veterinarians themselves expect the AVMA to not only mirror the changing roles of animals in society but also to act as a leader in guiding and improving our stewardship of all animals.
4.
a.
22.
Balcombe J. Animal pleasure (oral presentation). Sci Anim Think Emot Sentience Factor Policy Pract, Washington, DC, March 2014.
References 1. 2.
3. 504
Brambell FWR. Report of the Technical Committee to enquire into the welfare of animals kept under intensive livestock husbandry systems. London: Her Majesty’s Stationery Office, 1965. Farm Animal Welfare Council. Farm animal welfare in Great Britain: past, present and future. October 2009. Available at: https:// www.gov.uk/government/uploads/system/uploads/attachment_ data/file/319292/Farm_Animal_Welfare_in_Great_Britain_-_ Past__Present_and_Future.pdf. Accessed Dec 1, 2014. Widowski T. Why are behavioural needs important? In: Grandin T, Views: Commentary
5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
16. 17.
18. 19. 20. 21.
23. 24. 25.
ed. Improving animal welfare. A practical approach. Cambridge, Mass: CAB International, 2010;290–309. AVMA. Veterinarian’s oath revised to emphasize animal welfare commitment. Jan 1, 2011. Available at www.avma.org/News/ JAVMANews/Pages/x110101a.aspx. Accessed Jul 2, 2014. American Egg Board. About the US egg industry. Available at: www.aeb.org/farmers-and-marketers/industry-overview. Accessed Aug 16, 2014. Wolfson D, Sullivan M. Foxes in the henhouse; animals, agribusiness and the law. In: Sunstein CR, Nussbaum MC, eds. Animal rights. New York: Oxford University Press, 2004;205–234. United Egg Producers. Animal husbandry guidelines for US egg laying flocks. Available at: www.uepcertified.com/pdf/2010uep-animal-welfare-guidelines.pdf. Accessed Sep 12, 2014. Swanson JC. How welfare is measured and why scientists do it differently. J Vet Med Educ 2010;37:89–93. Broom DM, Fraser AF. The welfare of poultry. In: Domestic animal behavior and welfare. 4th ed. Cambridge, Mass: CAB International, 2007;281–301. Weeks CA, Nicol CJ. Behavioural needs, priorities and preferences of laying hens. Worlds Poult Sci J 2006;62:296–307. Yue S, Duncan IJH. Frustrated nesting behavior; relation to extra-cuticular shell calcium and bone strength in White Leghorn hens. Br Poult Sci 2003;44:175–181. AVMA. Welfare implications of laying hen housing. Available at: www.avma.org/KB/Resources/LiteratureReviews/Documents/ laying_hen_housing_bgnd.pdf. Accessed Aug 17, 2014. Freire R, Cowling A. The welfare of laying hens in conventional cages and alternative systems: first steps towards a quantitative comparison. Anim Welf 2013;22:57–65. AVMA. Layer hen housing systems. Available at: https://www. avma.org/KB/Policies/Pages/Layer-Hen-Housing-Systems.aspx. Accessed Aug 16, 2014. AVMA. A comparison of cage and non-cage systems for housing laying hens. Available at: https://www.avma.org/KB/Resources/ Reference/AnimalWelfare/Pages/AVMA-issues-A-Comparisonof-Cage-and-Non-Cage-Systems-for-Housing-Laying-Hens. aspx. Accessed Dec 12, 2014. Broom DM, Fraser AF. The welfare of pigs. In: Domestic animal behavior and welfare. 4th ed. Cambridge, Mass: CAB International, 2007;272–281. Waiblinger S. Animal welfare and housing. In: Smulders FJM, Algers B, eds. Welfare of production animals; assessment and management of risks. Wageningen, The Netherlands: Wageningen Academic Publishers, 2009;79–113. Broom DM, Fraser AF. Abnormal behavior 1; stereotypies. In: Domestic animal behavior and welfare. 4th ed. Cambridge, Mass: CAB International, 2007;226–235. Wischner D, Kemper N, Krieter J. Nest-building behavior in sows and consequences for pig husbandry. Livest Sci 2009;124:1–8. AVMA. Pregnant sow housing. Available at: www.avma.org/KB/ Policies/Pages/Pregnant-Sow-Housing.aspx. Accessed Aug 2, 2014. Hanna M. New Jersey activists target controversial pig-raising method. Available at: articles.philly.com/2013–09–30/ news/42505154_1_gestation-crates-humane-society-pigs. Accessed Aug 2, 2014. Nolen RS. AVMA weighs in on California livestock housing referendum. Proposal could be harmful, AVMA says; sparks discord within CVMA. J Am Vet Med Assoc 2008;233:1026–1028. AVMA. AVMA animal welfare principles. Available at: https://www. avma.org/KB/Policies/Pages/AVMA-Animal-Welfare-Principles. aspx. Accessed Aug 1, 2014. Croney chosen to head Purdue animal welfare center. J Am Vet Med Assoc 2014;244:640. Croney CC. Words matter: implications of semantics and imagery in framing animal-welfare issues. J Vet Med Educ 2010;37:101–106.
For all commentaries, views expressed are those of the authors and do not necessarily reflect the official policy of the AVMA. JAVMA, Vol 246, No. 5, March 1, 2015
T
he beginning of the modern era of concern for animal welfare is often linked to the 1965 release of the Brambell report1 in the United Kingdom, which suggested that to ensure good welfare, an animal should have “sufficient freedom of movement to be able without difficulty to turn around, groom itself, get up, lie down and stretch its limbs.” Subsequently, the idea of the five freedoms (freedom from hunger and thirst; freedom from discomfort; freedom from pain, injury, and disease; freedom to express normal behavior; and freedom from fear and distress) emerged as a cornerstone of farm animal welfare policy in Great Britain.2 The five freedoms primarily focus on minimizing suffering and providing essential needs. A more comprehensive view of animal welfare that considers the perspective of the animal, rather than just the animal’s value to humans, has since been developed. This more contemporary interpretation takes into consideration not only the physical health (ie, whether the animals are free from pain, hunger, thirst, injury, and disease) of the animals under our supervision but also their mental health (ie, whether the animals suffer from the negative effects of stress and fear and whether they have opportunities for positive experiences such as play, touch, choice, or freedoma) and ability to satisfy behavioral needs (ie, specific behavior patterns that when prevented, result in frustration or a negative psychological state3). Veterinarians are in a unique position to influence animal welfare standards by virtue of our scientific training and the trust animal caretakers place in us. Concern for animal welfare prompted a revision of the veterinarian’s oath in 20104 to add the words and welfare: “I solemnly swear to use my scientific knowledge and skills for the benefit of society through the protection of animal health and welfare….” This acknowledged a change in the purview of the profession beyond that of physical health alone. Too often, however, the animal welfare policies adopted by the AVMA emphasize physical health to a greater extent than animals’ mental states or ability to express natural behaviors, particularly when it comes to farm animal welfare. I contend that these views on farm animal welfare lag behind those of society as a whole and that by continuing to espouse these positions, the AVMA risks abandoning its role as an advocate for the welfare of farm animals. An examination of just two issues—battery cage confinement of laying hens and confinement of breeding sows in gestation crates—illustrates my concerns. From Veterinary Emergency and Specialist Care Center, 7660 Amador Valley Blvd, Dublin, CA 94568. Address correspondence to Dr. Kipperman ([email protected]). 502
Views: Commentary
Battery Cage Confinement of Laying Hens Approximately 98% of the 295 million laying hens providing eggs in the United States are confined in battery cages.5,6 Current recommendations by the United Egg Producers are to allot 67 to 86 square inches per bird.7 A typical cage is about the size of a filing cabinet drawer, and there are 8 to 10 birds per cage, with the cages stacked on top of each other in rows. The birds’ beaks are routinely trimmed to mitigate injuries to other birds. The hens spend their entire lives in these cages, laying an egg approximately every 36 hours until they are no longer productive. This degree of confinement precludes movements such as wing stretching or flapping, which requires > 140 square inches per bird.8 Battery cages do not have perches or nests, precluding the hens from expressing natural behaviors such as perching and nesting.8 Hens are highly motivated to perch, especially at night, and hen arousal levels are reduced with access to perching; according to Broom et al,9 the “strong preferences that most hens have for using a perch…show that the provision of perches improves welfare.” With regard to the behavioral need to nest, a 2006 study10 concluded that “Hens place a high value on access to discrete closed nest sites.… They are prepared to pay high prices such as squeezing through narrow gaps or opening doors to gain access to nest boxes before egg laying. Moreover, hens have been found to work as hard for a nest site…as they would for food following… periods of deprivation.” Further, it has been demonstrated that hens in cages without access to a nest box spent > 20% of the hour before egg laying walking and pacing, whereas hens with a nest box spent only 7% of this time walking and pacing.11 Lack of a secluded nest box to fulfill the hen’s behavioral need to nest is considered one of the biggest welfare concerns in conventional cage systems.3 Proposed advantages of battery cages, compared with litter-based systems, include reduced exposure to parasites, environmental hazards, and predators; improved egg production, cost-efficiency, and monitoring of individual birds; reduced incidence of infectious diseases; and improved air quality. Alternative means of housing, such as cage-free systems and cages that provide nest boxes, perches, and litter, allow for the expression of natural behaviors but have potential disadvantages of increased exposure to disease vectors, poor air quality, and feather pecking, which can result in high mortality rates in select large flocks.12 A recent review by Freire and Cowling13 comparing data on laying hens housed in battery cages versus alternative systems found that egg production was higher JAVMA, Vol 246, No. 5, March 1, 2015
in battery cages, but birds manifested more comfort behaviors such as wing flapping in the alternative systems. Most importantly, the authors concluded that hen mortality rate and the incidence of feather pecking and body wounds did not differ between systems. In developing welfare policies for laying hens, the veterinary profession must find a balance between meeting the psychological needs of hens and limiting their exposure to hazards and infectious agents. The current AVMA policy takes no position on battery cages,14 stating, “Laying hen housing systems must provide feed, water, light, air quality, space and sanitation.” The policy suggests that “[h]ousing systems should provide for expression of important natural behaviors,” and directs readers to additional resources on the positive and negative welfare implications of barren and enriched cages and cage-free housing.12,15 Confinement of Breeding Sows in Gestation Crates About 70% of the 6 million breeding sows each year in the United States spend their 4-month gestation period confined in individual 2 X 7-foot stalls that are so small that the sows cannot turn around or lie down comfortably.6 This method of confinement precludes manifesting natural behaviors such as rooting, nesting, and socializing with other pigs. Rationales cited for crate confinement include improved observation and ease of management of individual pigs; reduced labor costs, physical plant costs, and food requirements; reduced incidences of aggression and infectious diseases; and improved environmental control. In contrast, the greater incidence of stereotypical behaviors in stall-housed sows, compared with grouphoused sows,16,17 suggests that the welfare of pigs housed in these crates is compromised. Stereotypical behaviors are recurrent behaviors such as sham chewing (chewing and excessive drooling unassociated with feeding) and bar biting (chewing on bars of the stall) that appear to have no evolutionary function and are believed to arise from boredom or frustration.18 In nature, sows seek a secluded site prior to farrowing to gather materials to make a nest.3 Lack of nesting materials in gestation crate systems has been shown to induce signs of frustration including restlessness, stereotypical rooting, and ground pawing.19 Alternatives to gestation crates include turn-around stalls and group housing. Purported disadvantages of these alternative systems include increased costs and space, potential aggression between pigs, and exposure to the elements if pigs are housed outdoors. In creating welfare policies for pregnant sows, the veterinary profession must find a balance between satisfying the psychological needs of sows and protecting them from aggression and disease. The current AVMA policy20 on pregnant sow housing states that housing systems should “Provide sows with adequate quality and quantity of space that allows sows to assume normal postures and express normal patterns of behavior.… Stall systems restrict normal behavioral expression.” Because gestation stalls prevent the expression of normal behaviors, then it seems that it should JAVMA, Vol 246, No. 5, March 1, 2015
follow that this method of confinement would not be condoned as a housing option. However, rather than advising against the use of gestation crates, the policy states, “There are advantages and disadvantages to any sow housing system.” The AVMA and Animal Welfare The AVMA is not a regulatory body and does not control the conditions under which animals are raised or housed. Still, its views are influential in shaping public policy. In 2013, for instance, Governor Chris Christie of New Jersey vetoed a bill that would have banned the use of gestation crates in the state, citing that neither the AVMA nor the American Association of Swine Veterinarians had called for banning them.21 The AVMA wishes to be identified as a leader in the area of animal welfare. Too often, however, its animal welfare policies—as exemplified by its policies on layer hen and pregnant sow housing—appear to emphasize select aspects of physical health over animals’ mental health or ability to express natural behaviors. In 2008, for example, a California referendum known as the Standards for Confining Farm Animals, or Proposition 2, called for providing egg-laying hens, veal calves, and pregnant sows in the state enough room to lie down, stand, turn around, and fully extend their limbs. This referendum passed with the support of 63.5% of those who voted.22 The AVMA took no official position on the ballot initiative, stating that the association was “concerned that legislating isolated, arbitrary and emotion-based criteria to implement farm animal housing systems may actually do more harm than good for the well-being of the animals while compromising the sustainability of production systems that are essential to ensure we continue to have the safest, most affordable, and abundant food supply in the world.” This statement suggests that the AVMA placed a higher value on the cost-effectiveness of farm animal confinement than on the effects of that confinement on the mental health of the animals or their ability to manifest natural behaviors. Words Matter The AVMA Animal Welfare Principles23 state, “The responsible use of animals for human purposes, such as companionship, food, fiber, recreation, work, education, exhibition, and research conducted for the benefit of both humans and animals, is consistent with the Veterinarian’s Oath.” One could characterize our interactions with animals in numerous ways; thus, the choice of certain language suggests a particular viewpoint. To my mind, we use things but we care for animals. In contrast, this statement in the AVMA Animal Welfare Principles suggests that we can treat animals as we wish, with our only duty being to use them responsibly. Similarly, the common designation within the veterinary profession of farm animals as production animals does not, I believe, foster empathy for chickens, cattle, or pigs and suggests that they have a moral status different from those species identified as companion animals. Views: Commentary
503
Conclusion Although providing laying hens and pregnant sows with increased living space does not assure them a positive welfare state, it would be an important step in ameliorating what I believe to be a profoundly negative welfare state. An argument can be made that all laying hens kept in battery cages and all sows confined in gestation crates endure a lifetime of frustration and poor mental health owing to an inability to express natural behaviors. In contrast, only some animals housed in alternative housing systems will develop infectious disease, be subject to aggression, or die prematurely. Even if there is a risk that the welfare of some animals would be diminished, shouldn’t veterinarians advocate for improving the welfare of all animals in the aggregate? Candace Croney, PhD, who was recently chosen to oversee Purdue University’s new Center for Animal Welfare Science,24 has written that veterinarians are not yet perceived by scholars as leaders and opinion shapers on the issue of farm animal welfare.25 She goes on to write that “the U.S. veterinary medical community appears to have no cohesive message about either animals or animal welfare” and suggests that “within veterinary medicine, there are irreconcilable differences in the views of animals as instruments or commodities versus the increasingly popular view of animals as companions…. Dissonant professional views may also serve to exacerbate existing societal conflicts about the role of animals in society and what constitutes appropriate animal treatment.” The AVMA’s policies on layer hen and pregnant sow housing seem to reflect these dissonant views. In addition, the association’s views on farm animal welfare, in general, lag behind those of society, as reflected by the passage of numerous legislative initiatives and industry mandates in the past decade to phase out use of battery cages and gestation crates, despite the lack of AVMA support. If the AVMA and the veterinary profession as a whole wish to retain credibility as leaders on animal welfare issues, then modifying its policies and positions to better reflect evolving societal values and ascribing at least as much importance to mental health and natural behaviors as to physical health would be a good starting point. The public, animal advocacy groups, and veterinarians themselves expect the AVMA to not only mirror the changing roles of animals in society but also to act as a leader in guiding and improving our stewardship of all animals.
4.
a.
22.
Balcombe J. Animal pleasure (oral presentation). Sci Anim Think Emot Sentience Factor Policy Pract, Washington, DC, March 2014.
References 1. 2.
3. 504
Brambell FWR. Report of the Technical Committee to enquire into the welfare of animals kept under intensive livestock husbandry systems. London: Her Majesty’s Stationery Office, 1965. Farm Animal Welfare Council. Farm animal welfare in Great Britain: past, present and future. October 2009. Available at: https:// www.gov.uk/government/uploads/system/uploads/attachment_ data/file/319292/Farm_Animal_Welfare_in_Great_Britain_-_ Past__Present_and_Future.pdf. Accessed Dec 1, 2014. Widowski T. Why are behavioural needs important? In: Grandin T, Views: Commentary
5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
16. 17.
18. 19. 20. 21.
23. 24. 25.
ed. Improving animal welfare. A practical approach. Cambridge, Mass: CAB International, 2010;290–309. AVMA. Veterinarian’s oath revised to emphasize animal welfare commitment. Jan 1, 2011. Available at www.avma.org/News/ JAVMANews/Pages/x110101a.aspx. Accessed Jul 2, 2014. American Egg Board. About the US egg industry. Available at: www.aeb.org/farmers-and-marketers/industry-overview. Accessed Aug 16, 2014. Wolfson D, Sullivan M. Foxes in the henhouse; animals, agribusiness and the law. In: Sunstein CR, Nussbaum MC, eds. Animal rights. New York: Oxford University Press, 2004;205–234. United Egg Producers. Animal husbandry guidelines for US egg laying flocks. Available at: www.uepcertified.com/pdf/2010uep-animal-welfare-guidelines.pdf. Accessed Sep 12, 2014. Swanson JC. How welfare is measured and why scientists do it differently. J Vet Med Educ 2010;37:89–93. Broom DM, Fraser AF. The welfare of poultry. In: Domestic animal behavior and welfare. 4th ed. Cambridge, Mass: CAB International, 2007;281–301. Weeks CA, Nicol CJ. Behavioural needs, priorities and preferences of laying hens. Worlds Poult Sci J 2006;62:296–307. Yue S, Duncan IJH. Frustrated nesting behavior; relation to extra-cuticular shell calcium and bone strength in White Leghorn hens. Br Poult Sci 2003;44:175–181. AVMA. Welfare implications of laying hen housing. Available at: www.avma.org/KB/Resources/LiteratureReviews/Documents/ laying_hen_housing_bgnd.pdf. Accessed Aug 17, 2014. Freire R, Cowling A. The welfare of laying hens in conventional cages and alternative systems: first steps towards a quantitative comparison. Anim Welf 2013;22:57–65. AVMA. Layer hen housing systems. Available at: https://www. avma.org/KB/Policies/Pages/Layer-Hen-Housing-Systems.aspx. Accessed Aug 16, 2014. AVMA. A comparison of cage and non-cage systems for housing laying hens. Available at: https://www.avma.org/KB/Resources/ Reference/AnimalWelfare/Pages/AVMA-issues-A-Comparisonof-Cage-and-Non-Cage-Systems-for-Housing-Laying-Hens. aspx. Accessed Dec 12, 2014. Broom DM, Fraser AF. The welfare of pigs. In: Domestic animal behavior and welfare. 4th ed. Cambridge, Mass: CAB International, 2007;272–281. Waiblinger S. Animal welfare and housing. In: Smulders FJM, Algers B, eds. Welfare of production animals; assessment and management of risks. Wageningen, The Netherlands: Wageningen Academic Publishers, 2009;79–113. Broom DM, Fraser AF. Abnormal behavior 1; stereotypies. In: Domestic animal behavior and welfare. 4th ed. Cambridge, Mass: CAB International, 2007;226–235. Wischner D, Kemper N, Krieter J. Nest-building behavior in sows and consequences for pig husbandry. Livest Sci 2009;124:1–8. AVMA. Pregnant sow housing. Available at: www.avma.org/KB/ Policies/Pages/Pregnant-Sow-Housing.aspx. Accessed Aug 2, 2014. Hanna M. New Jersey activists target controversial pig-raising method. Available at: articles.philly.com/2013–09–30/ news/42505154_1_gestation-crates-humane-society-pigs. Accessed Aug 2, 2014. Nolen RS. AVMA weighs in on California livestock housing referendum. Proposal could be harmful, AVMA says; sparks discord within CVMA. J Am Vet Med Assoc 2008;233:1026–1028. AVMA. AVMA animal welfare principles. Available at: https://www. avma.org/KB/Policies/Pages/AVMA-Animal-Welfare-Principles. aspx. Accessed Aug 1, 2014. Croney chosen to head Purdue animal welfare center. J Am Vet Med Assoc 2014;244:640. Croney CC. Words matter: implications of semantics and imagery in framing animal-welfare issues. J Vet Med Educ 2010;37:101–106.
For all commentaries, views expressed are those of the authors and do not necessarily reflect the official policy of the AVMA. JAVMA, Vol 246, No. 5, March 1, 2015
