December 2014 // Volume 52 // Number 6 // Feature // v52-6a5
Bio-Security Proficiencies Project for Beginning Producers in 4-H
Improving bio-security practices among 4-H members who raise and show project animals is important. Bio-security measures can reduce the risk of disease spread and mitigate potential health and economic risks of disease outbreaks involving animal and zoonotic pathogens. Survey data provided statistical evidence that the Bio-Security Proficiencies Project for Beginning Producers in 4-H advanced youth participants' knowledge and skills related to bio-security and financial risk management. Furthermore, the project provided youth with opportunities to apply their understanding and abilities to authentic settings and extend their learning to their communities.
Bio-security can be defined as "a series of management procedures designed to prevent or greatly reduce the risk of introducing new infectious agents to a farm" (California Department of Food and Agriculture [CDFA], 2014). Common bio-security practices for animal agriculture include quarantine procedures for new animals or animals that show signs or symptoms of disease; disinfecting stalls and equipment; reducing or eliminating contact with other animal species; and the management of housing, travel, and visitors (e.g., veterinarians, livestock haulers, and nutritionists) (Animal and Plant Health Inspection Service [APHIS], 2012; CDFA, 2014).
Research data have shown that a large-scale disease outbreak in the United States would have significant adverse economic impacts on commercial animal agriculture (Paarlberg, Seitzinger, Lee, & Mathews, 2008; Pedersen et al., 2004). Despite the fact that systematic and consistent bio-security among commercial animal agriculture operations is essential, management practices are mixed, which increases susceptibility to disease incursion (Anderson, 2010; APHIS, 2012; Brandt, Sanderson, DeGroot, Thomson, & Hollis, 2008; Caraviello et al., 2006). One potential source of pathogens that can threaten large-scale animal agriculture is animals raised on backyard farms that come into contact with commercial herds and flocks (Food and Agriculture Organization of the United Nations, 1999; Nolen, 2003; World Health Organization, 2011). Thus, improved bio-security practices among backyard producers are essential.
Most 4-H Animal Science project animals can be considered of the backyard variety, and there is evidence of the need for improved bio-security practices among 4-H youth. An online survey of 252 4-H youth members from 40 California counties showed that 66% of project animals were housed in backyard herds of approximately 8-9 animals of the same or mixed species and that these animals were transported to an average of two 4-H club meetings each year where mixing with other animals occurred (Smith, 2009). In the context of club meetings with their animals present, 19% of the survey respondents reported applying no bio-security measures, and only 2% of youth respondents reported the use of extensive bio-security practices, including use of hand sanitizers, isolating animals, disinfecting footwear, and not using shared equipment (Smith, 2009). With respect to monitoring their animals for signs and symptoms of disease (early intervention), 25% of the youth who completed the survey reported never performing health checks on their project animals (Smith, 2009).
Survey data also revealed that 4-H youth showed their animals at an average of 2.5 public venues annually within and beyond their home counties (Smith, 2009). Animals exhibited at fairs and shows represent bio-security risks through additional animal-to-animal contacts and the possibility of disease transmission through other modes (e.g., indirect contact, airborne transmission, fecal-oral). Specifically, pathogens that cause animal diseases such as malignant catharral fever (e.g., Moore et al., 2010), as well as zoonotic illnesses (diseases transmissible between humans and animals) caused by enteric pathogens such as E. coli and Campylobacter and strains of the Avian Influenza virus, have been shown to be transmissible at public venues (e.g., Olson & Gray, 2006; Keen, Wittum, Dunn, Bono, & Durso, 2006; Roug, Byrne, Conrad, & Miller, 2012; Steinmuller, Demma, Bender, Eidson, & Angulo, 2006). Data collected at the California State Fair and eight county fairs in the north central region of California revealed specific bio-security transmission risks associated with exhibition practices involving 4-H animals, including issues related to housing, wash racks, judging arenas, and visitor contact (Smith & Meehan, 2012).
These risks highlight the need to provide effective bio-security education in 4-H. Thus, the current study focused on the implementation and evaluation of the Bio-Security Proficiencies Project for Beginning Producers in 4-H in three California counties. At the heart of the project were well-designed educational activities that emphasized the concepts of disease transmission, risk assessment, risk mitigation, and financial risk management through experiential learning and engaged youth in the application of knowledge and skills to authentic situations. Specifically, activities were organized into five proficiency levels (Figure 1) that advanced youth participants' learning over time.
4-H staff recruited adult volunteers to implement the Bio-Security Proficiencies Project for Beginning Producers in 4-H with youth members in three counties. Recruitment strategies included presentations at 4-H meetings, information sessions held at 4-H county offices, and phone and e-mail contact. All participating 4-H volunteers (n=15) had prior experience leading Animal Science projects with youth members. Youth participants (n=120), members of 4-H clubs in their respective counties, were between the ages of 8 and 17, with the average age being 13.
Professional development for participating 4-H volunteers followed a modified version of the Step-Up Incremental Training Model (Smith & Enfield, 2002) that included face-to-face workshops and conference calls coupled with online technology. In particular, volunteers participated in an initial on-site professional development workshop with project staff where they engaged directly in the activities and procedures necessary for the implementation of Proficiency 1. The workshop focused on subject matter content, the use of effective pedagogy, including guided inquiry and questioning strategies, and the application of knowledge and skills in real-world situations.
Two subsequent professional development workshops for participating 4-H volunteers were held using teleconference and Web-conferencing technologies. These workshops included a review of all project materials and recommended implementation strategies for subsequent proficiency levels. Specifically, the second workshop focused on activities and procedures necessary for the implementation of Proficiency 2; the third workshop involved preparation for the implementation of Proficiencies 3, 4, and 5. This incremental approach has shown to be beneficial in that it provides participating volunteers time to reflect on previous implementations with youth participants, thus allowing them the opportunity to share challenges they encountered, as well as strategies they found to be effective (Smith & Enfield, 2002).
The five-levels of bio-security proficiency were designed to build 4-H youths' knowledge and skills over time. Specifically, the implementation of the proficiencies occurred with 4-H youth following the sequences outlined in Figure 1. The numbered items shown in plain font indicate work completed by youth participants in a group setting (e.g., 4-H club); the numbered items shown in italics represent work completed by youth independently. Authentic assessments were built into the independent work associated with each proficiency level in the form of activities that required written tasks, the application of skills, and photo documentation. Specific examples included: keeping a daily animal health journal for two weeks; a bio-security risk assessment of 4-H members' home premises; the planning and execution of a bio-security risk mitigation plan for 4-H youth members' home premises; the development and delivery of a public presentation on bio-security; and the application of best practices at a public venue. Completion of these activities was required to attain proficiency at each level. Youth who completed the necessary requirements were awarded a pin and certificate for each proficiency level they achieved.
Bio-Security Proficiency Level 1
Bio-Security Proficiency Level 2
Bio-Security Proficiency Level 3
Bio-Security Proficiency Level 4
Bio-Security Proficiency Level 5*
|*Note: Bio-Security Proficiency 5 was optional for this study.|
Three forms of data collection were approved by the Institutional Review Board (IRB) Administration through the University of California's Office of Research and conducted over the course of the Bio-Security Proficiencies Project for Beginning Producers in 4-H.
- Surveys that measured changes in knowledge and skills were administered following each Proficiency Level. These surveys were designed using a retrospective (post-as-pre) format for the purpose of reducing response-shift bias, a threat to internal validity that can arise when using a pre/post survey design (Raidl et al., 2004). Specifically, surveys included five sets of paired questions, each with four response categories ranging from "Poor" to "Excellent." Four response categories were utilized to help ensure discriminating answers by participants and eliminate the potential misinterpretation of a mid-point (Croasmun & Ostrom, 2011). Question 1 asked about the youth's current level of knowledge or skills relative to a specific topic after the educational intervention (post); question 2 asked about the youth's level of knowledge or skills relative to the same topic prior to the educational intervention (pre). A sample set of paired questions from one retrospective survey is shown in Figure 2.
- As part of Proficiency Level 2, youth participants were required to complete a risk assessment of their home premises. The frequency that specific risks were reported across all participants was recorded.
- Surveys were administered to adults who attended public presentations delivered by youth as part of Proficiency Level 4. These surveys collected basic information about the attendees' roles and experience with animal agriculture. A retrospective (post-as-pre) format was utilized to determine changes in knowledge relative to bio-security concepts.
|Question 1||Question 2|
My understanding of the critical control points for disease transmission is:
1. Poor; 2. Fair; 3. Good; 4. Excellent
Before participating in this activity
my understanding of the critical control points for disease transmission was:
1. Poor; 2. Fair; 3. Good; 4. Excellent
Survey data (youth and adults) were analyzed using paired t-tests to determine change in scores (Poor = 1 to Excellent = 4) between their pre- and post-intervention levels of knowledge and skills. Data analysis was executed using Minitab 16 statistical software (2010).
All 120 4-H youth who enrolled in the Bio-Security Proficiencies Project for Beginning Producers in California 4-H completed Proficiency Level 1; 104 youth (87%) completed levels 1 and 2; 86 (72%) accomplished levels 1, 2, and 3; and 63 (52%) accomplished proficiency levels 1, 2, 3, and 4 (Table 1). Additionally, 32 youth (26%) completed Proficiency Level 5, the optional component in this investigation (Table 1).
|Proficiency Level||Number of Participants||Number Surveyed**|
|Proficiency 1||120 youth||54|
|Proficiency 2||104 youth||50|
|Proficiency 3||86 youth||25|
|Proficiency 4||63 youth||23|
|Proficiency 5 (optional)||32 youth||Not Applicable|
|**Participants were not required to complete post-proficiency surveys as per IRB Human Subjects Protocol.|
Youth Survey Results
Scores on the retrospective surveys improved significantly at all Proficiency Levels. Changes in mean scores for paired sets of questions for each proficiency level (1-4) were calculated by comparing pre- and post-intervention mean scores for each survey. Mean scores are reported in Table 2. All improvements in mean scores reported were significant at p < 0.001.
|Proficiency Level||Bio-Security Concepts||Pre Mean||Post Mean|
|1||Modes of disease transmission; making health observations; keeping health records||2.05||2.91|
|2||Critical control points; roles of vectors and vermin; assessment of bio-security risks||2.08||3.16|
|3||Identifying financial risks; cost-benefit analysis||2.15||3.10|
|4||Bio-security risk reduction planning and implementation; communicating with public||1.81||3.31|
Bio-Security Risks Identified on Home Premises
Using the Bio-Security Risk Assessment Tool (Smith, Meehan, et al., 2009), participating youth completed an analysis of their home premises and identified areas of low, moderate, and high risk. The risks they identified were organized into five main categories:
- Transportation-related (e.g., transportation with other animals; cleanliness of trailers/vehicles).
- Animal-related risks (e.g., quarantine practice; vaccination status; contact with wildlife).
- Human-related (e.g., contact with visitors; use of appropriate clothing and footwear; hand-washing practices).
- Food- and water-related (e.g., quantity and quality of food and water; access to food and water).
- Housing-related (e.g., stocking density; cleanliness; vermin and vector control; sanitation of tools; sharing of tools; ventilation and climate).
A total of 110 risks at the moderate or high level were identified. Figure 3 displays the distribution of risks identified across the five categories described.
Frequency of Bio-Security Risks
Frequency of bio-security risks identified by participating 4-H youth on their home premises.
Adult Community Member Survey Results
As a requirement for completing Proficiency Level 4, youth developed and delivered public presentations on bio-security for families and community members. Six different presentations were delivered between the three participating counties. A total of 140 adult community members attended. Attendees included parents of 4-H participants, local government representatives, 4-H staff, fair board members, and representatives from agricultural associations (e.g., California Farm Bureau Federation; California Cattlemen's Association). Forty-one percent of the individuals in attendance reported that they were active in animal agriculture, either as producers or hobbyists.
All adult attendees were asked to answer an optional survey following the presentations by 4-H youth. Sixty-three surveys were completed. Survey results showed significant (p < 0.05) improvements in attendees' understanding of the modes of disease transmission, the role of critical control points in disease spread, and financial risks related to bio-security practices among young producers. Finally, of those attendees who identified themselves as active in animal agriculture, 95% reported that the information presented by the youth was directly applicable to their practice.
Proficiency Level 5
Proficiency Level 5, where youth were asked to assume the responsibility of planning and executing a bio-security-related service-learning project in collaboration with their county fair, was optional for this investigation. However, the youth participants (32) from one county elected to participate in this proficiency. The 4-H youth members worked collaboratively with the Chief Executive Officer of their county fair to address bio-security issues they identified as important. Specifically, all pens, tie stalls, wash racks, and scales were cleaned and disinfected. In addition, laminated signs with information about bio-security practices were posted in all barns, and participating 4-H youth spoke with fair attendees and other 4-H youth regarding bio-security practices. In particular, youth conveyed information about specific diseases these bio-security practices were targeting, including sore mouth, a zoonotic viral disease of sheep and goats (Leite-Browning, 2008) that had been a problem at the county fair in previous years.
Approximately 34,000 youth participate in 4-H Animal Science projects annually in California; nationally, this number exceeds 1,866,000 (USDA, 2011). The majority of these projects focus on the rearing, care, husbandry and, in many cases, showing and marketing of live animals, including poultry, ruminants, and swine. In most cases, 4-H members house their animals at home or on local farms, meet collectively as a club once or more monthly, and convene in larger groups on exhibition days and at county or state fairs. As such, these projects have the potential to be associated with animal or zoonotic disease outbreaks (Amass, Schneider, & Kenyon, 2004). In addition, research indicates that these risks are particularly present in fair and exhibition settings. For example, Rough, Byrne, Conrad, & Miller (2012) demonstrated the presence of fecal-borne zoonotic pathogens among livestock exhibited at a county fair in California. In another study, Keen, Wittum, Dunn, Bono, & Durso (2006) found that of 2,919 fecal specimens from 29 county fairs in two states and at three state fairs, 186 (6.4%) were positive for E. coli 0157, an enteric zoonotic pathogen. Furthermore, these researchers collected four samples from fair grounds 10-11 months following the fairs when no animals were present and found them to be positive for E. coli 0157, indicating that this pathogen remains in the environment for extended periods of time.
The scale of the national 4-H Animal Science Program, evidence of insufficient on-farm and at-fair practices to reduce the transmission of pathogens, and the potential of animal or zoonotic disease outbreaks underscore the need for systematic dissemination of bio-security education among 4-H youth who raise project animals (Smith, 2009; Smith & Meehan, 2012). Developing good bio-security practices among 4-H members who raise and show animals can help mitigate potential animal disease outbreaks involving animals within backyard flocks and herds, with backyard animals that come into contact with commercial growers, and among animals exhibited at public venues. Best practices can also help protect human health by decreasing the likelihood of the spread of zoonotic pathogens. Furthermore, the monetary investment by 4-H youth who raise 4-H project animals is not insignificant (e.g., Harrison & Eborn, 2012; Kirkpatrick & Neel, n.d.), and improved bio-security can help reduce potential adverse financial risks, including the potential loss of animal life, disruption in production, or costly disease recovery.
Recommendations on bio-security practices are available to 4-H youth in published form from numerous private, state, and national sources, including commodity groups (e.g., American Sheep Industry Association, 2014), university Extension services (e.g., Leite-Browning, Browning, Vaughn, Andries, & Simon, 2011), state departments of agriculture (e.g., CDFA, 2014), and the United States Department of Agriculture (USDA) (e.g., USDA, 2012). However, the vast majority of these publications lack specific suggestions regarding conducting on-farm risk assessments, and few provide tools necessary to carry out a risk assessment (Moore et al., 2007). Moore et al. (2007) stress the importance of engaging producers in on-farm risk assessments as a strategy that can help serve as a motivation to adopt bio-security practices.
A key component of the Bio-Security Proficiencies Project for Beginning Producers is the use of a scaled risk assessment tool (low risk; moderate risk; high risk) for on-farm assessments. Specifically, youth implement on-farm risk assessments that, subsequently, inform risk mitigations and effect changes in their bio-security practices. This "learning by doing" approach is a foundational educational strategy of 4-H programming and is considered the "backbone" of the 4-H experience (Enfield, 2001). Other important pedagogical strategies employed in the sequence of proficiencies include: inquiry-based activities facilitated in group settings that promote reflection and dialogue, components of learning in a social environment that are critical to knowledge development (Lave & Wenger, 1991; Vygotsky, 1978); and the application of knowledge and skills to real-world problems, a strategy that helps youth foster critical thinking skills and gain a deeper understanding of content (Jones, 2012).
Although the results from the study reported here cannot be generalized beyond the scope of the investigation, the Bio-Security Proficiencies Project for Beginning Producers has the potential to provide 4-H programs nationally with a comprehensive and effective approach to educating youth and facilitating positive change in their bio-security practices. Specifically, the outcome data from the investigation revealed that the project was successful in improving youths' conceptual understanding of bio-security, biological and financial risk management, and risk mitigation; advancing their skills associated with best bio-security practices; and supporting the mitigation of disease transmission risks on their home farms and at public venues. Additionally, project impacts were extended to community members and members of the animal agriculture industry and allied professions.
Results also showed regular attrition in youth participation over time. The project required a sustained commitment over an extended period by youth and their families; accordingly, some youth, due to various reasons, were unable to complete the proficiencies. Thus, project staff recognized that future efforts must include additional strategies to help reduce the number of youth that attrite.
Animal owners are the first line of defense against disease incursion. The Bio-Security Proficiencies Project for Beginning Producers in California 4-H supported youth in the advancement of their knowledge and skills related to bio-security and financial risk management; the project also provided youth with opportunities for the authentic application of their understanding and abilities to their on-farm practices. Furthermore, participating 4-H members were able to extend their knowledge, skills, and practices to their communities.
Amass, S. F., Schneider, J. L., & Kenyon, S. J. (2004). Investigations of the ability to determine final destinations of pigs exhibited at the 2002 Indiana state fair. Journal of Swine Health and Production, 12(6), 282-284.
American Sheep Industry Association. (2014). Biosecurity for Sheep Production ASI Fact Sheet. Retrieved from: http://www.sheepusa.org/biosecurity
Anderson, D. E. (2010). Survey of biosecurity practices utilized by veterinarians working with farm animal species. The Online Journal of Rural Research and Policy, 5(7), 1-13.
Animal and Plant Health Inspection Service (APHIS). (2012). Biosecurity on U.S. Feedlots. APHIS Info Sheet. Washington, D.C.: United States Department of Agriculture. Retrieved from: http://veterinaryextension.colostate.edu/menu2/Cattle/Feed11_is_Biosecurity.pdf
Brandt, A., Sanderson, M., DeGroot, B., Thomson, D., & Hollis, L. (2008). Biocontainment, biosecurity, and security practices in beef feedyards. Journal of the American Veterinary Medical Association, 232(2), 262-269.
California Department of Food and Agriculture [CDFA]. (2014). Biosecurity. Retrieved from: http://www.cdfa.ca.gov/ahfss/animal_health/Biosecurity.html
Caraviello, D. Z., Weigel, K. A., Fricke, P. M., Wiltbank, M. C., Florent, M. J., Cook, N. B., Nordlung, K. V., Zwald, N. R., & Rawson, C. L. (2006). Survey of management practices on reproductive performance of dairy cattle on large U.S. commercial farms. Journal of Dairy Science, 89, 4723-4735.
Croasmun, J. T., & Ostrom, L. (2011). Using Likert-type scales in the social sciences. Journal of Adult Education, 40(11), 19-22.
Food and Agricultural Organization (FAO) of the United Nations (1999). FMD in Panay Island, the Philippines. EMPRES Transboundary Animal Diseases Bulletin, No. 11. Retrieved from: http://www.fao.org/docrep/x3444e/x3444e02.htm
Harrison, S., & Eborn, B. (2012). Idaho 4-H livestock costs and returns estimate. University of Idaho Extension. Retrieved from: http://extension.uidaho.edu/jerome/files/2013/10/Idaho4HLivestockCostandReturnsEstimateforSwine.pdf
Jones, R. A. (2012). What were they thinking? Instructional strategies that encourage critical thinking. The Science Teacher, 79(3), 66-70.
Keen, J. E., Wittum, T. E., Dunn, J. R., Bono , J. L., Durso, L.M. (2006). Shiga-toxigenic Escherichia coli O157 in agricultural fair livestock, United States. Emerging Infectious Diseases, 12(5), 780-786.
Kirkpatrick, F. D,, & Neel, J. B. (n.d.). 4-H market steer handbook. Department of Animal Science, Cornell University Cooperative Extension. Retrieved from: http://www.ansci.cornell.edu/extension/beef/beefu9.pdf
Lave, J., & Wenger, E. (1991). Situated learning: Legitimate peripheral participation. Cambridge, U.K.: Cambridge University Press.
Leite-Browning, M. (2008). Contagious ecthyma (orf/sore mouth) in sheep and goats. Alabama Cooperative Extension, Alabama A & M University. Retrieved from: http://www.aces.edu/pubs/docs/U/UNP-0063/UNP-0063.pdf
Leite-Browning, M. L., Browning, R., Vaughn, C. F., Andries, K., & Simon, M. (2011). Biosecurity measures for meat goat and sheep managers. FAZD Center, Texas A&M University. Retrieved from: http://www.aces.edu/urban/spanish/documents/BiosecurityMeasuresGoatSheepManagers.pdf
Moore, D. A., Kohrs, P., Baszler, T., Faux, C., Sathre, P., Wenz, J. R., Eldridge, L., & Li, H. (2010). Outbreak of malignant catarrhal fever in cattle associated with a state livestock exhibition. Journal of the American Veterinary Medicine Association. 237(1), 87-92.
Nolen, R. S. (2003, February 15). Emergency Declared: Exotic Newcastle disease found in commercial poultry farms. Journal of the American Veterinary Medicine Association, 222(4), 411.
Olson, S. R., & Gray, G. C. (2006). The Trojan chicken study, Minnesota. Emerging Infectious Disease, 12(5), 795-799.
Paarlberg, P. L., Seitzinger, A. H., Lee, J. G., & Mathews, K. (2008). Economic impacts of foreign animal disease. ERR-57. Washington, D.C.: United States Department of Agriculture Economic Research Service.
Pedersen, J. C., Senne, D. A., Woolcock, P. R., Kinde, H., King, D. J., Wise, M. G., Panigrahy, B., & Seal, B. S. (2004). Phylogenetic relationships among virulent Newcastle disease virus isolates from the 2002–2003 outbreaks in California and other recent outbreaks in North America. Journal of Clinical Microbiology, 42, 2329–2334.
Raidl, M., Johnson, S., Gardiner, K., Denham, M., Spain, K., Lantin, R., Jayo, C., Liddil, A., & Barron, K. (2004). Use retrospective surveys to obtain complete data sets and measure impact in extension programs. Journal of Extension [On-line], 42(2) Article 2RIB2. Available at: http://www.joe.org/joe/2004april/rb2.php
Roug, A., Byrne, B. A., Conrad, P. A., & Miller, W. A. (2012). County fairs as an interface for transmission of zoonotic pathogens. Comparative Immunology, Microbiology & Infectious Diseases, 36(3), 303-308.
Smith, M. H. (2009). Addressing issues of bio-security in 4-H animal science. Progress Report, Center for Food Animal Health, School of Veterinary Medicine, University of California, Davis.
Smith, M. H., & Enfield, R. P. (2002). Training 4-H teen facilitators in inquiry-based science methods: The evaluation of a "step-up" incremental training model. Journal of Extension [On-line], 40(6) Article 6FEA3. Available at: http://www.joe.org/joe/2002december/a3.php
Smith, M. H., Meehan, C. L. et al. (2009). Youth Development through Veterinary Science. Oakland, CA: Communication Services, University of California Division of Agriculture and Natural Resources. Retrieved from: http://anrcatalog.ucdavis.edu/Items.aspx?hierId=10900
Smith, M. H., Meehan, C. L. et al., (2011). Bio-Security in 4-H Animal Science. Oakland, CA: University of California, Division of Agriculture and Natural Resources. Retrieved from: http://4h.ucanr.edu/Projects/Curriculum/FREE/Bio-Security_in_4-H_Animal_Science/
Smith, M. H., Meehan, C. L. et al. (In press). Pre-Harvest food safety in 4-H Animal Science. Oakland, CA: University of California, Division of Agriculture and Natural Resources.
Smith, M. H., & Meehan, C. L. (2012). Assessment of bio-security risks associated with 4-H animal science exhibition practices in California. Journal of Extension [On-line], 50(3) Article 3FEA10. Available at: http://www.joe.org/joe/2012june/a10.php
Steinmuller N., Demma, L., Bender, J. B., Eidson, M., & Angulo, F. J. (2006). Outbreaks of enteric disease associated with animal contact: not just a foodborne problem anymore. Clinical Infectious Diseases, 43(12), 1596-1602.
Techanun, J., Meehan, C. L., Chalfant, J., & Smith, M. H. (2013a). Bio-Security and financial risk. Final Report, Western Center for Risk Management Education, Washington State University.
Techanun, J., Meehan, C. L., Chalfant, J., & Smith, M. H. (2013b). Risky business. Final Report, Western Center for Risk Management Education, Washington State University.
United States Department of Agriculture. (2012). Biosecurity in small-scale U.S. livestock operations. Veterinary Services Info Sheet. Retrieved from: http://www.aphis.usda.gov/animal_health/nahms/smallscale/downloads/Small_scale_is_Biosecurity.pdf
United States Department of Agriculture. (2011). Research, education and economics information system report: 4-H activities 2011. Washington, D.C.: United States Department of Agriculture. Retrieved from: http://www.reeis.usda.gov/portal/page?_pageid=193,899783&_dad=portal&_schema=PORTAL&smi_id=31
Vygotsky, L. (1978). Mind in society: The development of higher psychological processes. M. Cole, V. John-Steiner, S. Scribner, & E. Souberman (Eds.). Cambridge, MA: Harvard University Press.
World Health Organization (WHO), (2011). Avian influenza: "Bird flu." Media Centre Factsheet. Retrieved from: http://www.who.int/mediacentre/factsheets/avian_influenza/en/