Biosecurity on the Farm: The Basics
What is biosecurity and why does it matter?
With the COVID-19 pandemic first and foremost in our minds, disease spread is currently a hot topic. Managing the risks of disease and preventing transfer, however, has been part of agricultural life for many decades. Simply put, biosecurity is the prevention of disease or contamination through practical measures. These can be anything from making sure you always wash your hands properly, to using foot dips and quarantining stock.
Biosecurity is a vital part of agriculture. There are many diseases that can have significant impact on livestock and crops. Preventing spread of these diseases is paramount. Proper biosecurity protects not only the animals and crops on your farm, but also staff and visitors. It also benefits the wider agricultural community and helps to avoid outbreaks and epidemics.
How do diseases spread?
Primarily, diseases spread in two different ways. Transmission can be direct or indirect and how a disease moves around influences the measures needed to control it.
In direct transmission, disease passes directly from one infected host to another. This can be through:
For example, a single infected animal in a herd might pass the disease to the animals around it. In zoonotic diseases, like bird flu, animals can pass disease to people and other species, or vice versa.
- Droplet infection
This is when the infected host sneezes, or coughs, and produces droplets contaminated with the disease. Most colds and coughs spread in this way.
- Body fluid
Contact with infected bodily fluids such as blood, milk, faeces, or saliva can spread disease. Transplacental infection also falls under this category, as disease is passed from mother to offspring through transfer of bodily fluids in utero.
In indirect transmission, the disease passes from an infected animal to a vector, and then to a new host. On a farm, the main sources of indirect transmission are:
- Pests and insects
Invertebrates are common vectors of disease transmission. In human populations, mosquitoes are notorious for their role in transmitting dangerous diseases like malaria and Zika virus. Similarly animals are at risk from diseases like Schmallenberg virus and babesiosis. Many parasites go through invertebrate hosts, like ticks, before infecting animals, so preventing these can go a long way in avoiding parasite infection.
- Food and water
Contamination in feed or water is a serious risk. For example, in the early 1990s, the UK suffered from a severe outbreak of bovine spongiform encephalopathy (BSE). Scientists identified that the disease was primarily transferred through animals eating feed containing meat-and-bone meal from infected livestock. Other diseases can spread this way such as toxoplasmosis and sarcocystosis, and diseases like cryptosporidium and giardia are transmitted in water.
- Equipment, machinery, tools and clothes
Contamination on materials can spread disease from one animal to another. During the Foot-and-Mouth outbreak of 2001 in the UK, strict biosecurity measures were in place to reduce disease transmission. These included mandatory disinfection of all vehicles in agricultural areas.
What biosecurity measures should I take?
There are a wide variety of biosecurity methods and many of these can be increased or intensified if diseases are known to be present.
Personnel and visitors
- Wash hands regularly and provide adequate sanitation facilities
- Provide boot dips with sufficient disinfectants
- Make sure all staff are trained in biosecurity procedures
- Keep visitors to a minimum and make sure they follow biosecurity measures
- Avoid wearing the same clothes and footwear off-farm, especially if you are likely to come into contact with other livestock
- Communicate with neighbours and the wider community
- Ensure prompt and accurate reporting of any notifiable diseases
Equipment, buildings and vehicles
- Keep vehicles clean, inside and out
- Disinfect trailers, tractors, and other vehicles regularly
- Keep buildings clean and make sure indoor animals have fresh bedding
- Clean and disinfect buildings and equipment after use
- Make sure any shared or hired equipment is cleaned before use
Moving stock and management
- Know the health status of any livestock you buy
- Isolate new stock before integrating them
- Keep isolation areas away from other livestock
- Ensure all fences and boundaries are strong to prevent interaction between farms
- Introduce a pest control programme to keep populations of vectors, such as ticks, down
- Vaccinate stock when necessary
Feed and water
- Fence off streams and rivers and make sure all animals have access to clean water
- Keep water bowls and drinkers elevated to reduce faecal contamination
- Keep pests out of feed storage and prevent access to wild animals and other animals, such as farm cats and dogs
- Make sure to keep feed in a clean, dry and secure area
- Only buy feed from reputable sources
- Avoid feeding swill, especially as it is illegal in many places
- Dispose of used bedding in a safe location away from livestock, watercourses and feed storage to prevent contamination
- Safely dispose of used equipment, especially veterinary equipment such as needles and syringes
- Remove any contaminated or dirty feed from stocks to prevent contamination
- Spread slurry on arable land, instead of grass for silage or pasture
- Keep livestock away from freshly spread slurry
- Dispose of fallen stock properly and hygienically
- Dispose of contaminated materials from illness or birthing, e.g. placental matter
There are many resources available which look at biosecurity in more detail. For UK farms, Defra have released extensive guidance on how to protect your animals and your farm. The AHDB also has useful information on practical steps you can take.
Many other governments have produced guidelines, specific to their countries. These can usually be found easily on their websites.