Table of Contents

1. Overview

People don’t think of the far-reaching consequences of an action like bringing fruit illegally across the border, or of buying unmarked pigs at an auction. It might be out of innocence and ignorance that biosecurity measures are flouted, but the revenue lost can amount to billions of rand which can bring a whole sector to its knees – and threaten the livelihoods of thousands.

Biosecurity analyses and manages risks in the sectors of food safety, animal and plant life and health, including the associated environmental risk. It encompasses the policy and regulatory frameworks.

Investing in its capacity to control disease and to protect its food systems is in a country’s interest. Biosecurity is a national and regional issue.

 

2. Biosecurity and the livestock farmer

For detailed and specific information about applying biosecurity principles to your operation, consult your veterinarian or the relevant commodity/trade association e.g. the Red Meat Producers Organisation (RPO) and National Emergent Red Meat Producer Organisation (NERPO), whose notes on precautionary measures to protect your herd against diseases acquired because of external contact can be found here.

While developing and maintaining biosecurity is difficult, it is the cheapest, most effective means of disease control available, and no disease prevention programme will work without it.

Infectious diseases can be spread between operations by:

  • the introduction of diseased cattle or healthy cattle incubating disease
  • introduction of healthy cattle who have recovered from disease but are now carriers
  • vehicles, equipment, clothing and shoes of visitors or employees who move between herds
  • contact with inanimate objects that are contaminated with disease organisms
  • carcasses of dead cattle that have not been disposed of properly
  • feedstuffs, especially high risk feedstuff which could be contaminated with faeces
  • impure water (surface drainage water, etc.)
  • manure handling and aerosolised manure and dust
  • non-livestock (horses, dogs, cats, wildlife, rodents, birds and insects)

Biosecurity has three major components: Isolation, Traffic Control, Sanitation.

  1. Isolation: The most important step in disease control is to minimise commingling and movement of cattle.
  2. Traffic control includes traffic onto your operation and traffic patterns within your operation. It is important to understand traffic includes more than vehicles. All animals and people must be considered. Animals other than cattle include dogs, cats, horses, wildlife, rodents and birds.
  3. Sanitation addresses the disinfection of materials, people and equipment entering the operation and the cleanliness of the people and equipment on the operation.
Source: adapted from Biosecurity Basics for Cattle Operations and Good Management Practices (GMP) for Controlling Infectious Diseases, published by Institute of Agricultural and Natural Resources, University of Nebraska-Lincoln Extension 

 

3. Zoonoses: diseases of livestock that can affect humans

The word zoonosis has its origins in the Greek zoon, meaning animal, and nosos meaning disease. In 1959, the World Health Organisation Expert Committee on Zoonoses, defined zoonoses as “those diseases and infections that are naturally transmitted between vertebrate animals and man”.

Zoonotic diseases are an occupational hazard for all those who work with livestock, including farmers and their workers, veterinary staff, those in the abattoir and dairy industries and, ultimately, the consumers of animal products like meat, dairy products and eggs.

Preventing the transfer of zoonotic diseases from animals to humans rests on three pillars. The first of these is keeping animals healthy through good management, vaccinations and parasite control. The second pillar is personal hygiene and attention to healthy working conditions in the livestock industry – particularly details like the provision of good ventilation and accessible ablution blocks. The third pillar is food hygiene, maintaining a cold chain and the inspection and quality control of animal products from the farm to the table. If these three pillars are kept in place, the chance or risk of catching any disease from an animal is very low – you are much more likely to catch diseases from other people! Prevention is better than cure; however, if you suspect you have a zoonotic disease, it is advisable to consult a medical practitioner as soon as possible.

Further details on the symptoms and treatment of zoonotic diseases are obtainable on the World Health Organisation (www.who.int) and the Centers for Disease Control and Prevention (www.cdc.gov) websites.

The following table, used courtesy of Prof CME McCrindle (Faculty of Veterinary Science of the University of Pretoria), summarises the most important zoonotic diseases of livestock and gives some idea of how to prevent them being transmitted.