Biosecurity: Your First Line Of Defence Against Disease

Dr Fambies van Biljon, veterinarian at Sovereign Foods, talks to Glenneis Kriel about the crucial need to establish a well-run biosecurity programme at a poultry production facility.

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Why is biosecurity so important? Why can’t birds simply be medicated when they fall ill?

The problem with poultry production is that many avian diseases, such as avian influenza and Newcastle disease, have no cure. So the best strategy is to prevent these diseases from entering your farm in the first place through a good biosecurity and sanitation programme.

The worldwide movement against the use of antibiotics due to rising fears over antimicrobial resistance is also putting pressure on farmers to use more preventative control measures. Even here in South Africa, cases of E. coli resistance have been reported for certain antimicrobials. Antibiotics should be used only as a last resort, and then as prescribed by the veterinarian who identified the disease.

What about vaccines?

These are widely used for most poultry diseases, but currently vaccines for highly pathogenic avian influenza (HPAI) are not registered for use in South Africa due to fear of negative consequences for international trade. In addition, there are concerns that vaccination would mask a future outbreak. It would be difficult in any case to vaccinate against HPAI as vaccines are strain-specific: no single vaccine covers all cases of HPAI. Local producers prefer to destroy chicken populations that have become infected.

HPAI vaccines are, however, widely used in countries where the disease has become endemic, such as China and Egypt. In addition, vaccines are not foolproof, as birds can still contract a disease after vaccination. There are several reasons for this: the vaccine might have been stored or administered incorrectly; the dosage might have been wrong; the medication might have been past its use-by date; or the birds might have had weakened immune systems, or been stressed or already infected when the vaccine was administered.