In agriculture, biosecurity refers to procedures to reduce the risk of infectious diseases being transmitted amongst animals.
It is an important factor in the livestock industry. Symptoms of a disease may not always be obvious, especially in the early stages of infection. This makes it necessary to apply biosecurity measures on an ongoing basis.
By having a comprehensive biosecurity programme on your farm, you can:
- prevent the spread of disease;
- improve animal welfare by keeping more animals healthy;
- identify disease early;
- reduce the costs of disease prevention and treatment;
- help to ensure that you produce high-quality, safe products;
- increase your chances of running a successful business.
How diseases are spread
The first step to achieving biosecurity is understanding how diseases are spread. This can be through direct transfer, where one animal transmits the disease to another (through nasal discharge, for example), or indirect transfer, where equipment or objects contaminated with the disease carry the disease to an animal.
Disease in cattle can be spread through the following:
- Diseased cattle or healthy cattle that incubate the disease;
- Other animals, such as livestock, pets, wild birds and vermin and insects;
- Contaminated clothing and shoes of visitors and employees, farm equipment, and vehicles.
- Contaminated feed, water, bedding and soil;
- The carcasses of dead animals;
- Airborne particles and dust blown by the wind.
Farmworkers provide the first line of defence against the spread of disease.
They should therefore perform the following tasks:
- Ensure that all equipment that enters and leaves the farm is clean, as it can carry disease from farm to farm;
- Restrict access to certain areas;
- Clean and sanitise implements such as hoof-trimming tools and calving chains. These should be scrubbed with a brush to clean off all dirt and debris, otherwise disinfectants will not be effective;
- Wear clean clothes to work daily. Dirty clothes should be washed in very hot water and tumble-dried if possible;
- Ensure that footwear is clean and dirt-free. Disinfect when moving from one pen to another, especially after working in pens with sick animals;
- Wash hands frequently and thoroughly;
- Be aware of visitors, and inform the supervisor of strangers on the farm. Ask visitors to report to the office or owner;
- Keep the feed-storage area hygienic. Clean it before restocking and destroy all contaminated feed;
- Repair fences immediately to keep wildlife and other animals out.
It is crucial to monitor the health of the herd daily, and report any sign of illness to your veterinarian or extension officer. Proper identification will ensure that sick animals can be traced.
A key part of herd health is to carry out an annual vaccination programme; this will help protect cows from disease and infection.
Keep different age and production groups in different camps and isolate new animals. If they are ill, treat them immediately.
Finally, if you run a dairy farm, milk cows with mastitis last, and disinfect the parlour after use.
Source: The Milk SA Guide to Dairy Farming. 2014. Milk SA and AgriConnect.