Farms use biosecurity to:
• Prevent infectious disease organisms from entering the farm.
• Control disease spread within and between barns and farms.

Studying flows on your farm is an orderly way to plan how the following move into, through, and from the facility.
• People
• Birds
• Feed
• Supplies
• Materials
• Equipment
• Ventilating air
You can also study flows to assess and maintain your biosecurity, and efficiently and safely carry out the operation’s management and operational plans.

Step 1
Define and draw system boundaries and line(s) of separation
A system boundary can define either a farmstead or an individual barn. Lines of separation define clean areas from dirty areas. On most farm sites, you must consider farmstead and individual barn boundaries and lines of separation.

You can define a system boundary around the farmstead
• Roads
• Property lines
• Gates and fences

You can define the barn’s boundary by
• Roof
• Sidewalls
• Doors
• Air inlets
• Air outlets
• Exhaust fans

Barn entrances play a key role in barn boundaries because this is where people and supplies cross a line of separation into clean biosecure areas. You can define lines of separation by painting a line or curb on the floor. You can use multiple barns connected by enclosed hallways to define the boundary between inside and outside.

Step 2
Identify every flow that crosses the boundary or line or separation
General farmstead flows can include
• Employees entering and leaving the farmstead
• Non-employees such as service providers, veterinarians, package couriers, sales consultants, and visitors entering and leaving on occasion
• Feed and feed trucks
• Live birds moving in and moving out – trucks, equipment and employees
• Mortalities leaving barns and the farmstead
• Eggs leaving a layer operation
• Bedding supply trucks
• Supplies and delivery trucks (mail, packages, other)
• Garbage truck and physical trash
• Manure handling equipment
• Manure leaving
• Fuel trucks
• Employee work clothes and boots
• Food and drink for employees

Barn flows can include
• Airflow in and out
• Feed flow in
• Live animals in and out
• Mortalities out
• Animal care givers with dirty hands and cloths in and out
• Service people, consultants, and visitors with dirty hands, equipment and clothes
• Equipment in and out — machinery, tools, etc.
• Personal items including glasses, jewelry, and phone
• Supplies in — inventory, ordering, delivery, storage, cleanliness

• Bedding added
• Used litter and manure removed
• Water in
• Trash, including used plastic boots, gloves, disposable coveralls, and other things
• Clean boots and coveralls in and dirty boots and coveralls out
• Used boot dip or dry disinfectant
• Cleaning supplies in, used dirty supplies leaving, and empty containers out
• Toilet wastes and wash water out
• Rodents, flies, and wild birds
• Others

Step 3
Describe or track each flow
• Where do the inflows come from, and where have they been?
• Where do the outflows go?
• Are there branch flows (ex. people leaving trucks that enter a farm or barn)?
• Can the material or person become contaminated?
• How much flow occurs? When?
• How is the flow or transport done?
• What happens along the way as the flow passes through the barn or farmstead?

Step 4
Assess the biosecurity risk for each flow and rank the risks you need to manage more carefully
Assume that the flows are dirty, whether incoming or outgoing.
• What risks are there with each flow (ex. feed, water, air, bedding, people, trucks, wild birds, flies, rodents, other)?
• Can the flow cause disease spread? If yes, how can you reduce this risk?
• What treatments or practices can you use to reduce the risk of disease spread?
• What are the costs and risks?
• How much does a practice cost to carry out in equipment, operating costs, time, and labor?
• Is the practice practical? Does it fit within the farm’s management plan?
• What are the benefits of the practice? How does it reduce the risk of disease spread?

Step 5
Develop and carry out plans to better manage the biosecurity risk of each flow
• Minimize the introduction of disease by developing clear instruct ions and providing facilities, equipment, supplies, and trained personnel for managing each flow.
• Minimize the spread of disease through materials by developing clear instructions and providing facilities, equipment, supplies, and trained personnel for managing each process.

Always make flow management and biosecurity practices easy. People are likely to do a job well if it’s easy to do with the right equipment.

Quick facts
• Define system boundaries around barns and farmsteads and line(s) of separations to separate clean from dirty areas.
• Be aware of every flow that crosses system boundaries and lines of separation.
• Track each f low, such as people, equipment, and supplies.
• Know the risk for each flow and decide which risks you need to manage more carefully first.
• Create and carry out biosecurity plans to reduce the risks for each flow.