Biosecurity is no joke. Most practitioners are aware of its significance considering the media focus on bovine viral diarrhea
(BVD), bovine spongiform encephalopathy and agroterrorism. Yet veterinarians who are known to make a host of producer safety
recommendations often omit some security suggestions because they appear excessive.
However, it's the more extreme measures that stress the seriousness and importance of strict farm biosecurity and might make
producers wake up to the fact that this is not a trivial matter. When it comes to securing the nation's food supply, a recent
meeting on disease risk management by the Center for Food Security and Public Health at Iowa State University provides a
wealth of information. The agency offers fact sheets on biosecurity, foreign animal diseases, zoonoses, disinfectants and
much more. It also creates tools for farm assessments in the name of disease prevention.
Biological risk management
Although much focus is placed on foreign animal diseases such as foot-and-mouth disease (FMD), practitioners know many domestic
diseases routinely pose problems for producers, and each disease has distinctive characteristics when it comes to management.
The task of preventing many diseases simultaneously can be overwhelming for producers. However, if approached from the route
of transmission perspective, it becomes simpler. If all possible routes of transmission are managed, prevention of all diseases,
whether foreign or domestic, can be managed.
Routes of disease transmission
Some of the routes of transmission are common and easy to remember. Others are easily overlooked, so it helps to review how
- Aerosol: Droplets are passed through the air from one animal to another.
- Direct contact: The disease agent touches open wounds, mucous membranes or skin through blood, saliva, nose-to-nose contact, rubbing or biting.
Reproduction is a subtype of direct contact that includes a disease's spread via mating or to the fetus during pregnancy.
- Fomite: An inanimate object carries a disease agent from one susceptible animal to another. Traffic is a subtype of fomite transmission
in which a vehicle, trailer or human spreads organic material to another location.
- Oral: This involves consuming disease-causing agents in contaminated feed, water or licking/chewing on contaminated environmental
- Vector-borne: An insect acquires a disease agent from one animal and transmits it to another.
The following recommendations are aimed at preventing the entry of disease as well as monitoring and prevention in case of
a biosecurity breech.
Animal identification, herd records
Most producers have some experience with animal identification and record keeping. Animals should be individually identified.
Currently available individual identification tags include orange and silver metal clips used for years for regulatory work
as well as electronic identifications. A dangle tag number 12 or ear tattoo R106, for example, are not individual. Individual
identification helps prevent any mix-up of animals, and the best option is a dangle tag that is easily seen and is cross-referenced
with the individual tag. That way if one falls out, the animal still has some identification.
This system allows the producer to keep better production and health records. It's also needed to record animal movements
on and off the farm. Herd introduction dates, where the animal was purchased and its origin, movements on and off the farm
and in between units should be recorded.
Farm disease monitoring, control
Practitioners should review the nutrition and vaccination programs of herds to boost non-specific and specific disease immunity.
Encourage producers and their employees to clean equipment and change clothing between groups of animals and when returning
from another farm. Observation of animals for signs of disease, prompt treatment and necropsy of animals that die or are euthanized
are important for early recognition and prevention of possible disease spread. Producers should limit new introductions and
animals traveling off the farm for shows and sales then returning as much as possible. A quarantine area should be set up
for these animals as well as sick animals.