Source: IOWA STATE UNIVERSITY submitted to NRP
AN EXAMINATION OF ARGON GAS FOR ON-FARM ANESTHESIA AND EUTHANASIA OF LIVESTOCK
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
0228098
Grant No.
2012-67021-19363
Cumulative Award Amt.
$480,564.00
Proposal No.
2011-03670
Multistate No.
(N/A)
Project Start Date
Apr 1, 2012
Project End Date
Mar 31, 2017
Grant Year
2012
Program Code
[A1521]- Agricultural Engineering
Recipient Organization
IOWA STATE UNIVERSITY
S. AND 16TH ELWOOD
AMES,IA 50011
Performing Department
Veterinary Medicine
Non Technical Summary
This project contributes to the sustainability and competitiveness of US agriculture by advancing three animal agricultural industries, pork, dairy and veal, regarding two of the most significant animal welfare issues receiving national and international scrutiny -on-farm euthanasia and pain mitigation for routine on-farm surgeries. This project refines existing and practical euthanasia technologies to enhance animal welfare and caretaker satisfaction, and extends the technology to two novel applications - euthanasia of unwanted dairy calves and anesthesia for piglet castration and tail docking surgeries. Novel animal cognition research techniques of conditioned place preference and conditioned human preference tests will be used to "ask the animals how they feel" about induction of insensibility with argon gas versus CO2. These techniques allow researchers to titrate relative aversion by quantifying differences in motivated escape and approach behaviors. In a series of experiments, behavioral observations are integrated with physiologic, neuroendocrine, histologic, health and performance parameters to understand what pigs and calves experience during gas anesthesia and euthanasia with argon and CO2 gases. Science-based empirical information resulting from the proposed animal experiments is supported with analysis of critical social and ethical aspects of these technologies. The integration of the science-based information and the social and ethical aspects will uniquely identify effective and humane practices for developing euthanasia and processing technologies for use by swine and calf raisers in their operations and for their market channels. Furthermore, this project enhances the quality of life for farmers and society as a whole by tackling a significant moral stressor imposed on animal caretakers to determine safe, effective and innovative technologies for mitigating animal suffering during euthanasia and on-farm surgery. By identifying effective, humane and socially acceptable technologies for on-farm euthanasia and anesthesia, this project satisfies human needs for animal protein, economic viability of farm operations and cultivation of domestic and export markets for a sustainable agriculture system.
Animal Health Component
40%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3153410102010%
3153510102060%
3155310102010%
3155310308010%
3156010308010%
Knowledge Area
315 - Animal Welfare/Well-Being and Protection;

Subject Of Investigation
3510 - Swine, live animal; 5310 - Machinery and equipment; 6010 - Individuals; 3410 - Dairy cattle, live animal;

Field Of Science
3080 - Sociology; 1020 - Physiology;
Goals / Objectives
Animal welfare issues as an important moral and practical issue for many consumers. This has encouraged public sector and industry agents to consider the humaneness and effectiveness of the techniques and technologies employed to render farmed animals insensible. Euthanasia and routine surgical procedures of livestock, such as castration and tail docking, are often cited as key practices of concern in surveys of public opinion and in video images portrayed by critics of animal agriculture. Although these procedures can be rationalized on the basis of animal welfare benefits from reduced aggression and injury, failure to provide analgesia is difficult to defend. Currently US producers and veterinarians have limited options for pain management due to paucity of approved pharmacological agents and due to practical and financial constraints for delivery of anesthesia. In Europe, carbon dioxide has been explored as an anesthetic agent for piglet castration, but concerns are raised about distress experienced during induction. Some studies suggest that argon gas may be a less aversive agent for piglet euthanasia. If so, argon may provide a more humane, safe and reliable alternative for anesthesia during routine on-farm surgeries. Furthermore, feasibility of argon gas for euthanasia of dairy calves has not been explored, and may provide an acceptable and affordable refinement for the industry to meet public expectations for animal welfare and food quality.The long-term goal of this research project is to enhance animal welfare through mitigation of pain and distress associated with induction of insensibility during gas euthanasia and anesthesia. It is our hypothesis that argon gas will provide superior and reliable induction of insensibility when compared to carbon dioxide, and that may be practically applied for on-farm euthanasia and for anesthesia or stunning of neonatal swine and calves. Specifically, this project uses an interdisciplinary approach with multistate and international collaborations to address the following objectives: 1)To explore piglet responses to exposure to and induction of insensibility with argon gas using condition place preference laboratory techniques 2)To explore the effectiveness of argon gas euthanasia when applied to pigs of compromised respiratory capacity 3)To determine the effectiveness of argon gas anesthesia for mitigating pain associated with castration and tail docking of piglets 4)To evaluate the feasibility of argon gas technology for euthanasia of morbid or unwanted neonatal calves 5)To investigate animal caretaker and public attitudes regarding acceptable euthanasia technologies for neonatal swine and calves. This project identifies practices, engineering products and processes to improve pork, dairy and veal animal systems by improving animal welfare through enhanced harvest systems. Moreover, this project refines agricultural systems to balance economic, ethical and social outcomes through investigation of public and animal caretaker attitudes about euthanasia technologies for pigs and calves.
Project Methods
Objective 1: conditioned location preference will be used to examine aversiveness of induction of insensibility using argon and CO2 gases relative to a known negative stimulus (restraint). A chamber will be constructed using plastic and Plexiglas, comprising two compartments separated by a removable door. A Plexiglas lid will facilitate video recording of behavior. Pigs will learn to discriminate compartments after associating location with exposure to argon and CO2. Pigs will subsequently avoid the compartment associated with the more aversive gas treatment. Objective 2: effects of health status on suckling nursery pig responses to gas euthanasia will be quantified with argon and CO2. Pigs will be video recorded and quantified using the Observer software (Noldus Information Technologies, Netherlands). Data will be analysed using Univariate product-limit estimation of the survival curves, to determine significant differences. Objective 3: piglets, 5-7 days of age, will be placed in a modified Euthanex chamber, gas flow rate 50% chamber exchanges/ min (argon or CO2). Thirty seconds after loss of posture, piglets will be castrated. Frequency of distress calls during surgery and post-surgical behavior in the farrowing stalls will be recorded. Blood samples (4mL) will be taken within 1-minute following surgery and plasma analysed for cortisol and substance P. Pain sensitivity tests will be performed using mechanical nociception threshold and thermal sensitivity tests. Objective 4: conditioned caretaker preference will be used to examine aversiveness of induction of insensibility using argon and CO2 gases by calves. Argon gas will be administered through a mask held to the calf's muzzle until open mouth breathing occurs, and associated with 1 of 2 caretakers. A barrier between the milk buckets will require the calf to choose to drink its milk meal in close proximity to one or the other of the two handlers at feeding time. Behavior will be video recorded and frequency and duration of contact with each handler quantified. Aversion associated with argon will be titrated relative to a known negative stimulus and to CO2. To test feasibility of gas euthanasia of dairy calves, a modified Euthanex chamber will be designed for calves. A Plexiglas lid and window will facilitate behavior observations. Objective 5: a questionnaire will be developed for livestock caregivers and for the general public to explore existing euthanasia technologies available for piglets and calves, including (1) psychosocial aspects, such as moral stress and job satisfaction, (2) ease of administration and views on the effectiveness of techniques, (3) human safety, (4) animal welfare, (5) cost/willingness to pay.

Progress 04/01/12 to 03/31/17

Outputs
Target Audience:There has been strong interest in the research associated with this project from livestock producers, industry stakeholders, veterinarians and animal protection organizations nationally and globally. Research results have been presented and professional conferences (e.g. American Society of Animal Science, AVMA Humane Endings Symposium, International Society for Applied Ethology), industry stakeholder meetings (e.g. Humane Slaughter Association, National Pork Board), regional producer extension meetings (e.g. Pork Expo). In addition, the decision to conduct animal trials on commercial operations when possible provided opportunity to rapid technology transfer and demonstration of the efficacy and animal welfare outcomes of our work at livestock caretaker and managerial levels. Changes/Problems:We requested and received a change of scope associated with Goal 4: "To evaluate the feasibility of argon gas technology for euthanasia of morbid or unwanted neonatal calves". We requested a change in species for the preference testing component of Phase 4a, from neonatal calves to neonatal goat kids. The question of aversion or distress caused by inhalant euthanasia agents, such as carbon dioxide and argon gases, is central to decision making regarding acceptability by the American Veterinary Medical Association in their Guidelines for Euthanasia (AVMA, 2014). Hence the preference/aversion testing component of Experiment 4a was of critical importance. There was no research on inhalant euthanasia agents for ruminants to our knowledge, and based on our experiences with piglet responses to carbon dioxide and argon euthanasia technologies, we anticipated several significant challenges that would affect our ability to "ask" the calves about distress and aversion associated with these gases. First, methods of administering the gases while calves are restrained, such as mask delivery to tethered calves, present risks of animal injury during the early stages when ataxia occurs. Second, the mask design for administering the gases has practical value for on-farm use, but involved significant handling and restraint components. Hence, we were concerned about likely confounding in the experimental design of the preference tests, with calf responses potentially resulting from aversion to restraint in addition to responses to gases. Third, a preference chamber for calves would be prohibitively expensive to design, and difficult to maintain gas flow in such a large space for the duration of the preference testing protocol. The preference chamber we designed for our pig experiment provided a robust experimental design to "ask" the animal about distress or aversion associated with gases without restraint/handler interference. This preference chamber accommodated neonatal goat kids, due to the similarity in size to the weaned pig. An additional benefit of using a goat model for the early ruminant euthanasia research question was immediate application of these findings. The dairy goat industry faces similar challenges to the dairy cattle industry in terms of euthanasia of compromised neonates and humane disposal of unwanted males where markets cannot be found for these animals. We were aware of producers modifying carbon dioxide equipment designed for piglet euthanasia for unwanted buck kids, although this is not a method currently approved by the AVMA. Hence, these was an immediate need by producers and by policy makers for empirical research, such as would be provided from the goat preference test experiment. We believed that results from the goat and pig preference experiments allowed for reasonable extrapolation of gas concentrations appropriate for application to the calf in Goal 4b. What opportunities for training and professional development has the project provided?This project supported training of graduate students, a technician, a postdoctoral research associate and several undergraduate and veterinary part-time student research assistantships. Training included review of the scientific literature relating to animal welfare science, experimental design, collection of behavioral data from live observations and videorecordings, handling and care of swine, goats and cattle, necropsy methods, data analysis and interpretation, preparation of technical and peer-reviewed scientific papers, presentation of research result at professional and industry meetings. This project provided partial support for Dr. Larry Sadler's doctoral dissertation, which he successfully defended in 2013. Three chapters in Sadler's dissertation relate to Goals 2 and 3 of this project. Dr. Sadler is currently employed as the Associate Director of Animal Welfare for Kraft Heinz Foods. This project provides support for Masters student Luna KC, who is expected to defend her thesis in fall 2017. Two chapters in KC's thesis relate to Goal 1 of this project. This project provided support for Masters student Isabelle Withrock, who graduated in 2015. Two chapters in Withrock's thesis relate to Goal 4a of this project. Ms. Withrock is currently a veterinary student at Kansas State University. This project provides partial support for postdoctoral researcher, Dr. Marcus McGee, who explored Goals 4B and 5. Dr. McGee is currently employed as Assistant Professor of Animal Science in the Department of Agricultural Science, Northwest Missouri State University. This project provided partial support for Research Associate Rebecca Parsons, who served as project manager, coordinating and assisting with all experiments. Ms. Parsons is currently employed as Research Associate II in the animal behavior and welfare research laboratories of Dr. Suzanne Millman (Department of Veterinary Diagnostic & Production Animal Medicine, Department of Biomedical Science) and Dr. Anna Johnson (Department of Animal Science) at Iowa State University. This project also provided support for part-time technical assistance by graduate students, veterinary students and undergraduate students. How have the results been disseminated to communities of interest?There has been strong interest in the research associated with this project from livestock producers, industry stakeholders, veterinarians and animal protection organizations nationally and globally. Research results have been presented and professional conferences (e.g. American Society of Animal Science, AVMA Humane Endings Symposium, International Society for Applied Ethology), industry stakeholder meetings (e.g. Humane Slaughter Association, National Pork Board), regional producer extension meetings (e.g. Pork Expo). In addition, the decision to conduct animal trials on commercial operations when possible provided opportunity to rapid technology transfer and demonstration of the efficacy and animal welfare outcomes of our work at livestock caretaker and managerial levels. Research findings have also been disseminated through graduate dissertations, conference proceedings, peer-reviewed articles, animal industry reports and extension factsheets. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1: A preference testing device was designed with two identical chambers separated by a sliding door and an exhaust sink. This device was utilized to examine the responses of newly weaned pigs to argon-induced hypoxic conditions and compared with responses to CO2 gas (industry standard). Pigs were individually trained for 5 consecutive days to enter the treatment chamber (TC) to interact with food rewards when the sliding door was opened, followed by 6 min during which they could move freely between the chambers. The same methods were used during the testing phase, during which CO2 in the TC was maintained at one of 3 concentrations: 10%, 20%, or 30%. Tests concluded when loss of posture (LOP) occurred or after 6 min. During each of the 3 rounds of testing, pigs experienced the assigned CO2 treatment on gas day (G), and ambient air conditions on one baseline day (B) and on one washout day (W) prior to and following G d. Behavior was collected using live observations and video recordings. Pigs remained in the treatment chamber until loss of posture occurred at 20% CO2 (5 pigs) and 30% CO2 (4 pigs). Some pigs displayed violent neuromuscular excitation before loss of consciousness occurred; for ethical reasons tests were terminated when this occurred. No pigs displayed conditioned place avoidance of the treatment chamber on any of the wash out days. Based on the results from this experiment, we concluded that proximate aversion was observed to some degree at all CO2 concentrations tested, but not sufficient to provoke marked avoidance or conditioned placed avoidance responses. Further research is needed to determine plane of anesthesia when neuromuscular excitation occurs, particularly during low CO2 concentrations expected with gradual fill methods of CO2 euthanasia. Manuscript in preparation. The same methods were used for testing pig responses to O2 displacement with argon gas (6% O2 and <2% O2 concentration). All 12 pigs entered the treatment chamber at both O2 concentrations, and 6 pigs remained in the treatment chamber until loss of consciousness occurred. Neuromuscular excitation did not occur. Pigs did not display conditioned aversion to argon based on responses during the wash out days. Based on the results from this experiment, pigs do not display proximate aversion to argon gas and hypoxia associated with argon gas is only mildly aversive to pigs. Manuscript in preparation. Objective 2: This study was conducted on commercial farms, enrolling pigs identified for euthanasia. Pigs were randomly assigned to gradual fill or prefill inhalant euthanasia involving CO2 (industry standard) or argon gases. Behavior and physiologic responses were collected by live observation and from videorecordings. Depression score in suckling pigs and respiratory disease in nursery pigs did not affect responses associated with efficacy or welfare when euthanasia was performing with C02 as the inhalant agent. Conversely, suckling pigs with high depression scores displayed longer latencies for loss of posture than pigs euthanized for other reasons when euthanasia was performed using argon as the inhalant agent. However, nursery pigs with respiratory disease lost posture faster than pigs euthanized for other reasons when euthanasia was performed using argon as the inhalant agent. Based on our results, CO2 produces more consistent and hence more reliable responses than argon when used as inhalant agents for euthanasia of pigs with compromised respiratory systems. Objective 3: Depth of anaesthesia, reliability and pig safety were assessed in association with two inhalant agents, CO2 (industry standard) and argon. Pig were paired in a euthanasia box until 30 seconds after loss of consciousness. Behavioral responses during induction and recovery were collected live and with videorecordings. Both CO2 and argon elicited signs of distressin piglets\. Results from this pilot study preclude CO2 and argon as inhalant agents for pain mitigation during piglet processing. Manuscript in preparation. Objective 4: Twelve goat kids were enrolled in the CO2 study and all kids chose to enter treatment chamber when tested at 10%, 20% and 30% CO2 concentrations. All goats remained in the treatment chamber until the milk ration was consumed or until loss of consciousness occurred. All kids lost consciousness at 20% and 30% CO2. Neuromuscular excitation was not observed. All kids entered the treatment chamber on wash out days. These results suggest CO2 is an acceptable method for euthanasia of goat kids at the concentrations tested. Manuscript in preparation. The same methods were used for testing kid responses to O2 displacement with argon gas (6% O2 and <2% O2 concentrations). All 12 kids entered the treatment chamber at both O2 concentrations, and remained in the treatment chamber until the milk ration was consumed or until loss of consciousness occurred. Fewer than half lost consciousness, and neuromuscular excitation was not observed. All kids entered the treatment chamber on wash out days, and behavior on wash out days did not differ from baseline days. These results suggest argon induced hypoxia resulted in only mild aversion, but was not reliable as a method for euthanasia of goat kids at the concentrations tested. Manuscript in preparation. Goal 4b involved evaluating the applicability of a novel mask-based CO2 gas delivery system to euthanize neonatal calves. A prototype mask was developed to deliver inhalant agents for euthanasia to the calf at specified concentrations, using an open circuit breathing apparatus. In the preliminary trials to refine the mask design and protocol, responses of 3 neonatal dairy bull calves (0-7 days of age) were observed during exposure to CO2. Behavioral responses were recorded using live observations and videorecordings. Calves showed little distress during acclimatization, and loss of posture occurred following ataxia with little struggle and few vocalizations. However, none of the calves progressed to loss of consciousness and displayed a degree of alertness for 4 minutes following CO2 exposure. Based on our results, the mask prototype was tolerated by the calves and successfully delivered 25% CO2. However, target gas concentration was not maintained consistently over time perhaps due to positional changes of the muzzle within the mask. Calves appear to tolerate 25% CO2, but this concentration resulted in an unacceptably prolonged period of induction. Further basic research in needed to clarify calf physiologic responses to CO2 before further development of the calf mask-based gas delivery system. Technical report in preparation. Objective 5: An observational study was performed to better understand swine caretaker attitudes and opinions about euthanasia methods in swine production A questionnaire was developed for swine caretakers to document the following: (1) psychosocial aspects, such as moral stress and job satisfaction associated with euthanasia, (2) current use of euthanasia techniques and (3) views on animal welfare. Surveys were mailed between December 2014 and June 2015 to caretakers associated with 4 swine production companies in 8 states. Manuscript in preparation. The research team is exploring opportunities to apply the survey tool to bovine caretakers and to the non-farming citizens.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Millman ST, 2017. Contributions and constraints of animal welfare science for on-farm euthanasia decisions. CAWS Advancing Animal Welfare Science: Overcoming Obstacles to Implementation, Purdue University, West Lafayette, IN, May 18, 2017. Invited plenary presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Millman, ST, 2016. Euthanasia best practices. SowBridge Webinar, May 4, 2016.
  • Type: Other Status: Published Year Published: 2016 Citation: Millman ST, 2016. Animal welfare science & policy  the use of inhalant agents for euthanasia of livestock. Animal Welfare Science and Bioethics Centre, Massey University, Palmerston North, New Zealand, June 10, 2016. Oral presentation.
  • Type: Other Status: Published Year Published: 2015 Citation: Millman ST, 2015. Euthanasia of piglets  alternatives to manually applied blunt force trauma. Niman Ranch Annual General Meeting, Ames, IA. Oral presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Millman, S.T., 2014. Taking the animals perspective. Designing experiments to ask animals about their feelings and preferences. CVM Research Day, Iowa State University, Ames, IA, Jan. 8, 2014. Oral presentation.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Millman ST, Withrock IC, KC L, Johnson AK, Sutherland MA, 2015. Assessment of aversion to carbon dioxide by weaned pigs and neonatal goats. Human Slaughter Association (HSA) International Symposium 2015: Recent advances II. Zagreb Croatia 16th  17th July 2015. Oral presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: KC L, Johnson AK, Karriker LA, Shepherd TA, Stinn JP, Xin H, Sutherland MA, Lay DC, Millman ST, 2015. Assessment of aversion to different concentrations of CO2 gas by weaned pigs using an approach-avoidance paradigm. USDA Project Directors Annual Meeting, Chicago, IL, Dec. 4, 2015. Poster.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: KC L, Johnson AK, Karriker LA, Shepherd TA, Stinn JP, Xin H, Sutherland MA, Lay DC, Millman ST, 2015. Assessment of aversion to different concentrations of CO2 gas by weaned pigs using an approach-avoidance paradigm. Humane Slaughter Association (HSA) International Symposium 2015: Recent advances II. Zagreb Croatia 16th  17th July 2015. Poster
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Withrock IC, Plummer PJ, Shepherd TA, Stinn JP, Xin H, Johnson AK, Sutherland MA, Millman ST, 2015. Tolerance of carbon dioxide gas by neonatal goats. Humane Slaughter Association (HSA) International Symposium 2015: Recent advances II. Zagreb Croatia 16th  17th July 2015. Poster
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Millman ST, Withrock I, Plummer P, Johnson A, Xin H, 2014. Responses of neonatal goats (kids) to different concentrations of carbon dioxide gas. AVMA Humane Ending Symposium, Rosemont, IL, Nov. 3-5, 2014. Oral presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Withrock I, Plummer P, Shepherd T, Stinn J, Johnson A, Xin H, Coetzee J, Millman S, 2015. Assessment of cognitive ability and memory retention in neonatal goats. ASAS-ADSA Joint Annual Meeting, July 12-16, 2015, Orlando, FL, USA. Oral presentation #727.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Withrock IC, Plummer PJ, Shepherd TA, Johnson AK, Xin H, Coetzee JF, Millman ST, 2015. Responses of neonatal goats (kids) to different concentrations of carbon dioxide gas. ASAS-ADSA Joint Annual Meeting, July 12-16, 2015, Orlando, FL, USA. Poster #M140.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Millman ST, 2014. Responses of neonatal goats (kids) to different concentrations of carbon dioxide gas. USDA AFRI Project Director (Virtual) Meeting, Nov. 19-21, 2014. Online oral presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: KC L, Johnson AK, Shepherd TA, Stinn JP, Xin H, Stalder KJ, Karriker LA, Sutherland MA, Lay Jr. DC, Millman ST, 2016. Aversion to CO2 gas in pigs using approach-avoidance and conditioned place avoidance paradigms. ASAS Midwestern Section and ADSA Midwest Branch, Scientific Sessions and Business Meeting, Des Moines, IA, Mar. 12-16, 2016. Oral presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: McGee M, Parsons R, OConnor A, Johnson A, Anthony R, Ramirez A, Millman S, 2016. A preliminary examination of swine caretakers perspectives for euthanasia technology and training. ASAS/ADSA/CSAS Joint Annual Meeting, Salt Lake City, UT.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: 1. Sadler LJ, Karriker LA, Schwartz KJ, Johnson AK, Widowski TM, Wang C, Sutherland MA, Millman ST, 2014. Are severely depressed neonatal pigs resistant to gas euthanasia? College of Veterinary Medicine Faculty Research Day, Iowa State University, Jan. 8., 2014. Poster
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Sadler LJ, Widowski TM, Wang C, Johnson AK, Millman ST, 2012. Argon versus CO2 gas induction of unconsciousness in piglets. Proceedings of the 2012 JAM Joint Annual Meeting, Phoenix, AZ, July 15-19, 2012. J. Anim. Sci Vol. 90, Suppl.3/J Dairy Sci Vol. 95 Suppl.2, Oral abstract 821, p.723
  • Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: Withrock IC, 2015. The use of carbon dioxide (CO2) as an alternative euthanasia method for goat kids. Graduate Theses and Dissertations. Paper 15718. Iowa State University, Ames, IA, USA.


Progress 04/01/13 to 03/31/14

Outputs
Target Audience: These results have been incorporated into the Iowa Swine Welfare School euthanasia training module, which is currently offered by Iowa State University College of Veterinary Medicine and Agriculture Extension. Research results have been communicated to Sherrie Niekamp, Director of Animal Welfare, National Pork Board, with reference to suggested revisions to the Guidelines for Euthanasia recommendations. We will submit an abstract for consideration to the AVMA Humane Endpoints conference planned for November 2014. Changes/Problems: 1) There was a delay in initiation of Goal 1 due to enrollment of a graduate student with interest in this component of the project. Luna KC enrolled as a doctoral student in Fall 2013 and has initiated the animal trials associated with Goal 1. We anticipate completion of Goal 1 experiments in Fall 2014, with publications and presentations released in early 2015. 2) We requested and received a change of scope associated with Goal 4: “To evaluate the feasibility of argon gas technology for euthanasia of morbid or unwanted neonatal calves”. We requested a change in species for the preference testing component of Phase 4a, from neonatal calves to neonatal goat kids. The question of aversion or distress caused by inhalant euthanasia agents, such as carbon dioxide and argon gases, is central to decision making regarding acceptability by the American Veterinary Medical Association in their Guidelines for Euthanasia (AVMA, 2014). Hence the preference/aversion testing component of Experiment 4a is of critical importance. There has been no research on inhalant euthanasia agents for ruminants to our knowledge, and based on our experiences with piglet responses to carbon dioxide and argon euthanasia technologies, we anticipated several significant challenges that would affect our ability to “ask” the calves about distress and aversion associated with these gases. First, methods of administering the gases while calves are restrained, such as mask delivery to tethered calves, presents risks of animal injury during the early stages when ataxia occurs. Second, the mask design for administering the gases has practical value for on-farm use, but involves significant handling and restraint components. Hence, there is likely to be confounding in the experimental design of the preference tests, with calf responses potentially resulting from aversion to restraint in addition to responses to gases. Third, a preference chamber for calves would be prohibitively expensive to design, and difficult to maintain gas flow in such a large space for the duration of the preference testing protocol. The preference chamber we designed for our pig experiment provides a robust experimental design to “ask” the animal about distress or aversion associated with gases without restraint/handler interference. This preference chamber could accommodate neonatal goat kids, due to the similarity in size to the weaned pig. An additional benefit of using a goat model for the early ruminant euthanasia research question is immediate application of these findings. The dairy goat industry faces similar challenges to the dairy cattle industry in terms of euthanasia of compromised neonates and humane disposal of unwanted males where markets cannot be found for these animals. We have heard of producers modifying carbon dioxide equipment designed for piglet euthanasia for unwanted buck kids, although this is not a method currently approved by the AVMA. Hence, there is an immediate need by producers and by policy makers for empirical research, such as would be provided from the goat preference test experiment. We believe that results from the goat and pig preference experiments allow for reasonable extrapolation of gas concentrations appropriate for application to the calf in Goal 4b – the feasibility study in 2015. What opportunities for training and professional development has the project provided? This project provided partial support for Dr. Larry Sadler’s doctoral dissertation, which he successfully defended in 2013. Two chapters in Sadler’s dissertation relate to Goal 2 for this project. Sadler is currently employed as the Associate Director of Animal Welfare for Kraft Foods, Madison, WI. This project provides support for doctoral student Luna KC, who is currently exploring Goal 1, measuring piglet aversion associated with induction of insensibility with argon and carbon dioxide gases. She will apply her findings from this component of the project to Goal 3, exploring inhalant anesthesia for mitigating pain associated with piglet castration and tail docking. This project provides full support for Masters student Isabelle Withrock, who is currently exploring Goal 4a, measuring goat kid aversion associated with induction of insensibility with argon and carbon dioxide gases. This project provides partial support for doctoral student, Kathleen Tapper, who is currently exploring Goal 5 – attitudes of swine caretakers to euthanasia technologies. This project provide partial support for Research Associate Rebecca Parsons, who serves as project manager, coordinating and assisting with all experiments. This project also provide support for technical assistance by graduate students (Kara Fiedler, Jessie Colpoys), veterinary students (Lauren Larsen, Lourdes Maldonaldo, Stephen Ball, Kassi Miller) and undergraduate students (Kesley Aardsvold), Natalie White, Chris Byrd). How have the results been disseminated to communities of interest? Results have been communicated to swine producers, veterinarians and agriculture extension agents through our Iowa State University Swine Welfare School euthanasia training modules. A factsheet on alternatives to manually applied blunt force trauma has been submitted to the Pig Information Gateway extension effort in June 2014. Copies of the research publications arising from Goal 2 (Sadler et al., 2014a, 2014b) were sent to swine producers, including farms participating in experiments associated with Goal 2 (Murphy Brown LLC, the largest swine producer in the US, and Elite Pork Products of Carroll, IA), as well as to producers and veterinarians who requested these documents. A plenary lecture on gas euthanasia of pigs was provided by doctoral candidate Larry Sadler at the International Congress of the International Society for Applied Ethology in June 2013, and Suzanne Millman presented a plenary including components of this research project at a conference in Chongqing, China in October 2013. What do you plan to do during the next reporting period to accomplish the goals? Third year of the project will see the completion of Goal 1 (operant techniques to compare piglet aversion to CO2 and argon gases), and Goal 4a (operant techniques to compare neonatal ruminant aversion to CO2 and argon gases). The survey tool for evaluating caregiver attitudes about euthanasia technologies for swine has been developed, and will be launched in summer 2014. We anticipate completion of the swine component of Goal 5 during year 3, which will inform the development of surveys for the calf and public components of Goal 5. In the third year of the project we anticipate submission of conference abstracts and journal manuscripts associated with Goal 1 and 2 manuscripts associated with Goal 4a for the argon and carbon dioxide trials. Submissions will be targeted to journals and conferences with international scope in animal science, veterinary science, and animal welfare. We will present our findings at the NIFA annual meeting. We also anticipate publication of relevant Animal Industry Reports from Iowa State University to target producers and extension agents.

Impacts
What was accomplished under these goals? 1) Depression score in suckling pigs and respiratory disease in nursery pigs did not affect responses associated with efficacy or welfare when carbon dioxide was used. Conversely, with argon suckling pigs with high depression scores displayed longer latencies for loss of posture than pigs euthanized for other reasons and nursery pigs with respiratory disease lost posture faster than pigs euthanized for other reasons. Regardless of application method, including all methods tested with carbon dioxide, distress is still observed therefore, ingenuity and research are still needed to identify practical on-farm euthanasia methods that will further reduce pig distress. 2) A unique preference-testing box has been designed for testing animal responses to atmospheres with different carbon dioxide and oxygen concentrations (Goal 1a). The box is comprised of a doorway facilitating free movement of the test animal between two chambers. Dynamic gas flow, recovery and sensor systems allow us to maintain carbon dioxide gas concentrations at specific levels within the test chamber, while maintaining ambient air conditions within the start chamber. Carbon dioxide gas concentrations of up 25% can be maintained in the treatment chamber for 10 minutes while carbon dioxide concentrations in the start chamber are maintained at 1%, consistent with OSHA standards. 3) Preliminary results from preference test experiments (Goal 4a) indicate that neonatal goat kids learn to enter the test chamber to access their milk ration, and preference for the test chamber is displayed for 10 minutes while the milk ration is consumed, and this preference is not affected by te presence of a novel odor (peppermint). Goat kids choose to enter and remain in the test chamber when tested at 10% and 20% carbon dioxide levels. Mild ataxia is induced when goat kids are exposed to 10% carbon dioxide for 10 minutes. Goat kids willingly enter a test chamber with 20% carbon dioxide and do not choose to leave the chamber, displaying ataxia and then loss of posture within several minutes of exposure. All goat kids willingly entered the test chamber when tested on subsequent days, suggesting carbon dioxide gas concentration of 20% or less are not aversive to the neonatal goat.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Millman, S.T., 2013. Project summary: An examination of argon gas for on-farm anesthesia and euthanasia of livestock. 2013 Animal Health & Animal Well-being USDA NIFA Agriculture and Food Research Initiative Project Director Workshop., University of Maryland, Oct. 6-8, 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Millman, S.T., 2013. Research on humane euthanasia of swine. Proceedings of the 2013 International Symposium on Animal Environment and Welfare, Rongchang, Chongqing, Oct. 19-21, 2013.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Sadler LJ, Karriker LA, Johnson AK, Schwartz KJ, Widowski TM, Wang C, Millman ST, 2014. Swine respiratory disease minimally affects responses of nursery pigs to gas euthanasia. Journal of Swine Health and Production 22(3):125-133.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Sadler LJ, Karriker LA, Schwartz KJ, Johnson AK, Widowski TM, Wang C, Sutherland MA, Millman ST, 2014. Are severely depressed suckling pigs resistant to gas euthanasia? Animal Welfare 23:145-155
  • Type: Theses/Dissertations Status: Under Review Year Published: 2013 Citation: Sadler LJ, 2013. Effect of flow rate, gas type and disease status on the welfare of neonate and sucking pigs during gas euthanasia. Iowa State University, Ames, IA, USA. Doctoral dissertation.


Progress 04/01/12 to 03/31/13

Outputs
Target Audience: Animal trials were conducted on 2 commercial swine facilities in MO. During the experiments, animal caretakers employed by the farm had the opportunity to learn about the scientific basis for the studies of argon and carbon dioxide gas as euthanizing agents, scientific techniques to assess animal welfare and confirm death. We also provided a seminar on best practices for swine euthanasia and the research study for the farm staff in Nevada, MO, and assessment of the company's euthanasia equipment and standard operating procedures. We also provided a White Paper presentation to at the Murphy Brown Western Division headquarters in Ames, IA to update the senior management about the findings from the study and our general recomemndations for gas euthanasia standard operating procedures. Research results from the animal trials completed (Experiment 2) were communicated to Sherrie Niekamp, Director of Animal Welfare, National Pork Board, with reference to suggested revisions to the Guidelines for Euthanasia recommendations.These results are also being incorporated into the Iowa Swine Welfare School euthanasia training module. Research results from Experiment 2 were communicated in an oral presentation and publication at the Swine Diseases Conference, Ames, IA in November 2012. (see publications section) Changes/Problems: This research project was submitted with a proposed start date of 2011. Since there was a delay in the review and awarding of NIFA grants during that round of proposals, the award was not received until April 2012. Doctoral candidate Larry Sadler had been previously identified for this project, and since he was near completion of his program, he only had time available to explore one Goal. He chose Goal 2 as fitting most closely with the theme of his dissertation. Hence, there was a delay in initiation of Goal 1. We anticipate the timeline for animal trials will be back on track after Year 2 with the addition of veterinarian Luna KC as a new doctoral student and animal scientist Isabelle Withrock as a new Masters student. Both prospective students are excited to have the opportunity to develop their skills in operant techniques to test aversion and motivation. Research associate Rebecca Parsons has developed sufficient skills in gas technologies and euthanasia techniques to full step into her role as project manager when Larry Sadler graduates. Hence, the animal welfare laboratpry team is expanding and increasingly skilled to respond to the research questions in this project. What opportunities for training and professional development has the project provided? Goal 2 provided 2 chapters in Larry Sadler's doctoral dissertation, and were the basis for his invitation to present our results in a plenary session of the primary international conference for the discipline of applied ethology. One Masters student, Kara Fiedler, was partly supported by this project, and assisted with Goal 2. 3 part-time veterinary professional students (Lauren Larsen, Lourdes Maldonaldo and Stephen Ball) were supported by this project and provided technical assistance for Goal 2 2 undergraduate students (Natalie White and Chris Byrd) were supported by this project and provided technical assistance for Goal 2. Research associate Rebecca Parsons had opportunity to develop her technical skills in swine clinical procedures, science of euthanasia technologies, and agricultural engineering techniques for measuring and controlling gas concentrations associated with euthansia during her contributions to the project. 1 PhD student and 1 MS student have been identified and accepted for Fall 2013 enrollment into the Biomedical Sciences program. These students will work on Goals 1, 3 nd 4 during the second year of the project. How have the results been disseminated to communities of interest? The results from Goal 2 were communicated to researchers, students and policy makers attending the International Congress of the International Society for Applied Ethology. Results from Goal 2 were communicated to National Pork Board and American Association of Swine Veterinarians for suggested revisions to the Recommended Guidelines for Euthanasia and training CD. These results are currently being incoorporated into the euthanasia module of the Iowa Swine Welfare School, with a training session and launch of the second edition module for extension agents and faculty scheduled for Dec. 13, 2013. Results from Goal 2 were communicated to swine producers and veterinarians collaborating on our euthanasia research projects as soon as they became known, and have been incorporated into management decisions about euthanasia protocols. These farms include Murphy Brown LLC, which is the largest swine producer in the US, Elite Pork Products of Carroll, IA and the Iowa Pork Producers Association Swine Well-being Committee. What do you plan to do during the next reporting period to accomplish the goals? The second year of the project will focus on Goal 1 (operant techniques to compare piglet aversion to CO2 and argon gases), and Goal 3 (operant techniques to compare calf aversion to CO2 and argon gases). We also anticipate initial development of the euthanasia survey tool, and associated ethical approval for its application to human subjects (Goal 5). In the second year of the project we also anticipate publication of 2 manuscripts associated with Goal 2. Draft manuscripts comprise 2 chapters in Larry Sadler's doctorla dissertation, and will be submitted to Journal of Swine Health and Production for a veterinary practitioner target audience, and to Animal Welfare for an international audience of animal welfare researchers, educators, policymakers and non-governmental organizations. We also anticipate publication of 2 Animal Industry Reports from Iowa State University to target producers and extension agents. The second revision of the Iowa Swine Welfare School euthanasia module will be developed and launched during the second year of this project, and will incorporate findings from this project (goal 2, and preliminary findings from Goal 1 if available). This module will provide livestock extension agents and faculty with the latest information about swine euthanasia techniques, a test of comprehension and wet lab to confirm competence. The extension team will provide greater outreach for euthanasia training to swine producers.

Impacts
What was accomplished under these goals? Goal 2 was completed during this first year of the project, and results published in a doctoral dissertation by Larry Sadler (examination date July 15, 2013). Depression score in suckling pigs and respiratory disease in nursery pigs did not affect responses associated with efficacy or welfare when carbon dioxide was used. Conversely, with argon suckling pigs with high depression scores displayed longer latencies for loss of posture than pigs euthanized for other reasons and nursery pigs with respiratory disease lost posture faster than pigs euthanized for other reasons. Regardless of application method, including all methods tested with carbon dioxide, distress is still observed therefore, ingenuity and research are still needed to indentify practical on-farm euthanasia methods that will further reduce pig distress.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Sadler L, Millman ST, 2012. Advances in gas euthanasia techniques and equipment. Proceedings of the ISU Swine Diseases Conference for Practitioners, November 2012, Ames, IA, p.94-98.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Sadler L, Karriker L, Johnson A, Wang C, Widowski T, Millman S, 2013. Effects of depression score on welfare implications of CO2 and argon gas euthanasia of piglets. Plenary Presentation #5. Proceedings of the 47th International Congress of the International Society for Applied Ethology, Florianopolis, Brazil, p.44.
  • Type: Theses/Dissertations Status: Under Review Year Published: 2013 Citation: Sadler LJ, submitted. Effect of flow rate, gas type and disease status on the welfare of neonate and sucking pigs during gas euthanasia. Doctoral Dissertation, Department of Biomedical Sciences, Iowa State University.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Millman S, Johnson A, Karriker L, Shearer J, Dewell G, Dewell R, Xin H, O'Connor A, Sutherland M, Coetzee J, Anthony R, Hagen C, Rademacher C, Niekamp S, 2012. An examination of argon gas for on-farm anesthesia and euthanasia of livestock. USDA NIFA Animal Health and Welfare Project Director Meeting, Chicago, IL, Dec. 1, 2012.