Ricardo Hummes Rauber, DVM MSc PhD
Animal Health Consultant

Biosecurity is a set of technical procedures – conceptual, operational and structural – that aim to prevent or control the contamination of herds by infectious disease agents that may have an impact on animal productivity (focus on Animal Health) and on the health of consumers (focus on Public Health).

From a theoretical point of view, this set of procedures encompasses nine components, which are defined below:

1 – Isolation: The first step in Biosecurity is to prevent external pathogens from entering the farm. This can be achieved through physical isolation of the property, which includes the use of fences, walls, and/or other physical barriers to prevent the entry of unauthorized people, vehicles, and wildlife, and virtual isolation, which includes the procedures adopted for effective access to farms and sheds.

2 – Traffic control: Poultry farms should limit access to authorized people and vehicles only. A traffic control plan should be in place to limit the number of people and vehicles entering the farm and ensure that they follow appropriate biosecurity protocols before and during access.

3 – Cleaning and disinfecting: Proper cleaning and disinfecting are essential to prevent the spread of disease. Cleaning should be done to remove organic material and disinfection should be done to eliminate any remaining pathogens. All equipment and materials should be cleaned and disinfected after use and all surfaces in the shed should be thoroughly cleaned and disinfected.

4 – Quarantine, medication and vaccination: All animals that are introduced into the flock must remain in quarantine for a period to monitor for signs of illness. When appropriate, sick flocks or animals should be medicated as soon as possible. Vaccination should be considered a preventive measure against known diseases in the region.

5 – Monitoring: Regular monitoring of the herd is necessary to detect the presence and evolution of diseases. This can include monitoring animals for clinical signs, conducting laboratory tests and necropsies, and using sentinel animals to detect the presence of disease.

6 – Eradication: If a disease is detected, affected animals should be removed from the flock and treated or euthanized. The area should be cleaned and disinfected thoroughly and the remaining animals should be monitored for signs of illness. In general, where applicable, eradication considers the elimination of all the animals that make up the affected flock.

7 – Audit: Regular audits should be carried out to ensure that the biosecurity is monitored and to identify points for improvement.

8 – Continuing Education: Proper education and training of all personnel is essential for a successful biosecurity. This includes training on biosecurity protocols, disease detection, and emergency response.

9 – Contingency plan: There should be a contingency plan in place to outline the measures to be taken in the event of a disease outbreak. This plan should include protocols for isolating affected lots, cleaning and disinfecting the area, and communicating with regulatory authorities and other stakeholders.

The points described above are theoretical and may have limited applicability in the current pig production system, as is the case of eradication, which only effectively applies to diseases that are currently exotic in Brazil. However, from a practical point of view, most of them are applicable in the current reality of pig farming to the same extent that they are important for the maintenance of animal health.

In general, a superficial approach to the concept of isolation refers to the geographical isolation of the farm, with considerable distances from any other type of production unit or animal husbandry, including a green belt of a few hundred meters on the perimeter of the farm. However, this reality, if it was ever common, is currently increasingly rare and a more in-depth approach to this concept brings to light a series of procedures that must be adopted to fully comply with what is expected in terms of isolation of the farm, shed or animals.

Limiting access to pig production facilities to authorized personnel only is an essential biosecurity measure. Allowing unauthorized people or vehicles into the facility increases the risk of introducing pathogens that can infect animals. People and vehicles can bring in pathogens from other locations, and equipment can also serve as carriers for disease-causing agents. Therefore, strict protocols must be established for the movement of people, animals and equipment inside and outside the farm, which include the installation of anti-bird screens in the sheds, perimeter fences in the farms or nuclei and facilities for the execution of sanitary barrier procedures, from a structural point of view, in addition to the implementation of procedures such as bathing,  change of clothes and shoes, disinfection of materials and vehicles, registration of access of people and vehicles, control of rodents and other pests, among others.

Disinfecting vehicles and equipment is an important step in preventing the spread of pathogens. Vehicles entering the farm must be cleaned and disinfected thoroughly before entering and leaving. Visitors and staff must wear clothing unique to each farm. These measures help minimize the risk of disease transmission from external sources.

Keeping facilities and equipment clean is crucial to prevent the spread of disease. A clean environment helps reduce the risk of exposure to disease-causing pathogens. Cleaning and disinfection of facilities and equipment must be carried out regularly and in accordance with strict protocols. For effective compliance with cleaning and disinfection protocols, the practice of all-in-all-out housing is essential and it refers to a strict hygienic-sanitary management practice in which all animals in a given compartment, sector or facility enter at the same time and are removed together, without mixing with other animals in different stages of growth, different ages or health conditions. This is essential to ensure that the area can be thoroughly cleaned and disinfected before introducing new animals.

The all-in-all-out practice allows each compartment to function as an independent biosecurity unit. This means that even within a single farm or facility, different enclosures can operate in isolation from each other in terms of sanitary control, facilitating disease management and preventing the spread of infectious agents between enclosures. This strategy is particularly useful in breeding farms, in which, in practice and even considering each shed independently, effective emptying is not possible. Thus, in a compartmentalized or sectorized way, it is possible to meet a minimum of conditions for effective compliance with cleaning and disinfection procedures. The segregation of the farm or facility into compartments in which the all-in-all-out concept is applied, therefore, offers an effective strategy for sanitary management, promoting a more controlled and safer environment for the growth and development of animals, in addition to contributing significantly to the prevention of diseases and to efficient and sustainable production.

It is important to emphasize that, for nursery and growth/finishing farms, it is possible to establish a logistics for receiving and shipping animals in order to provide the effective application of the all-in-all-out concept, favoring another important aspect of biosecurity and sanitary programs for pig farms, which is the uniformity of ages of the animals in these farms. In other words, segmentation within the epidemiological unit itself is not recommended for these farms, under penalty of compromising sanitary and zootechnical results.

Regular monitoring of animal health is essential for early detection of diseases. Batches of animals that show signs of disease should be isolated, diagnosed, and have appropriate treatment protocols in place to prevent the spread of the disease. Monitoring can be done through clinical observation of the pigs for signs of disease, such as lethargy, loss of appetite, or respiratory distress, through necropsy evaluations, or by collecting and analyzing samples, such as blood, feces, saliva, or other materials. Variations in water consumption can also be indicative of health changes in the flock.

Vaccination is an effective tool to prevent the spread of certain diseases in pig populations. Vaccination programs must be designed and implemented by the veterinarian responsible for the sanitary control of the herd, which will consider the animal category (breeding or cutting), the conditions of the farms, the challenges of the region, seasonal variations, among other factors. In this context, some crucial points related to vaccination stand out:

1 – Definition of diseases for which vaccines will be used:

1.1.      Prevalence of the Infectious Agent: The prevalence of certain pathogens in the region or in the specific production unit should guide the selection of vaccines. It is imperative to understand which diseases are most common and which pose significant risks to animals.

1.2.      Epidemiological Importance: Diseases with high transmissibility and that can cause severe outbreaks deserve special attention. Vaccination, in these cases, acts as a protective barrier, minimizing the spread of infectious agents.

1.3.      Impact on the Production Phase: The production stage of the animals influences the vaccination program. Sows, for example, need a vaccination protocol that considers their reproductive function, while beef pigs require protection against diseases that affect their growth and development.

2 – Definition of the Vaccination Program:

2.1.      Types of Vaccines: There are different types of vaccines available, including live attenuated, inactivated, and subunit vaccines. The choice depends on the target disease, the age of the pigs and the specific goals of prevention.

2.2.      Age for Vaccination: The ideal age for vaccination varies according to the disease in question and the immunological dynamics of the animals.

2.3.      Number of Doses: Some vaccines require multiple doses to ensure adequate immunity.

2.4.      Route of Application: Vaccines can be administered in different ways, such as subcutaneous, intradermal or intramuscular injections, orally or by sprays.

2.5.      Maternal Antibodies: Considering the presence of maternal antibodies is crucial, as they can interfere with the effectiveness of vaccination in piglets.

3 – Vaccine and Vaccination Care:

3.1.      Transport and Storage Conditions: Vaccines must be transported and stored at appropriate temperatures to preserve their effectiveness.

3.2.      Equipment Maintenance: Vaccination equipment should be cleaned, disinfected, and well-maintained.

3.3.      Needle Size: The needle should be of an appropriate size for the type and age of the pigs, and should be changed frequently to avoid contamination and tissue damage.

Vaccination is a process that requires detailed planning and careful execution. Identifying the relevant diseases, defining an appropriate vaccination program and taking precautions during the handling and application of vaccines are indispensable steps to ensure the success of pig immunization and, consequently, promote the health and productivity of the herd.

In addition to a well-designed and executed vaccination program, it is necessary to pay attention to the preventive programs adopted with a focus on intestinal health, which must be designed according to the needs of each herd, especially in antibiotic-free growth promoter (AGP-Free) production systems and may include broader strategies than simply the control of pathogens such as the modulation of the intestinal microbiota and support for the immune system in general. Special attention should be paid to sows’ gut health programs as this is not only crucial for the nutrition and well-being of the sow herself but also directly influences colostrum quality and the subsequent development of piglets. A well-designed preventative program for gut health is critical, possibly involving the use of probiotics, prebiotics, phytogenics, and organic acids among other strategies via food, along with appropriate management practices. These measures are vital to promote a healthy gut microbiota in sows, resulting in colostrum rich in antibodies and essential nutrients, providing piglets with a robust and protected start in life.

Preventive gut health strategies are essential, especially in antibiotic-free growth promoter (AGP-Free) production systems, where sustainable gut health is central to productive success. Investing in a careful program not only elevates the health status of sows and piglets, but also boosts the productivity and sustainability of the swine herd as a whole.

The quality of the water supplied to animals plays a fundamental role in their health. It should be noted that water is an important nutrient for animals and its microbiological and physicochemical quality should be observed. In general terms, microbiological quality is guaranteed through compulsory chlorination, with levels of around 3 ppm of free chlorine at the point of water consumption furthest from the chlorination point. With regard to the physicochemical quality, both the hardness and pH of the water should be observed and, whenever possible, corrected. Remember that waters with a slightly acidic pH (between 5.0 and 6.5) are ideal, from the point of view of animal health, as they favor the presentation of chlorine in the form of hypochlorous acid, which is the active form against microorganisms. In addition to the quality of the water itself, it is necessary to ensure proper cleaning and disinfection of the entire water supply system to the animals, including the reservoir and pipes.

Proper training of personnel is essential for maintaining a robust biosecurity program. Employees should be educated on the importance of biosecurity measures, as well as how to implement and follow them. Regular training can help reinforce the importance of these measures and ensure that all personnel are aware of the latest biosecurity protocols. Proper training also reduces the likelihood of human error, which can lead to the introduction of disease-causing agents into the herd.

The success of a biosecurity program necessarily depends on the people involved in the production process. In this sense, it is essential not only to train the teams adequately and constantly but also to listen to what they have to say about the program already implemented and the possible improvements to meet the theoretical premises of a program and make it feasible from an operational point of view.

Biosecurity is a critical aspect for maintaining the health and productivity of pig herds. With the reduction in the use of antibiotics, preventing the introduction and spread of diseases becomes even more important. It should be noted that a biosecurity program must be designed and implemented according to the characteristics of the production system to which it is proposed, considering the specific particularities of the farms, animal categories, geographic situation, and challenges, among other criteria. In addition, the biosecurity program is not static, undergoing constant improvement over time and following the evolution of other aspects related to animal production, such as management and nutrition standards.

 

SUGGESTED BIBLIOGRAPHY

MORÉS, N.; CARON, L.; COLDEBELLA, A.; BORDIN, L. C. Biosseguridade mínima para

granjas de suínos que produzem animais para abate. Concórdia: EMBRAPA SUÍNOS E AVES. 38p. 2017.

RIBAS, J. C. R.; DIAS, C. P.; LUDTKE, C. B.; BUSS, L. P. eds. Suinocultura: uma saúde e um bem-estar. Brasília: MAPA – Ministério da Agricultura Pecuária e Abastecimento. 500p. 2020.