Biosecurity is one of the most important parts of the process of swine production. It is a set of practices designed to prevent the entry and transmission of pathogens in farms, a strategic and integrated idea which includes regulatory frameworks and allows managing those risks which can be found in food safety and animal health.

Biosecurity has to be approached with integrated knowledge, habits and behaviours that must be incorporated by all personnel involved in the farm. If the team complies with the rules, negative impact on animal production will be minimized.

Biosecurity is our best investment for swine production also it will generate more income in our farms, because:

• Less mortality
• Animals grow faster
• Fewer growth delayed animals
• Better use of feed
• Less antibiotics are used
• More production of animals
• Animals have more weight in less time
• The genetic potential is expressed
• More revenue is generated
• Better return of investment
• Risks of transmission of diseases to human are reduced
• We work to ensure food safety

Next, we will describe which instruments we will use and which actions we will incorporate to reduce the risk of contamination of animals in farms.

1. Where to locate the farm
2. Construction peculiarities
3. Pest control (rodents, birds, dogs, insects)
4. Animals reception (GGP, GP or IA)
5. Facility disinfection
6. Animals batches with the same age
7. Vaccination and medication programs according to each farm and region
8. Control of visits and people from outside the farm (wet and dry baths)
9. Control of mortality waste
10. Waste management (stool, urine and water)
11. Vehicle handling (washing)
12. Laboratory of diagnosis

1. Where to locate the farm

Before the construction of a farm, it is essential to find the best location for it. It should be located as far as possible to other farms. Natural barriers, wind directions, water sources, among others, should be considered. This will reduce the possibility of contamination by other neighbour farms. Now, in the State of Sonora, the law establishes some conditions to build a new farm.

If our farm is already built, we must analyse the options we have in order to reduce the risks. Planting trees or placing air filtering at the entrance and exit of each shed can be some of the first actions to set up.

The minimum characteristics that we must consider for the location of a farm are the following:

• Distance from other farms (at least 5 km, the farther the better)
• Way of entry and exit
• Transit paths (slaughterhouses) and feed plants.
• Natural barriers as protection (mountains, trees…)
• Wind direction
• Swine demography
• Aquifers and rivers

2. Farm construction peculiarities for good swine production

The type of construction will make easier or more difficult to handle stool, washing and disinfection of facilities. It can be a better pathogen reservoir (in the case of wood). Nowadays we have the possibility of using plastic panels that facilitates cleaning and improve animal comfort.

Placing aviary meshes reduces the possibility of infections and save feed. That is because we are preventing birds from entering the farm and eating the feed (a broiler of 109 grams consumes 23-25 grams of feed).

The use of a good roof provides good comfort to animals, reducing stress and, indirectly, improves their immune response.

In the case of the equipment, the decision should not always be in relation to the price, this must be analyzed in relation to the needs of the animals: type of drinking fountain (height, animals for each drinking fountain), type of feeder (capacity of the feeder in kilos and in mouths), type of floor (concrete, grating, slats, ect.), type of cage or bars that separate batches of animals (rod, galvanized tube, etc.).

Everything we do regarding the construction and equipment of the farms should be aimed at providing comfort to the animals and allowing the best and easiest process of washing and disinfection of the facilities.

3. Pest control (rodents, birds, dogs, insects)

As its names indicates, pests are synonymous of infection, any of them must be combated or minimized. First, the objective will be to minimize the risk of disease transmission among farm animals. Secondly, we must avoid the pest contamination from other farms. There are a lot of publications which support the damage of pests. We should remember Otake project (2003) that demonstrates that flies can be vectors in the transmission of PRRS virus.

Lately, more emphasis has been given to birds migration, mainly for the influenza problems that have impacted on laying hens in United States or Mexico. But what other important economic factors or health diseases can be transmitted by birds?

In the case of rats, they have a great potential of Salmonella and Erysipelas transmission. There are others diseases not taken into account that may cause breaks in the biosecurity of the farm, without considering the economic losses caused by consumption and contamination of feed and destruction of facilities.

Avian migration is one of the highest risks in disease transmission.

This graph shows how there are several species that can be vectors in the transmission of Influenza virus being a risk for pig farms.

4. Animal reception

Since PRRS virus appeared, the procedures for the introduction of new genetic material to the farms have changed. They began using quarantines, changed their name to infectious or quarantine-adaptation; the natural pairing stopped, and the males ceased to have a presence on farms, now there are Artificial Insemination Centers or Centers for Genetic Improvement.

It is a fact that we must develop protocols for the entry of genetic material (females and males) either through live animals or through semen. In the case of genetically improved animals, we should develop a first-time sows adaptation program. The objective will be to unify (through direct contact with biological material of the farm or through vaccines) its immunological conditions with the other animals in the farm. When genetically improved animals are bought, it is mandatory to ask the supplier for negatives to the main diseases of pigs:  PRSS, Mycoplasma, PED, among others.

In the case of the Artificial Insemination centers, it is best that the stallions whose semen has been extracted must be PCR negative to PRRS virus and must follow animal health monitoring programs, in order to offer health security.

5. Facility disinfection

Perhaps this is one of the points where the producers set more biosecurity measures. However, this is only one part of biosecurity. To achieve a good result, it is very important to define well established protocols. The procedures should be described perfectly, by indicating which products and dose should be used and finally how to evaluate their functioning.

Protocol must include:

• Indications on how to remove organic matter.
• How to use high-tech soaps (not powders bought at supermarket) and their method of application (wet, foam, etc.)
• Drying period.
• Define what disinfectant to use, knowing how each of the chemical agents act on the pathogens of importance in pig production. Define the way of use: wet, nebulized, foamed, thermosprayed.
• Finally, establish evaluation methods, such as surface scraping and see the bacterial growth that may or may not be monitored through ultraviolet light lamps looking for organic matter.

The objective of the washing is to eliminate the bio film formed by the accumulation of fats which avoids the disinfectant from having contact with the pathogen.

The table above shows the intrinsic qualities of the different families of biocides. This information allows us to use each of the products based on their qualities, and it is clear that a disinfectant does not work for everything.

Disinfectants have limitations, so we must know how they act and which pathogens they eliminate. As an example, we can graph the efficacy of quaternary ammonium and glutaraldehyde and how they complement each other by joining them in a commercial product.

As it can be observed Ammonium Quaternaries have bactericidal activity and act trough a residual biofilm, and on the other hand, Glutaraldehyde also has bactericidal activity, but also acts on viruses and fungi. Joining them we have a complete product as seen in the following image.

It is important to know the residual effect of each of the biocides and to know the effective concentration in order to affirm that the product kill X or Z viruses or bacteria. We must know which protocol has been followed.

Another key point for the washing and disinfection process is the method of application. This will also depend on the product we want to use for disinfection, considering first the operator’s safety, and then, the operator must always use all the safety equipment required.

 

6. Animal batches with the same age

This issue is related to how we program our farm production and its direct effect on the group immunity and on the dynamics of the infections. We should use programs designed for production control and understand the use of the reports, so that, we can analyse and improve the production of the farm.

It is well known that based on the structure of the group we can modify the immunity against diseases, as well as the production and size of each batch.

This causes some problems in the production of the farm:

1. a) first time mothers or unproductive females are introduced to complete the birth groups
2. b) as births are increasing, we won’t have enough space for all the females, and we will have to group piglets

All the aforementioned issues will require more females and as a consequence the spaces will not be enough for the piglets, causing stress and immunosuppression in the animals.

In addition to lack of feed and reduction in water consumption. Vaccination and medication budgets will vary and, in some farms (which are managed by budgets), they will not have enough medication.

  

7. Vaccination and medication programs according to each farm and region

The objective of these programs is to eliminate or reduce the existing diseases in the region and in the farm. Programs must be comprehensive, that is, use all tools (vaccines, medicines, probiotics, additives, nutraceuticals, etc.) to minimize the possibility that the disease impacts the productivity and profitability of the farm.

In the following table we can see the frequency in the presentation of some swine diseases. This allows us to identify the most opportune moment of applying a vaccine or antimicrobial treatment.

In Mycoplasma control programs most of the effectiveness depends on the vaccine but programs also include some medication to mitigate the “errors� of vaccination. It is best to fight the problems from the mothers applying strong control programs in quarantine.

The vaccines must be applied following the laboratory instructions and do not use a lower dose to save money. In the case of antibiotics, use those that really comply with the standards rules regarding quality control, know their pharmacodynamics and give the required dose (milligrams per kg of weight, not kilos per ton), in addition to experiencing other medication routes (via drinking water). The important thing is to reduce as much as possible the negative effect of diseases on animal health.

 

8. Control of visits and people from outside the farm (wet and dry baths)

In previous, conferences we have been mentioned that human are the main vector of diseases in farms. Despite the installation of fully enclosed farms with air control, these have been infected because of humans.

It is mandatory that employees, veterinarians, visitors and owners take a bath if they are going to visit the farm, since we all are vectors of diseases. For this reason, we must keep the baths of the farms, as if they were those of our houses, that is, hot water, body and hair soap, clean towels, clean clothes, etc.

The guest book should never be missing, where the visitor’s name, date, time of arrival and departure, last contact with pigs, etc. are written down. This record will help us keep track of the visits and, in the event of any eventuality, to know their possible origin.

9. Control for mortality waste

Mortality is usually found in farm halls and necropsies are done inside the rooms or near the shed. This increases the possibility of contaminating other animals (it will depend on each disease). There must be a specific place for this purpose, with the appropriate material to be able to do the necropsy, as well as material for taking samples for the laboratory. If the veterinarian cannot do all the necropsies, it is necessary to train a person to do this work, detect the lesions found through photography and then analyze them by the specialist.

The mortality waste must be put into septic tanks, sanitary burial, incinerated or in composts, the important thing is that the animals are eliminated from the farm.

10. Waste management (stool, urine and water)

Waste management has an important environmental impact and also has a negative effect for the farm. The method used (biodigester, oxidation lagoons, oxidation lagoons with chemical methods, solids and liquids separator, etc.) should be friendly with the environment and neighborhood. Contamination of water and feed should be avoided.

As a result of the mismanagement of farm waste, we can incur the contamination of the water used for fed the farm. Therefore, it is necessary to make water quality analysis, and implement programs to chlorinate and ozonify drinking water to reduce the risk of contamination of the animals through water. It is important to have a tank with water in every shed to supply the animals. We can also use the tank to give medication or some additives by drinking water.

In the case of feed, it is important to analyse in order to check the presence of mycotoxins, and the source from which it comes (reliable or not). If we have contaminated grain, we must use mycotoxin binders.

 

11. Vehicle handling (washing)

Vehicles are one of the main ways of contaminations in farms. That’s the reason we must control the access of the vehicles on it.

In the State of Yucatán, a surveillance program is carried out in the control of entry into the State of vehicles for pig transport. Upon arrival at the state border, each vehicle must take the ballot that confirm that the service has be done at the washing and disinfection centre authorized by the producers. The vehicle is inspected by authorized personnel, if it meets the established requirements, it is given authorization to go to Yucatán to reload animals. If the vehicle does not meet the requirements, it must be washed again, imposing a fine to the transport operator.

In addition, it is mandatory that all vehicles that go to the surrounding area of the farm, pass through a sanitary arch properly built and prepared, so that, the disinfectant that is used has the needed effect.

On the other hand, it would be convenient to coordinate with the neighbors the schedules for the transport of the pigs that are destined for slaughter, those that move from one site to another of the same farms and the movement of the hoppers that carry feed and / or water to the farms.
It would be convenient to inform the feedmill that the vehicles must be washed and disinfected before bringing feed to the farms.

12. Laboratory of diagnosis

Laboratories of analysis are tools for the diagnosis of diseases, so it is very important to know the objective of each of them: ELISA, PCR, RT PCR, immunofluorecence, immunohistichemistry, histopathology etc. In addition, we must learn to interpret the results and use the information to establish integral infection control programs, determine when and what type of vaccine to use, determine what pathogens are affecting the farm at different ages. And thus, use the appropriate antibiotics and their form of application (via food, drinking water, intramuscular).