Disinfection and effective cleaning in pig farms
Cleaning and disinfection are part of biosecurity programs implemented in swine facilities in order to prevent the entry, reverse the spread and minimize the risk that may pose a pathogen, both for animals and for farm staff.
Pig farms are permanently under the threat of entry and spread of pathogens. The explosion of an outbreak of an infectious disease, especially if it is a notifiable disease official statement, in addition to the commitment to its viability, is a source of risk for other animal species and even humans if the responsible agent is zoonotic.
Bacteria and fungi can survive, and some multiply on wet surfaces, especially if there is organic matter.While most bacteria are labile and fragile exceptions such as mycobacteria and sporulated bacilli resisting hostile conditions. Similarly, the behavior of pathogenic microorganisms against chemical compounds is variable, depending on the type of differences cell wall and spore forming ability. In any case, as with antibiotics, they have also been described resistances. Viruses, which are unique in their dependence on living cells, some are resistant to the environment and can survive long periods, as with parvovirus.
Until a few years ago, the practices we know today under the name comprehensive biosafety were not sufficiently valued. The professionalization of the production sectors and scientific studies demonstrating its utility sectors have made themselves and administrations include national programs, often mandatory for the control and eradication of many infectious diseases. Biosecurity includes a set of measures that are intended to prevent the entry of pathogens on a farm and, as the case may slow or prevent its spread in her and other neighbors, as well as minimize the risk (if any) for employees. The cleaning and disinfection practices are main part of the programs and every day more important.
Cleaning as a preliminary step
Cleaning and disinfection are inseparable phases of hygiene in pig farms. On farms are unusual circumstances (walls, floors and ceilings rough surface, abundance of organic matter, low temperatures, etc.) which represent limiting factors for the action of disinfectants, requiring minimize its negative effect to achieve favorable results. For this reason, pre-cleaning disinfection is critical in it.
As WHO (1994) noted, they can be considered two general systems for cleaning: dry and wet. In any case, the process begins by cleaning the fans (where they exist) and air intakes. After bedding and manure floor or cages are removed, without neglecting the corners, ribbons manure collection and final wells.equipment (cages, feeding, watering, etc.), collects the accumulated matter and all material outside the barn is transported dismantled. On the outside, over an area of concrete proceeds to washing with high pressure washing vancouver wa water, followed by drying and disinfection. Inside, brush, sweeps and vacuums to remove dust and dirt from ceilings, electrical installation, beams, cornices, walls, cages, parts of fans, air intakes and corridors, all in up-down and back -ahead. Fouling scratch by hand with a wire brush.
In order to save costs (labor and time), on farms cleaning with high pressure water cleaning in two phases often used, and soaked. Soaking is wetted with water (1L / m2, 1-2 h). Sometimes liquid detergents are added. In cleaning itself cleaners are used at pressures of 10-100 bar, at a distance not less than 40 cm from the surface. It is more effective than cold hot water. On wood or concrete surfaces, poor conductors, the optimum temperature is 40 ° C, while higher temperatures metal surfaces can be used, with best results if the application time on the surface is sufficiently long. The recommended flow is 600-800 l / h if cold water can reach 1,100. The use of pressurized water can generate secondary aerosols that cause hazardous situations if there has been an outbreak, particularly if zoonotic agents are involved, so precautions should be taken.
After cleaning, leave the plants dry. If devices are provided for this, heating and ventilation to facilitate water evaporation alternate. Drying reduces pollution, at least one log cycle, especially gram-negative microorganisms.
Depending on the type of material, cleaning can reduce 3 log or more of the total bacteria count, as they reduce the effective disinfectant, which means that under normal conditions, per cm2 of farms, can stay around 103 ufc, usually sporulated agents.
Disinfection and disinfectants
Disinfection process is capable of removing pathogenic microorganisms by chemical or physical agents.Usually sporulated forms survival allowed. A disinfectant is a biocide (Directive 98/8 / EC and RD 1054/2002). Disinfectants for veterinary hygiene correspond to the type of product (TP-3) within the main group 1. They are used in areas where they are housed, they kept or transported animals, to disinfect teats in cows, footwear and hatcheries. The TP-3 covering the use of disinfectants to control animal pathogens to prevent infectious diseases, to increase (indirectly) production and improve production and quality of products of animal origin.
The choice of disinfectant is important. In general, in the case of outbreaks of notifiable diseases, often pure substances of activity tested against the causative pathogen used, while non-specific preventive disinfection using commercial formulations of broad spectrum include various compounds or combinations and their effectiveness depends on the concentration of use. All recommendations should be based on laboratory data.
Disinfectants used in animal farms can be grouped into:
An ideal disinfectant should be: soluble in water, broad spectrum, active in the presence of organic, stable material, non-toxic, fast acting, with residual, penetrating, compatible with all materials action, which does not affect the environment, available and good value for cost-risk-benefit.
In general, for disinfecting a surface in a warehouse, it takes at least 0.4 l / m2 and equipment is recommended to add 30% more. The effectiveness of disinfection depends on the disinfectant and microorganism to which the practice is addressed, as well as other characteristics that influence both as resistance and survival of the agent, the ability to multiply, the concentration of disinfectant contact duration, ambient temperature, etc. The optimum temperature for liquids used in the cleaning and disinfecting farms is 40 ° C and for the surfaces of 20 ° C. Colder requires higher concentrations; below 10 ° C, the disinfection effect is incomplete. Humidity and air velocity negatively affect most surface disinfectants.
Disinfection should be performed in the same order as wet cleaning, that is, from top to bottom and back to front of the building. It is advisable to know the nature of the surface of the floor, ceiling and walls, to correctly apply disinfectants. The contact time with the surface can vary depending on the type of disinfectant used. Should follow the manufacturer’s recommendations contained in the label.
For application, various methods can be used, including the use of:
In any case, after the exposure time, allowed to dry installation, disinfectant residues are removed and food and water bowls ready before guards are removed. It is recommended to verify the effectiveness with the help of the laboratory. Before repopulate, allowed to “rest” the barn about a week with ventilation.
Transport vehicles are difficult to disinfect, especially in cold weather. disinfection in a separate shed and a minimum temperature of 10 ° C is recommended. Should be cleaned with hot water and excess liquid must be removed by a vacuum cleaner. The concentration of the disinfectant must rise at least three times.The effect is enhanced if carried out a preliminary disinfection before cleaning. The process takes place in four phases:
Usually we proceed to disinfection of facilities and equipment when the warehouse is emptied, cleaned and washed, as with the other materials. Such a situation occurs, optimally, in the course of production systems all in-all out during the resting phase or as a result of bound by an outbreak of an infectious disease depopulation. Optionally, it may be convenient to carry out a plan of environmental disinfection on the warehouse occupied by livestock, in which case it will have a significant impact on the pre-disinfection process, the chosen disinfectant and the method of application. In such circumstances it is impossible to complete cleaning and disinfection before the disinfectant used must be non-toxic and possess biocidal effect when applied as a mist or spray. chemicals that work well in these conditions include for example phenylphenols, hexylresorcinol, resorcinol, cloroxifenol, propylene glycol and trimethylene.
In the case of solid waste (manure) and liquids, particularly when there have been outbreaks of infectious diseases, disinfection task is more complicated. For liquid (slurry) you are required to have equipment that enables efficient distribution and mixing of disinfectant, which must be kept at least one hour. Table 2 lists some recommendations of disinfectants and concentrations for different pathogens. Once disinfected, the slurry can be spread on arable land at a rate of 30 m3 / ha. The solid manure can be treated with burnt lime to get hot enough to sanitize, given that modern operating systems that do not use straw or it is scarce, not efficient thermophilic microorganisms selected for the self-heating.