December 2006 // Volume 44 // Number 6 // Feature Articles // 6FEA1

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How Farm Workers Learn to Use and Practice Biosecurity

Biosecurity is any practices, policies, or procedures employed on a farm to prevent and/or control disease entering a farm, or moving around a farm. Using Grounded Theory methodology, the study reported here investigated biosecurity use among workers at finfish recirculation aquaculture facilities in the U.S. and Canada. Farm workers learned to use and continually practice biosecurity through a three-phase, step-wise process of orientation, routine, and thoughtful approach. Certain elements in the work environment and different characteristics of the individual worker influenced the worker's practice of biosecurity on a farm. The findings are relevant to biosecurity practice in all livestock-farming industries.

Julie Delabbio
Northwestern State University
Aquaculture Research Center
Natchitoches, Louisiana


Biosecurity can be defined as any practices, policies, or procedures employed on a farm to prevent and/or control disease entering onto the farm or moving around the farm. Biosecurity includes simple practices related to animal husbandry such as daily cleaning of holding units, disposal of dead animals, and feeding regime. Biosecurity can also involve farm policies and procedures concerning admission of visitors, animal introductions onto the site, and equipment disinfection.

Consistent use of high-quality biosecurity is essential to the success of any type of livestock agriculture. Yet, in many sectors of agriculture, the practice of biosecurity is sporadic and of a variable nature (Gifford, 1987; Thomson, 1997; Amass & Clarke, 1999; Godkin, 1999; Sanderson, Dargatz, Garry, 2000). Traditional thinking has been that lack of knowledge about biosecurity is the major reason for poor biosecurity practice (Gillespie, 2000; Sanderson et al., 2000; O'Bryen & Lee, 2003). Extension agents, therefore, have continued to try to promote better biosecurity practice at the farm level by providing educational materials, demonstrations, workshops, etc., to farmers and their workers. However, Extension agents and farm management could be more effective in changing poor biosecurity practice by farm workers if they better understood the process and elements that influence the workers' actions.

Recent work by Delabbio et al. (2003, 2004, 2005) has shown that the frequency and type of biosecurity practiced on a farm was not driven solely by levels of awareness or knowledge about biosecurity. Different characteristics of the farm, such as species grown, staff size, and/or source of water influenced the type of biosecurity practiced on a farm. As well, the beliefs, attitudes, and perceptions of the farm manager and/or owners about biosecurity and disease affected the biosecurity practiced on a farm.

The purpose of the study reported here was to examine how farm workers learn and practice biosecurity. The participants in the study were workers (farmhands) employed at fish farms in the United States and Canada. Although the aquaculture sector of agri-business was used as the arena for this research, the findings of this study are applicable to other livestock-rearing industries. On any farm, it is the farm workers who are responsible for the daily upkeep of the animals, equipment deployment, food storage, etc., and therefore are responsible for the daily biosecurity practices embedded in these activities.


In spring 2002, tape-recorded interviews of approximately 1-hour duration were conducted with 31 individuals employed at 12 salmonid recirculation facilities in West Virginia and Maine, USA, and in New Brunswick, Canada. Interviewees were full-time farm personnel who worked directly with the animals (fish) and, therefore, had hands-on, daily opportunities to practice biosecurity. Hereafter, the interviewees are referred to as "workers." The focus of the interviews was the workers' perceptions of, and experiences with, farm biosecurity. Specifically, the interviews examined the following two questions:

  1. How do farm workers learn about, use, and perceive biosecurity practices in the workplace?

  2. What influences workers' practices of biosecurity?

A qualitative research methodology called "Grounded Theory" was used for data collection, organization, and analysis (Glasser & Strauss, 1967; Glasser, 1992). This research methodology was chosen because it has proven to be a useful and robust means of examining undescribed human phenomena.

Grounded Theory uses a systematic approach to establishing categories and themes, and to generate theory from a qualitative data set. In the study, the emergent theory describes how farm workers learn to use and practice biosecurity on the farm. This theory also describes the influence of elements in the work environment and characteristics of the individual worker on the practice of biosecurity. This theory is called the "Practice of Biosecurity Theory" (PBT).


Practice of Biosecurity Theory

A farm worker's practice of biosecurity is an interactive, constantly dynamic process, which can be influenced by several distinct factors in the work environment (Figure 1). A farm worker learns about and practices biosecurity through a three-phase process. This process is never finite; a worker may go through the process many times during their time of employment on a farm as rearing conditions change and/or new disease concerns arise.

Figure 1.
How Phases of the Learning Process and Factors in the Workplace Interact and Influence the Practice of Biosecurity by Farm Workers

How Phases of the Learning Process and Factors in the Workplace Interact and Influence the Practice of Biosecurity by Farm Workers


The following is a more detailed description of the three phases of the process. To give voice to the data, examples of the workers' comments are included with the description. However, it is important for the reader to note that the findings of this study were derived from an extensive data, not solely from the embedded comments found in the text.

Practicing Biosecurity: A Three-Phase Process

Phase One: Orientation

The first phase that a worker experiences in his/her efforts to use biosecurity on a farm is the orientation phase. This phase begins on the initial day of employment and incorporates the period of time during which the new worker "learns the ropes" about caring for the fish and other responsibilities related to site biosecurity. During this phase, workers usually are assigned to work with experienced personnel who act as role models/mentors and who use verbal instruction and hands-on demonstration to teach the workers about biosecurity as it relates to their job responsibilities. The length of this phase varies depending upon staffing resources and the size and complexity of the facility.

The orientation phase includes learning/using biosecurity in three categories of tasks: (1) standard husbandry activities for providing physical care for the fish, e.g., tank cleaning, fish feeding; (2) housekeeping duties, e.g., feed storage; and (3) seasonal activities, e.g., vaccination, harvesting. During this phase, workers become aware of the required time sequence of biosecurity tasks as well how to perform actual tasks.

Phase Two: Routine

Routine, the second phase, describes the period of time when workers start to work alone, or independent of constant supervision. During this phase, workers get greater experience and practice in applying their newly acquired knowledge about biosecurity to day-to-day farm activities. Workers will still continue to observe the biosecurity practices of more experienced staff, and over time, the workers may improve their own efficiency and delivery of these practices.

Workers will also modify their practice of biosecurity as they themselves learn through trial and error the impact of their actions on the fish. For instance, during the daily feeding, workers may change their own actions in feeding the fish in response to the fishes' behavior and the impact feeding has on a tank's water quality.

Workers explained that during the orientation phase, their role model would identify specific biosecurity measures and provide some explanation as to why they were used. In this phase, the worker was highly conscious of his actions. However, a common comment among workers performing these same biosecurity measures during phase two of the process was that over time, as the practice of a certain biosecurity measure became more of a habit or routine, workers no longer consciously thought of the significance of the action. One worker explained, "It [the biosecurity measure] becomes second nature," while another worker said, "You do it without even thinking about it."

Phase Three: Thoughtful Approach

The third phase of the process of learning to practice biosecurity is called "thoughtful approach." This phase commenced when workers began to develop and use biosecurity measures designed for new experiences. During this third phase, workers continued to use biosecurity measures based on the knowledge acquired during orientation and the trial-and-error exercise found in establishing a routine. However, as circumstances changed with entrance of new fish groups, new disease concerns, and the introduction of new culture methodologies, workers described how they adapted their expectations and practices of biosecurity based on the site's specific biosecurity needs and found this approach to be more effective.

In contrast to the practice of biosecurity in the previous phase (routine), the workers' practice of biosecurity was now guided by familiarity with the fishes' health needs, new information from external sources, and a more holistic understanding of biosecurity utilization. For example, one worker, reflecting on how he approached different fish life stages with different biosecurity expectations, said:

If you screw up with your fry, the fry don't start dying off in the next month or two, they can all be dead by tomorrow. So there is this different sense of urgency with these things. They are so delicate, so perishable compared to the other fish.

Not all workers in the study had processed to this third phase of learning in the use of biosecurity. Workers in this phase described an outward seeking perspective for new information on fish disease and control, and maintained a network of external information sources, a dissimilar situation to those workers who performed biosecurity as a routine and duty practice only. One worker explained:

I have been at it (aquaculture) long enough, but still things pop up that you don't expect, haven't seen before. But at least you have a sort of repertoire of people that you have association with or know or have some sort of relationship with, and you know what their specialties are and what their interests are. So although you many not have the answers, matter of fact, if you had all the answers, you'd be pretty unique. But you know where to go to get an answer.

In this phase of the process, workers emphasized overall fish care and system management as more important to biosecurity than individual biosecurity measures. For example, one worker said:

I'd rather put more importance on the system that is really, really good for growing fish and grows really healthy fish. That would probably take precedence over separating of (year) classes or anything like that. I honestly think that the host has to be weak in order to get sick… it's the whole picture, the environment and the host… its not just disease getting on your site, but the fact that if disease comes on your site, does it really have the ability to infect.

In addition, workers in the thoughtful approach phase felt that biosecurity practices needed to be discretionary, appropriate to the perceived risk, and therefore site and situation specific. Workers considered different biosecurity practices differently with respect to their level of risk reduction. For example, several workers talked about the difference in level of risk associated with different types of visitors to the fish-rearing component of the facility (office staff versus feed truck personnel versus personnel from another farm versus the general public). These workers adapted their application of biosecurity to the different levels of fish disease risk associated with the different visitors.

The Workplace Environment

Intrinsic and extrinsic conditions in the workplace environment were identified as influencing workers' practice of biosecurity. Many of these conditions were interconnected. These conditions were grouped into three categories: management's action, peer pressure, and personal characteristics of the individual worker.

Management's Actions

Workers identified management's position on biosecurity as influential to their own learning and practice of biosecurity. Workers perceived the use of biosecurity practices on a farm as a function of doing business. One worker explained, "Biosecurity is a business decision as far as I'm concerned. I mean, it has absolutely nothing to do with government [regulations] or food safety. It has everything to do with healthier stock." Another worker observed, "It [the use of biosecurity] is market-driven . . . as business gets more competitive. This group doesn't have disease and this group does. Which group of fish are you going to buy? You know as the supply increases . . . there is going to be more concern about disease." To some degree, the workers' perceived management's action towards biosecurity on the farm as indicative of management's commitment to running a successful business.

Management transmitted this message of commitment to the farm workers in a variety of ways: by giving positive and negative feedback on the worker's practice of biosecurity, supplying information on fish performance in relationship to biosecurity practices, and ensuring adequate resources for the practice of biosecurity. One worker, explaining how positive feedback influenced his practice of biosecurity, said:

If you don't invest anything in your employees and you don't build them up, build their confidence up, let them know when they're doing a good job and things like that, then they're not going to try, and that's where you get those breakdowns in biosecurity. It is that someone, wandering around, who hasn't been told they're doing a good job and [they] don't really care.

Another worker commented on the influence of positive feedback as follows:

It [encouragement] makes people conscientious when it comes to things like biosecurity, because they feel it's very important to them, and they feel like they're very worthy, and they're very important in the whole scheme of things. You know, you make them feel important and they feel that things like biosecurity are important.

However, workers also mentioned that negative feedback on the practice of biosecurity from management also influenced the level of biosecurity that they practiced. This negative feedback was described as threats, firings, meanness, fines, and creating paranoia about consequences of disease incidence. In both types of feedback situations, it was evident that workers were aware of management staff's scrutiny of their biosecurity activities.

Workers' biosecurity practice was also influenced by the amount of information that they received from management personnel on how the fish were performing, what impact certain rearing conditions had on fish performance, and what the workers' contributions were to the facility's overall success. As one worker reflected:

Well, when I first started working here, there were biosecurity measures in place, but I don't think there was a good understanding of where it was important to have it and a very good understanding as to why--why you would have it and where it is applicable.

The availability of required resources to actually perform biosecurity was also seen by workers as a strong supportive influence in their practice of biosecurity. Resources that supported the practice of biosecurity included: proper facility design; pieces of equipment and supplies to augment or perform biosecurity practices (e.g., disinfectants, hand wash stations); and sufficient time and labor allocated to perform biosecurity practices. Some workers expressed frustration that they would like to perform better biosecurity, but were unable to because of lack of resources.

Peer Pressure

Peer pressure was identified by workers as significantly influencing their practice of biosecurity. This was a separate influencing element from the pressure by management to practice biosecurity. As one worker described it:

If you see somebody else, say, two or three of you are going into a building to do a job, and the first person steps in the footbath, well, you're going to do it. You know, follow-the-leader type thing. You would be more apt not to [use the footbath] if the person in front of you didn't… it's easier to do it if everyone else is doing it.

Workers acknowledged that their sense of accountability to their peer group affected their practice of biosecurity. Some farms had methods of visible accountability to the group with respect to biosecurity use, such as posting specific biosecurity duties of different workers in common rooms/ work areas. On other farms, although responsibility of assignments was less formal, it was commonly known among the staff who was responsible and, therefore, accountable for the performance of certain biosecurity practices (e.g., changing disinfectant in foot baths).

Some workers acknowledged that to them failure to practice biosecurity was seen as failure to the group because biosecurity was linked to job security. For example, one participant said, "I feel like it is my job to do that [remind other people if they fail to use biosecurity measures] . . . because it is putting other people's jobs on the line." Because of this job-security link, workers felt that having other people monitor and check their use of biosecurity was important.

At some farms, workers spoke of formal review of their biosecurity practice by peers and comparison with other groups within the company. At one farm, workers evaluated their fellow employees' performances as part of each worker's annual job evaluation: "We have job evaluations that we do on each other, and a big part of it is biosecurity. So, if you're not practicing proper procedures, it will be on your job review from your fellow employees." Workers at another company, which owns several farms, reported having a fish health specialist who:

Goes around facility to facility and basically gives us a grade and tells us how good we're doing here, or how poor we're doing [in practicing biosecurity] . . . We want to be in line with everybody else in the rest of the company. It [biosecurity] has improved.

The link of biosecurity practice and responsibility to the group was evident in other ways. Workers spoke of breaches of biosecurity by people outside of the group (outsiders and seasonal staff) and how it concerned them. "When we have different seasons, we're busier so we hire some part-timers and it's hard to get them sometimes to do some of the things [biosecurity practices]. They're only here for a few weeks." Workers perceived that a responsibility to fellow employees to practice biosecurity had not developed among casual employees because of the limited amount of time that these persons were exposed to the group.

Characteristics of the Individual Worker

Workers felt there were four characteristics of individuals that influenced their practice of biosecurity in the workplace. These characteristics were 1) the individual's personality type, 2) the individual's experience with fish disease, 3) the individual's education level, and 4) the individual's personal beliefs about fish health, disease incidence, disease prevention, and control.

Personality Type

Workers saw an individual's practice of biosecurity as a natural extension of the person's personality type. For example, workers believed that persons who were responsible, tidy, and job-conscientious were more likely to perform required biosecurity measures.

Experience with Fish Disease

All workers interviewed either had direct experience with fish disease problems during their employment in aquaculture or had personal contact with people (family members, neighbors, or other farm personnel) who had had problems with fish disease in their stock. This experience with fish disease was viewed as an influence on the worker's practice of biosecurity measures. One worker reflected that he was practicing biosecurity now because, "I learned the hard way through disease transfer on the farm."

There was an oral tradition of workers describing to other workers their own experience with disease incidence present in the farm work environment. Workers felt that it was important for co-workers to be told about fish disease situations in which they themselves had been involved. So, during informal discussions (at lunch hour, during coffee breaks, etc.), experienced workers verbally informed new workers on staff of their own personal, past experiences with fish disease. These testimonials were viewed by the workers as an important influence on their own practice of biosecurity and that of other workers. One worker explained:

I've worked in industry for a long, long time. So I've had the experience with it [disease] and know what's involved and know what can happen. These guys don't. So it is important for us in our particular situation to fill them in on stuff like that [disease consequences]. They wouldn't know otherwise.


Workers talked about drawing on the knowledge gained from their formal education to practice biosecurity in their current job. However, besides formal education, workers also talked about reading scientific and popular aquaculture publications, talking to experts, and taking short courses in fish disease to increase their knowledge about fish health and therefore favorably influence their practice of biosecurity measures.

Personal Belief System

Common to all the workers was the belief that disease prevention and control were important. However, workers felt that this was important for a number of reasons. Some workers believed preventing disease was directly tied to job security. As one worker explained, "if we don't do it [biosecurity], we lose all our fish, then you lose your job." Other workers felt that practices to prevent disease occurrence [biosecurity] were important because they were part of company policy. Other workers believed the practice of biosecurity was a way to reduce disease occurrence, but did not directly link disease incidence at their site to job security.

A common belief among workers was that more fish diseases, and therefore higher disease risks, were now present in the aquaculture industry than in the past, and they said this has influenced their practice of biosecurity. Similarly, many workers believed that the increased movement of fish that was occurring in aquaculture made the risk of fish disease transmission greater and therefore influenced their biosecurity practice. As one worker stated, "Originally, way back when, we were self-sustaining. We had everything here. We weren't too concerned about bringing something into the facility. Now I am concerned because we are bringing things in like eggs and other fish."

Discussion and Implications

The most important finding of this research is that biosecurity practice on a farm is a complex, interactive process influenced by several factors in the workplace. Getting workers to use biosecurity is not a matter of simply providing information to them about disease prevention and disease control measures.

The process of learning about biosecurity and the factors affecting its use by farm workers is a study in human behavior. In order to effectively bring about change in current biosecurity practices, Extension agents and farm managers must understand what motivates and influences workers to use biosecurity.

In this regard, both farm managers and extension workers should recognize, at the farm level, the influence of:

  • Peer pressure,

  • Management's actions, and

  • The mentor role on the practice of biosecurity on a farm.

Although it is the workers who provide the fish care maintenance and practice biosecurity, management's commitment to biosecurity had a significant effect on the workers' practice of biosecurity. Workers' practice of biosecurity was directly affected by the type and availability of resources available to them and by positive and negative feedback by management on the worker's biosecurity-related actions.

Peer pressure can have an important positive influence on biosecurity practice on a farm. Farm work environments that stress a team or group approach to biosecurity activities may have better success in the consistent use of biosecurity measures. Alternatively, it may be inferred that farm sites with high personnel turnover will have weaker group dynamics, and this, in turn, might affect the practice of biosecurity.

The importance of the mentor role cannot be underestimated in the practice of biosecurity. It is during the orientation phase that workers first become aware of, and learn how to perform, biosecurity practices. The success of this unstructured educational process is dependent on the mentor's teaching abilities and amount of time given to him/her to instruct new employees. The future practice of biosecurity by workers on a farm may be strongly related to the assignment of the appropriate person to this mentoring role, and to the appropriation of sufficient time to perform the mentoring.

The study reported here was the first exploration of the human dimension of biosecurity practice on a farm at the worker level. It is recognized that the findings of the study are based on interviews of workers raising fish on farms. However, the study of the practice of biosecurity is a study in human behavior, and the problem of infrequency of use and inconsistency of application of biosecurity measures exists in most animal-rearing industries. Therefore, in a broad sense, the findings of this study are important to all livestock-rearing industries and would be of use to both farm managers, and Extension personnel hoping to improve the practice of biosecurity on any livestock farm.


Amass, S. F., & Clark, L. K. (1999). Biosecurity consideration for pork production units. Swine Health and Production, 7(5), 217-228.

Delabbio, J., Murphy, B., Johnson, G. R., & Hallerman, E. (2003). Characteristics of the recirculation sector of finfish aquaculture in the United States and Canada. International Journal of Recirculating Aquaculture, 4, 5-23.

Delabbio, J., Murphy, B., Johnson, G. R., & McMullin, S. L. (2004). An assessment of biosecurity utilization in the recirculation sector of finfish aquaculture in the United States and Canada. Aquaculture, 252, 165-179.

Delabbio, J., Johnson, G. R., Murphy, B., Hallerman, E., Woart, A., & McMullin, S. L. (2005). Fish disease and biosecurity: Attitudes, beliefs and perceptions of managers/owners of finfish recirculation facilities in the United States and Canada. Journal of Aquatic Animal Health, 17(2),153-159.

Gifford, D.H., Shane, S. M., Hugh-Jones, M., & Weigler, B. J. (1987). Evaluation of biosecurity in broiler breeders. Avian Diseases, 31(2), 339-344.

Gillespie, J. R. (2000). The underlying interrelated issues of biosecurity. Journal American Veterinary Medicine Association, 5, 662-664.

Glaser, B G., & Strauss, A. L. (1967). The discovery of grounded theory: Strategies for qualitative research. Chicago: Aldine/Atherton.

Glaser, B. G. (1992). Basics of grounded theory analysis: Emergence vs. forcing. Mill Valley, California: Sociology Press.

Godkin, A., Kelton, D., Alves, D., Lissemore, K., Leslie, K., Smart, N., Church, C., & Meadows, P. (1999). Biosecurity practices to limit spread of Staphylococcus aureus on Ontario Sentinel Dairy Farms. In Proceedings of the Annual Conference of the American Association of Bovine Practitioners (pp. 254-255).

O'Bryen, P. J., & Lee, C. S. (2003). Discussion summary on biosecurity in aquaculture production systems: exclusion of pathogens and other desirables. In C.S. Lee & J. P. O'Bryen (Eds.) Biosecurity in aquaculture production systems: Exclusion of pathogens and other desirables (pp. 275-293). Baton Rouge, Louisiana: The World Aquaculture Society.

Sanderson, M. W., Dargatz, D.A., & Garry, F.B. (2000). Biosecurity practices of beef-cow calf producers. Journal of American Veterinary Medical Association, 217(2), 185-189.

Thomson, J. U. (1997). Implementing biosecurity in beef and dairy herds. In Proceedings of the Annual Conference of the American Bovine Practitioners (pp. 8-14).