Microorganisms mainly live inside biofilms, an exopolysaccharidic matrix (EPS) they build around themselves as protection against attack.
In the biofilm we can find:
- persistent bacteria suddenly revived after being dormant for several months
- resistant pathogens that will re-contaminate the environment
- the most important part of the microorganism's biomass
Trying to disinfect the surfaces without first breaking the biofilm is useless. The best and most economical way to break a biofilm is to use detergent.
To be effective in livestock buildings, detergents must have these five essential characteristics:
1. Surfactive properties
Surfactants are the most important element of cleaning products. They have a hydrophilic (water-loving) and a hydrophobic (water-repelling) end. As illustrated in Figure 1, these opposing forces help to reduce surface tension, and remove and disperse organic material.
Surfactants also act as wetting agents. Wetting power is the ability of a liquid to penetrate the organic matter and the biofilm, to break cohesion and facilitate elimination. Water alone does not have a high wetting power because the surface tension of water is relatively high compared to other liquids (Figure 2). But when water is mixed with a detergent, and its surfactant properties lower the surface tension, better penetration and therefore cleaning can be achieved.
The foaming power of the detergent is also important. The foam helps the user to see the spray and achieve good coverage. But the quality of the foam must be adapted to each environment. In livestock buildings, the foam must remain fluid enough to penetrate porous surfaces and biofilms in 15 to 30 minutes.
2. Raise the pH
Detergents used in the livestock industry must be able to deal with organic matter. The best degreasing and biofilm (EPS) removal products are achieved by alkaline detergents which combine soda (NaOH) and potassium hydroxide (KOH).
3. Active in hard water
Chelating agents in the detergents ensure that optimal activity is maintained, even in the presence of hard water. Water hardness, or to use its full scientific name, the hydrotimetric titre of water (TH), depends on the concentration of calcium and magnesium ions.
4. Have bactericidal and virucidal activity
Specific products such as DT Move(R), in addition to being a detergent, decontaminate surfaces and the rinsing water. This is an added bonus in reducing cross contamination.
The product should be biodegradable in order to achieve certification for use in certain production systems including organic farming (Ecocert).
A detergent that possess all five of these characteristics can be used reliably in livestock buildings as part of the biosecurity cleaning protocols.