The latest trend in animal protein production is increased production under an animal welfare improvement scheme. In pig production, the use of alternative systems is a global trend that seeks to improve the quality of life of pigs within the pig facilities.

Within the alternative pig production, we have the deep bedding system. This system is popular in developing countries, which take advantage of second-use infrastructure such as poultry barn that have been abandoned or whose time of use has ended.

A deep-bed pig production system has been defined as one that provides the animal with the ability to select and modify its own microenvironment through bedding material such as hay, rice or coffee husks, corn husks, bagasse, wheat straw, rice straw, and soybean straw.

This substrate allows the pigs to perform natural activities of the species, such as rooting, which under natural conditions they normally do to dig up soil and dig up food from the ground.

Keeping pigs on a dry and soft substrate has been shown to reduce joint problems, lameness and foot rot. Far from thinking that wood shavings or sawdust would be good substrates, these are not recommended, as they are too thin and can cause respiratory problems in the animals.

As mentioned, unused poultry barn or systems can be adapted to establish a deep-bed pig system, however, two variants can be found:

– Tunnel type structure. They do not have heating means therefore, the animals keep their microenvironment, placing themselves inside the bedding material. They are based on an area of 1.1 m² per animal (COAFES, 1995; Gentry and McGlone, 2003).

– Hut-type structure. The animal density is around 1.4 m² to guarantee good use of the bedding and minimize management requirements. Most of these facilities come from the renovation and conversion of broiler barnbarn.

The importance of ventilation in pig production

Another important factor in deep litter systems is ventilation to ensure good air quality and reduce the risk of respiratory distress, disease and abnormal behavior. Dust, toxins, micro-organisms and harmful gases, including ammonia, hydrogen sulphide and methane from decomposing animal waste, can be problematic. Adequate, draught-free ventilation, particularly for young pigs, is important to effectively dissipate heat from the pigs and prevent the accumulation of effluent gases (mainly ammonia and hydrogen sulphide), including those from manure and dust in housing systems. A useful indicator is that if air quality at the pig level is uncomfortable for people, it is very likely to be a problem for the pigs.

This technology is economical; since locally available materials can be used for its construction, water is saved and there is no need to treat the waste (González, 2009; Galindo, 2007).

Management of porcine farms

Important aspects to emphasize in bed management include type of bed, quantity, quality, depth and maintenance. The goal is to have three shifts (groups of pigs) in the bed before cleaning the house. Adding clean, dry bedding on a regular basis will help keep the house dry, with less odor, so that the goal of three shifts can be achieved. Approximately three 30 kg bales of bedding per pig are required for each shift or group. More bedding may be required for the first shift and less for the next two shifts. The quality of the bedding is important for water absorption and the health of the pigs.

It is very important to start with dry bedding and not use wet products as moisture provides an environment for fungal growth, which can cause health problems for the pigs. Moisture can be reduced by placing the drinking system outside the litter area; also, we must be careful about the number of feeding centers in each house or pen. Too few feeding centers causes too much activity around each trough, resulting in bedding deterioration and excess moisture in the bedding.

Bedding depth is critical for favorable results, and it is desirable to start at least 30 to 45 cm deep, since all bedding materials perform better the deeper, they are (Honeyman and Kent, 2001; Mancipe and Chaparro, 2008; Cruz et al., 2009).

Benefits of the deep bed concept in pigs

The best results are obtained if fresh and dry bedding is added weekly, or at least, if it is added in the wet and dirty parts that appear in certain areas of the corrals (defecation areas).

It is an environmentally friendly system that requires minimal waste emission; it also considerably reduces odors and the presence of flies, provides excellent quality fertilizer and an alternative source of feed for ruminants (González, 2005; Cruz et al., 2010).

It is a system that increases the welfare of pigs, since there is less or no aggression between animals, allowing them to better express their behavior, decreasing mortality and increasing homogeneity in the lot.

Bibliografía:

• College of Agricultural, Food and Environmental Sciences (COAFES). 1995. Hogs your way. Choosing a Hog Production System in the Upper Midwest. University of Minnesota Undergraduate.
• Gentry JC, McGlone JJ, Blanton JR Jr, Miller MF. 2002. Alternative housing systems for pigs: Influences on growth, composition, and pork quality. Journal of Animal Science 80(7): 1781-1790.
• Galindo SLR. 2007. El sistema cama profunda. Asociación Argentina Cabañeros de Porcinos.
• González CA. 2005. Sistemas alternativos de producción de cerdos en Venezuela. En: Sistemas Integrados de Producción con no Rumiantes. Caracas, Venezuela: Instituto de Producción Animal, Facultad de Agronomía, Universidad Central de Venezuela.
• Honeyman M, Kent D. 2001. Performance of a swedish deep-bedded feeder pig production system in Iowa. American Journal of Alternative Agriculture 2: 50-56.
• Mancipe EA, Chaparro CH. 2008. Descripción y diseño de un modelo para la producción de credos de engorde en el sistema de cama profunda (en clima frío) con base en la experiencia de tres granjas porcícolas en el departamento de Cundinamarca [tesis de licenciatura]. Bogotá, Colombia: Universidad de La Salle.
• Cruz E, Almaguel RE, Mederos CM, Araujo CG. 2009. Sistema de cama profunda en la producción porcina a pequeña escala. Revista Científica 19: 495-499

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