Biosecurity is the set of sanitary practices designed to limit introduction, circulation and persistence of contaminants(pathogens that cause diseases) in the production unit, in addition to their spreading to other production sites. In dairy cattle breeding, Biosecurity mainly involves management of the building and one of its aims is to reduce the use of antibiotics on the farm.
Ensuring the health safety of the animals first of all entails properly fitting out and designing the animals’ living areas, as well as guaranteeing their comfort, but also the cleanliness and atmosphere of the buildings (temperature, air quality, hygrometry and lighting).
The layout of the building and its immediate vicinity must be taken into account in preventing risks of contamination. The surroundings of the buildings must be clean and well maintained (no waste stored along the walls) to avoid harbouring pests (rodents, birds and insects).
Organisation of dairy farming is divided into two zones:
The living zones must be maintained daily (raking, strawing); it is the work zones that carry the greatest risk. They must therefore be subject to extensive health measures.
The organisation of the flows also offers a simple means of reducing pressure in terms of health on a farm. Work should be performed so as not to cross a “contaminated” circuit (everything originating from outside) with a “clean” circuit (the zone in which the animals circulat and live). The “contaminated” circuit will group together deliveries, trade, equipment (particularly if shared) and outside personnel. All these elements pose risks and must therefore be paid particular attention.
The drinking water intended for the dairy cattle is not subject to any legislation setting quality standards, unlike water for human consumption, which is required to fulfil potability criteria. The regulations solely stipulate that it should be of “adequate” quality, and to meet this requirement, a certain number of criteria are defined.
Although no established standard exists, it is recommended to test for the absence of microorganisms (total Coli, E. coli, streptococci, etc.) in 100 ml of water.
Contamination may already occur at the water catchment point, but also in the farm piping, particularly owing to the residual biofilm . In order to ascertain the bacteriological quality of the water, an analysis should be carried out (ideally at the airlock and at the end of the line). In the event of inadequate bacteriological quality, it is recommended that corrective measures be taken: checking the watertightness of the catchment point and implementing water disinfection (chlorine dioxide, hydrogen peroxide or chlorine).
It is essential to be aware of the physical and chemical quality of the drinking water, as under certain circumstances, it may cause:
A physical and chemical analysis of the water should be carried out at least once every 2 years.
Purging under pressure is essential during the cleaning operations to achieve a sufficient mechanical flushing effect in order to wash out the impurities removed from the piping walls by the cleaning products.
The standard procedure for cleaning the inside of the pipes to remove as much biofilm as possible is as follows:
In dairy farming, the Cleaning & Disinfection programme primarily concerns the milking parlour, the calving zone, the calf rearing area and the sick bay.
The breeding system does not in fact allow implementation of this programme on a regular basis.
In the event of a health situation, however, it is a practice that proves effective and worthwhile.
Special care must be taken in the calf rearing area in case of diarrhoea..
Disinfection of the premises combined with the animal health programme should make it possible to restore a good balance to the farm.
This operation serves to give the surfaces a visually clean appearance. A detergent of foam type should be used, which achieves a better scouring effect.
Organic matter (straw, droppings) inhibits the action of the disinfectants. The success of disinfection is thus influenced by the thoroughness applied to the cleaning process.
A good washing beforehand with a suitable product already achieves 70 to 80% of the decontamination by means of the “flushing” effect.
This is the first disinfection operation after washing the building. It is usually carried out by spraying the previously cleaned surfaces.
There are risk factors in a badly performed spray disinfection:
The equipment used for decontamination
The use of a foam gun makes it easier to apply the disinfectant, provided that a foaming product is used. When applied in foam form, the disinfectant is more effective. Indeed, the foam allows the product to achieve better adhesion to the surface, thereby increasing the contact time and therefore the efficacy of the decontamination. The product employed must comply with the currently applicable legislation (mandatorily category TP3).
For operator safety, protective measures are indispensable during operations involving Cleaning & Disinfection.