Dairy Cow Biosecurity Overview
There is a real risk of disease in your dairy cattle herd. As a dairy cattle producer you are aware of many of the common diseases that could potentially affect your animals. You have probably also noticed that diseases which exist in some groups of animals in your farm do not exist in other groups. For instance, calves can have a disease not present in cows, and animals in one barn may have a disease not present in another.
Biosecurity is an essential part of maintaining your herd's health as well as the profitability of your operation, an overall plan for your farm is essential. Even if you practice some biosecurity measures now, a plan is needed to make your farm as safe from disease as possible. This plan will allow you to determine the measures needed to set up a comprehensive program to protect your herd in the best way possible.
Implementation of sound biosecurity procedures will reduce the chance of the spread of a disease among the different groups of animals within the farm, and it will also reduce the chance of a disease being brought to your farm.
A biosecurity plan must include a standard health protocol. This protocol documents standard operating procedures for maintaining herd/flock health, routine husbandry and health procedures, and specific methods to identify, separate, and treat sick animals.
Below is a list of biosecurity measures that are categorized under general topics. These are best management practices, and this list can be used to develop your own biosecurity plan.
Management Strategies
- Establish and implement an efficient and effective herd health plan with input from your veterinarian.
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- Include written Standard Operating Procedures (SOP) for health procedures.
- Include written SOP for treating sick animals.
- Observe all animals at least once daily for signs of disease, including lameness, loss of appetite, salivation, lethargy, or sudden death.
- Individual animals or the entire herd should be examined carefully by a veterinarian if signs of disease are noted.
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- It is especially important that a postmortem examination be performed if unexplained livestock deaths occur.
- Biological specimens should be submitted to a diagnostic laboratory if the cause of disease problems is not obvious.
- Special attention should be paid to equipment such as livestock trucks and trailers, manure loaders and spreaders, tractors, portable livestock chutes, and other fomites that could easily spread disease from one site to another. Clean equipment thoroughly after each load.
- Locate delivery/loadout facilities at perimeter of property.
- Livestock exhibitions, other than terminal shows, should be avoided if possible.
General Recommendations
- Maintain a closed herd if possible (i.e. do not bring in new additions to herd).
- Maintain excellent records for all animals and keep the records up to date. Include the following information:
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- Individual identification
- Origin (natural addition or purchased)
- Vaccinations
- Test history
- Clinical signs, treatments, cause of death or cull, etc.
- Identify animals individually in accordance with the traceability standards.
- Separate the herd into similar groups, such as calves, heifers, lactating cows and dry cows.
- For pastured animals, disperse hay feeding areas to prevent congregation in one area.
- Have a valid veterinary/client/patient relationship and include your veterinarian in herd health decisions.
- Create Standard Operating Procedures (SOP) on what to do for different diseases/conditions.
- With help from your veterinarian, develop a vaccination protocol to improve herd level immunity.
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- Consider vaccinations for: respiratory agents [Infectious Bovine Rhinotracheitis (IBR), Bovine Respiratory Syncytial Virus (BRSV), Parainfluenza Virus type 3 (PB), Bovine Virus Diarrhea (BVD type 1 & 2)], clostridium and leptospirosis.
- Administer booster vaccination when recommended and allow four weeks for immunity to develop for most vaccines. Understand vaccination may only reduce clinical signs in animals and not prevent infection.
Resident Animals
- Construct all stalls or pens to avoid physical contact or shared air among cows of different ages.
- In facilities with multiple stalls or pens and cows of different ages, sequence the care of animals so that those with the highest health status (usually younger cows) are cared for first. Daily chores should be completed in the order of highest health status to lowest health status. Calves should be taken care of before attending to the milking herd to help prevent spreading the pathogen load from the older animals to the younger cows.
Calves
- Diarrhea is the most common cause of death of neonatal calves.
- Keep the calving area sanitary and use a regular cleaning and disinfecting SOP.
- Remove the calf from the calving pen as soon as possible and dip the navel with appropriate product.
- Maintain good colostrum management: complete records, one cow to one calf, give the best colostrum to replacement animals, one gallon of good quality colostrum as soon as possible after birth, etc.
- Keep calves on an excellent plane of nutrition.
- If feeding waste milk, pasteurize and monitor for pasteurization failure.
- House calves individually to prevent nose-to- nose contact with other calves.
- Consider the use of inorganic bedding (sand and gravel).
- Schedule to vaccinate calves prior to placing in group pens.
Heifers
- Remember that respiratory illness is the most common cause of death of heifers. Coccidiosis is also a common disease.
- If possible, house heifers in smaller groups (such as 6-10 animals) then move to larger groups (such as 20-30 animals) as they grow larger.
- Keep heifers in a body condition score (BCS) of approximately 3/5.
- Do not feed heifers leftover feed from older animals.
- Try to group heifers in similar age groups.
- Separate out poor doers and place in a recovery pen.
Lactating Cows
- Use artificial insemination (AI) to reduce disease transfer, ensure human safety, and improve economics.
- Establish a designated pen where animals being treated or are sick may be kept under a close observation.
- Comply with all meat and milk withholding periods.
- Have a logical milking order: milk healthy animals first and sick and treated animals last.
- Cull chronically diseased animals, those infected with Johne’s disease, S. aureus, Mycoplasma, etc.
- Monitor bulk tank somatic cell counts (SCC) and bacterial counts.
- Perform bacterial culture and sensitivity testing on mastitis cases to improve antibiotic treatment.
- Identify animals that abort and submit the fetus and placenta for your veterinarian to examine.
Dry Cows
- Supply dry cows with a comfortable environment and good nutrition.
- Use dry-off treatments and coliform mastitis vaccinations during the dry period.
Bulls
- Use artificial insemination when possible.
- Routinely perform breeding soundness exams on bulls, ideally every 4-6 months.
New Animals
- Maintain a closed herd and grow herd size internally or minimize frequency and number of new additions to your herd.
- Designate isolation or quarantine facilities for all new animals (refer to Facilities section).
- Isolate new animals or returning animals for a minimum of three weeks before introducing them into the resident herd.
- Limit purchases to a single source with known and trusted herd health programs:
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- Ask the seller to test the animals to be purchased 1-2 times within 30 days of shipping.
- Ask for a written account of the seller’s herd health information and review this with your veterinarian before animals arrive on farm, such as complete vaccination history, mastitis status, Johne’s disease status, BVD status, Tuberculosis (TB) test negative, etc.
- Purchasing animals from sale yards or auction markets presents a higher risk of bringing disease onto your farm since complete histories of animals may not exist.
- Observe new animals for clinical signs while in isolation in your quarantine facility. Test new animals for BVD, Johne’s disease, mastitis (Mycoplasma, S. aureus, etc.), Salmonella, etc. (remember that a negative test may not guarantee freedom from disease).
- Vaccinate new animals prior to transportation. Realize that vaccinating animals when stressed (recently transported, new environment, recently weaned, etc) may not be the most effective vaccination strategy.
Employees
- Check references and perform background checks for all prospective employees.
- Provide supervision to all new employees.
- Restrict employee access to their respective work areas.
- Train employees in good animal handling techniques. Good stockmanship adds to a positive environment that assists in maintaining animals immunity against disease.
- Train all employees to recognize signs of disease, alert supervisor of suspicious activities, and understand and follow procedures within the biosecurity plan.
- Train employees to understand that the movement of manure (on clothing, boots, equipment, animals, etc.) is one of the biggest biosecurity risks for on farm movement of diseases.
- Warn employees who have contact with off farm animals of the same species to not track off farm manure onto your farm.
- Require employees to wear clean clothing and boots.
- Create protocols for cleaning clothes daily and for washing boots and hands regularly.
- Require employees to wear gloves when milking, caring for sick animals, assisting with births, and collecting dead animals.
- Require employees to work through groups of animals in a certain order, from clean to dirty, young to old, and healthy to sick, to reduce spreading disease to the more susceptible animals.
- Require employees working in “high risk areas” to remain in those areas or change clothing and footwear before working with the other animals.
- Retrain employees regularly to maintain a high level of employee performance in all their tasks including the biosecurity plan.
- If desired, perform a baseline laboratory screen for all new employees to detect exposure to, or infection with, certain diseases that are present in both human and animal populations (e.g., tuberculosis).
Visitors
- Visitors include routinely scheduled persons (veterinarians, haulers, fuel/feed deliveries, inseminators, vaccinators, utility readers, etc.) and non-routine persons (tours, salespeople, other livestock owners, and regulatory personnel) who visit your farm.
- No person should enter your farm without your prior approval.
- All visitors should sign a log book. Include information such as date, name, organization, phone number, reason for visit, and the last time they had contact with livestock. This list will be an important tool used by investigators to contain an outbreak.
- Evaluate the level of risk associated with your visitors: Do they own animals? Do they move between farms? Will they have close contact with your animals? Have they recently returned from another country?
- Do not allow anyone who has been on a farm in a foreign country to enter livestock units for a minimum of five days after returning to the US. Other countries may have diseases in their herds that are considered Transboundary Animal Diseases to us.
- Restrict visitors to the specific areas on the farm required for their task(s). Post signs to inform visitors of rules to follow while on the farm.
- Do not allow visitors to bring food articles with them on the farm as these items may contain harmful bacteria or other disease-causing agents.
- Visitors should be provided with new plastic shoe covers, clean rubber boots, or they should brush and then disinfect their shoes/boots with appropriate disinfectant before and after visiting the operation (disinfectant will not work unless surfaces are clean and an adequate contact time is allowed.).
- Visitors who will have contact with animals should wear clean coveralls.
- Visitors should wash hands their hands thoroughly with soap and warm water or hand sanitizer before and after entering animal areas.
- Limit access to your farm through gated entry sites that are clearly posted with signs.
- Post signs advising visitors that this is a biosecure area, and who to contact for entry permission.
- Lock gates and buildings when not in use.
- Repair and maintain fences. Fences should keep pastured animals away from roads and other farms; and should keep predators away from your animals.
- Park vehicles away from dairy facilities, animal feed storage areas, and manure handling routes. Park all vehicles in designated areas, preferably on hard surfaces such as concrete or asphalt. Dirt, mud or manure on vehicles must not be allowed on unpaved areas. Use signs and/or barriers to direct vehicles to the designated areas.
- Do not allow outside vehicles to drive across cow lanes or lanes used for feed and manure handling equipment.
- Do not share vehicles, trailers or equipment with other farms, without cleaning and disinfecting between uses.
- Be prepared to disinfect vehicle tires and wheel wells during a disease outbreak if a vehicle has to drive into flock production areas of your property.
- Buy feed from known, reliable vendors, and record all transactions.
- Protect feed from weather and moisture to prevent spoilage and mold growth. Remove and destroy spoiled feed and dispose of refused feed.
- Keep manure handling and feed handling equipment separate.
- Protect feed from vehicle and foot traffic, as well as from manure or urine run-off.
- Clean up and dispose of feed spills around storage bins and feed tanks to avoid attracting wild birds or rodents.
- Completely clean out all feed storage areas between shipments.
- Observe FDA guidelines about the feeding of animal byproducts to ruminants.
- Feed and equipment delivery points preferably should be located near the perimeter of the farm.
- Provide clean, fresh water source. Do not allow cows to drink from ponds or run-off sources.
- Prevent contamination of water sources from manure or dead animals.
- Prevent animals from standing in the source of drinking water.
- Clean and inspect the water delivery system regularly.
- Test well water for chemicals, mineral levels, heavy metals and microorganisms periodically.
- Be aware of current Confined Animal Facility Operation (CAFO) laws and regulations.
- Locate manure storage areas away from animal areas and prevent run-off into feed or water sources.
- Remove waste, as needed, and transport it with designated equipment to a designated storage or disposal area.
- Avoid spreading manure where susceptible animals graze, or, allow adequate time (specific to the situation) between spreading and returning animals to pasture.
- Develop a written pest control program, including a regular service schedule.
- Follow directions on baiting chemicals and place where resident animals and farm pets do not have access.
- Rodents (mice, rats) – do not allow excess feed to build up and eliminate enclosed pathways for rodents to enter the building. Eliminate piles of wood and debris that could serve as rodent hiding places.
- Insects (flies, darkling beetles, mosquitoes) – focus control measures on manure, waste feed, ponds and other areas which are their breeding grounds.
- Wildlife (wild birds, raccoons, opossums, skunks, deer, feral swine) – restrict contact with wild animals using proper fencing, pens or enclosed housing.
- Hunters should keep dead game away from resident animals.
- Keep pets out of animal production sites, as they can spread disease too!
- Immediately dispose of all dead animals in an approved manner such as burial, incineration, composting, or landfill.
- Submit your animal for postmortem examination or have your veterinarian do this exam on the farm to determine cause of death.
- Provide a secure pick-up site away from public observation where dead stock vehicles do not have to enter or come near animal units.
- Dispose of dead animals using an approved method or site if a commercial confined facility, as specified in the producer’s permitted Comprehensive Nutrient Management Plan or Animal Facilities Management Plan. This management plan must provide both a normal and a catastrophic mortality disposal / treatment method. A catastrophic plan must be in place for a disease or natural event in which the mortality rate is higher than normal or more than the normal mortality plan options can handle.
Exhibitions should be avoided if possible, or follow the steps below to reduce bringing diseases back to your farm.
Before the Event
- Examine the animals before leaving for the event to make sure they are healthy.
- Clean and disinfect all equipment before it is taken to the event and prior to being returned after the event.
At the Event
- Limit contact between humans and animals and between the different groups of animals.
- Cover feed and equipment to reduce contamination.
- Do not share equipment unless cleaned and disinfected between users.
After the Event
- Change all clothing before returning home.
- Discard any leftover feed and bedding.
- Clean and disinfect equipment before loading for home.
- Isolate and monitor the animals after returning home (using traffic pattern rules and clothing changes you use for regular isolation areas).
Dairy Biosecurity Content Source
Choueke, Esmond. 2015. Agroterrorism Prevention Reference Guide (FBI). Boca Publications Group Inc. bocagroup@gmail.comDairy Cow Biosecurity Resources

Dairy Biosecurity Practices
A printable quick reference on dairy cow biosecurity, from Texas AgriLife Extension.

Organic Livestock Production
A USDA guide for the organic production and certification processes.

DAIReXNET
A national website for producers, allied industry, Extension and consumers, with articles, FAQs, Ask the Expert.

Secure Milk Supply Plan
Planning and developing a plan for continuity of business if foot and mouth disease occurs in the U.S.

Bovine Diseases
A comprehensive list of bovine (beef and dairy cow) diseases, from the Center for Food Security and Public Health.

Six Tricks of Biosecurity
A video for 4-H with tips to keep animals healthy at exhibitions, from the Upper Midwest Ag. Safety & Health Center.