Producing pork meat more efficiently requires a precise control of all the factors that can affect production performance. Ventilation in pig farms is one of these factors, since a proper ventilation system will have a positive impact on animal welfare and farm profitability.

The objective of on-farm ventilation systems, is the movement and permanent renewal of the air. In this way it helps to evacuate harmful gases (CO2, ammonia), bad odors, dust and keep both, temperature and humidity controlled, in normal levels.

Types of ventilation in Pig farm

First, we can differentiate between 2 basic ventilation systems: natural (static) and forced (dynamic).

Natural ventilation (static)

This type of ventilation combines both air flows and wind speed. The temperature difference between the indoor and outdoor of the farm causes air movement, and hot air is usually on the roof of the building generating a negative pressure that facilitates the entry of cold air from the outside.

Natural ventilation is also generated by the pressure exerted by the wind moving through the lateral and upper orifices of the building. Another example of an installation with natural ventilation is the wind tunnel, which requires less investment. It is provided with a ventilation orifice at each end; it is oriented in the direction of the prevailing winds.

The disadvantage of this type of ventilation is that it cannot be controlled. If the climatic conditions do not generate enough temperature difference between the inside and the outside of the farm, the air movement would be insufficient and inefficient, and this will lead to temperature and air quality problems.

Forced ventilation (dynamic)

Forced ventilation systems are provided with some mechanical elements (fans, extractors) to generate a controlled dynamic air flow. In this type of ventilation 3 systems are used:

• Neutral pressure
• Positive pressure
• Negative pressure

Neutral pressure system

These systems have fans that force the entrance of the air inside the building, and extractors that promote the air out.

The wind cannot exert a direct influence on this type of system, which generally consist of vertical ducts that distribute the air in different directions. The configuration of the interior ventilation orifices is important to avoid direct air currents towards the animals.

In certain installations, a slight negative pressure must be generated to avoid condensation. Also, air mixers are usually incorporated, which prevent the outside air from entering at very low temperatures in winter.

Positive pressure systems

This system includes forcers that facilitate the entry of air into the building, while the air leaves through ventilation orifices located at different heights of the farm. This type of installation is used in completely closed buildings, and currently it is not widely used because it has problems with humidity control, which generates excess condensation and deterioration of structures.

Negative pressure systems

They are the most widely used systems today. They have air inlets located at the top of the walls and the air comes out through extractors located in the ceiling. Another configuration of this system is characterized by extractors located in the lower parts of the walls or under slats, and in this way a better control of harmful gases is achieved, especially ammonia.

It is important to design the system so that the air entries are at the top of the building, so that the cold air from the outside mixes with the warm air from the inside.

These systems are more and more widespread because they are very energy efficient, and allow a good control of temperature, humidity, and air quality.

Finally, the specific needs of the ventilation system must also be calculated, as well as to determine the air flow to be moved within the installation. It is recommended for fattening pigs to move a flow of 120 m³ per 100 kg of live animal.

How to complement ventilation with natural additives to improve ammonia control?

One of the main objectives of ventilation is the elimination of harmful gases such as ammonia, which is a gas that generates negative effects on productivity, and causes respiratory problems in animals and workers, and accelerates the deterioration of the building. In certain situations, ventilation does not achieve optimal ammonia control, and the use of additives specially designed for this problem becomes necessary.

Eliminating ammonia from the building through ventilation is not the only strategy that must be applied, and we must reduce its production. The simple elimination means transferring the problem to the environment. Ammonia is a polluting gas that affects human health, and its smell causes social problems.

To reduce ammonia production on farms, Biovet SA has developed a specific solution based on a combination of saponins, phenolic compounds and the cimenol ring (Alquernat® Yucca).

Saponins and phenolic compounds are present in Yucca extract. Saponins control ammonia thanks to different characteristics:

• Antimicrobial effect (limited) against ammonia-producing microorganisms.
• Inhibition of ureases (that transforms urea into ammonia).
• Surfactant effect that helps in the antimicrobial action and in the absorption of nutrients.
• Ammonia- binding effect, preventing it from volatilizing.
• Stimulation of organic acid-producing microorganisms that react with ammonia, forming less toxic salts than the original compound. In addition, these microorganisms neutralize alkaline waste from animals, thus reducing the volatility of ammonia.

Phenolic compounds have reactive radicals that can bind ammonia, transforming it into less toxic compounds.

One of the keys for reducing the production of ammonia is to control the bacteria that produce this gas. For this reason, Alquernat® Yucca incorporates cimenol ring (botanical molecule) that has an antimicrobial action greater to that of saponins. The combination of these active principles is a differential value that makes Alquernat® Yucca unique compared to other tools with similar purpose.

Conclusions

The ventilation of the farm requires a detailed study of the needs of each farm. Poor air movement will have negative consequences on air quality, temperature, and humidity.

The type of ventilation to be implemented will depend on the degree of modernization of the farm, geographical location (climate), type of animals, among others.

Comfort and animal welfare are increasingly monitored and measured in animal production, and ventilation allows us to improve these aspects.

In order to control ammonia levels, we should implement strategies that combine ventilation systems and natural additives, such as Alquernat®Yucca, that reduces ammonia production. This is especially important in cold seasons, when ventilation is reduced for a better control of the temperature, as well as in other situations that require additional support to improve air quality.

Alquernat® Yuccais able to inhibit ureases (by transforming urea into ammonia), bind ammonia, improve nutrient absorption, and control ammonia-producing bacteria. As long as the air quality is improved, the productive parameters are improved.

Alquernat® Yucca is a product manufactured and marketed by Biovet S.A.

Bibliographic references:

• J Pie, 2021. Conferencia: Reducción del amoníaco ambiental para mejorar la productividad con Alquernat Yucca. Disponible en: https://www.veterinariadigital.com/
• Wenke, J.Pospiech, T.Reutter, B.Altmann, U.Truyen, S.Speck .Impact of different supply air and recirculating air filtration systems on stable climate, animal health, and performance of fattening pigs in a commercial pig farm. Disponible en: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0194641
•  D.Diez, 2019. Importancia de los niveles de amoniaco ambiental y su control mediante Alquernat Yucca. Disponible en: https://www.veterinariadigital.com/articulos/alquernat-yucca-control-niveles-amoniaco-ambiental/
• M.Soriano, 2021. Claves para reducir los niveles de amoníaco en la granja y mejorar el bienestar y rendimiento animal. https://www.veterinariadigital.com/articulos/claves-para-reducir-los-niveles-de-amoniaco-en-la-granja-y-mejorar-el-bienestar-y-rendimiento-animal/