A farm biosecurity line of separation is established to act as a barrier that reduces the spread of diseases. The biosecurity line separates the "clean" from the "dirty", and is part of the zones that you create to either increase or lower restrictions of movement, sanitation, vehicles, visitors, manure management, deadstock handling, etc. depending on how close they are to livestock areas.
Where to Locate a Line of Separation
On the Traffic Control page, establishing zones on your farm is a first step in designating where the flow of visitors, vehicles, deliveries, etc. should be directed. The zones are:
- Restricted access - high risk areas near livestock.
- Transition zone - medium risk areas where the line of separation is located.
- Controlled access - medium to low risk areas.
The line of separation (the transition zone) is established to isolate livestock living areas (restricted access) from potential sources of disease. The line should clearly indicate who is allowed to cross and it and what they must do before crossing the line.

Example of a Danish Entry Set Up for Crossing the Line of Separation. Outside entry is from the left side.
The images below show various examples of Line of Separation areas on farms, and what the entrances look like. Whatever the size of an operation, stations for cleaning and disinfecting before and after working directly with livestock is a good biosecurity practice.

Source: Center for Food Security and Public Health. 2019 Information Manual for Implementing Poultry Biosecurity.
On-Farm Danish Entry System Video
In addition to providing a barrier to human entry, a line of separation (LOS) can be used to exclude wildlife and other animals from crossing and contacting livestock. Barriers should be intact and maintained to keep wild birds, rodents, deer, feral swine, etc. out of livestock areas.
Establish LOS Entry Procedures
Each building or group of connected buildings where livestock live should have a single-entry crossing to the animal side of the LOS, to create a biosecure entry and exit procedure for personnel and equipment when crossing. The LOS should be clearly marked (such as with tape or paint, walls and doors, etc.) and have appropriate signage in language(s) understood by all entering.
The following are minimum essential components that should be provided at the LOS access point:
- A visually defined line of separation.
- An area for personnel to change out of their footwear and outer clothing prior to crossing the LOS, and an area for putting on site-specific footwear and outer clothing after crossing the LOS.
A farm may have as many lines of separation as there are buildings for housing livestock, feed, and other items animals will come in direct contact with. A group of buildings connected by enclosed walkways may all be within the same LOS. These items are needed to follow a basic entry procedures for crossing the LOS (e.g., site-specific coveralls, footwear):
- Supplies to clean and disinfect equipment.
- A sink with running water and soap or hand sanitizer and signage instructing personnel to clean their hands.
Entry Log Book
Keep track of who is visiting your farm by setting up an entry log book. The farm owner or designated biosecurity coordinator is the best person to maintain the log book. The log book should be located in the controlled access/perimeter area of the farm. Anyone who is allowed to enter is asked to sign the log book and include the following information:
- Name
- Company affiliation
- Date
- Phone number
- Reason for entry
- Date and description of recent visits to other farms
Download the biosecurity plan template here for the log in forms.
Entry and Exit Procedures for Visitors
- Leave personal items such as cell phones and jewelry outside the LOS, unless these personal items are permitted and allowed to undergo cleaning and disinfection procedures.
- Remove street shoes/boots, socks.
- Remove outer layer of clothing (e.g., a coat) to allow changing into site-specific clothing (coveralls or similar).
- Ensure hands are clean.
- Wash hands and/or sanitize hands.
While crossing the LOS:
- Take care to not contaminate clothing, footwear, exposed skin, or other items from one side of the LOS to the other.
After crossing the LOS, before contacting livestock:
- Ensure hands are clean.
- Wash hands and/or sanitize hands.
- If disposable or disinfected gloves are used, they should be put on over clean hands.
- Put on clean biosecurity PPE (i.e., site-specific coveralls or clothing).
- Ensure that any street clothes or accessories, if permitted, are completely covered by biosecurity PPE.
- Put on clean, site-specific boots or boot covers.
- Or, put on disposable boot covers.
- Or, clean and disinfect boots using proper cleaning and disinfection steps, including appropriate disinfectant contact time.
In most cases, the entry procedure is followed in reverse when crossing the LOS to exit the building. The goal is to remove visible contamination on personal protective equipment (PPE, boots or boot covers, coveralls, gloves, hair nets) and exposed skin before leaving the site, in order to prevent transmission of infectious agents to other locations with susceptible livestock.
Visitors should remove any farm-dedicated protective outerwear and disposable PPE, clean and disinfect farm-dedicated footwear, and wash hands before crossing the LOS. Soiled clothes and footwear could be left on the site to be laundered or cleaned.
If the site does not provide running water and soap, and a scrub brush, water and disinfectant, non-farm personnel should have a portable way of disinfecting anything they bring with them onto the farm. If soiled clothing or footwear must be removed from the site, it should be placed in a closed bag or container and stored until it can be laundered or cleaned and disinfected. Some sites may also have more stringent biosecurity measures, including showering out upon leaving the building and/or site.
Biosecurity for Transporting Livestock and Poultry Videos
The videos below were created by the North Dakota State University Livestock Extension.