Stop! Biosecurity Measures are in Effect! Preventing the introduction of disease in a calf rearing facility

By Dr. Cynthia Miltenburg on behalf of the Bovine Ontario Animal Health Network

After an outbreak of disease, producers are often left wondering – where did it come from? For many farms, particularly calf-raising operations, there are multiple avenues for introduction, and we might never know beyond speculation exactly how a new disease was introduced. However, a review of the avenues into a farm can help producers consider what gaps might exist and how we can close them. In this article, we will consider the possible routes of introduction and what biosecurity barriers can help reduce the risk.

Introduction of diseased cattle or healthy cattle that are incubating a disease

For calf raisers that are receiving cattle from multiple sources, the risk of introduction will always be high, particularly for cattle that are sourced through auction. Where direct buying relationships exist, regular communication with the source herds on their health status and colostrum and vaccine protocols can reduce the risk. For all cattle, but especially cattle sourced from auction, maintaining small, static groups can reduce spread should a new pathogen be introduced. Handling healthy animals before sick, and young before old can help protect the most susceptible animals.

On people via clothing and boots

Visitors to our farms includes everyone from neighbours to service providers, and farm tour participants to international visitors. No visitor should wear clothing or footwear that has been on another farm without first being cleaned and disinfected. Ask if clothing has been laundered in hot water and dried on hot, for example, or provide clean coveralls you will wash. Providing disposable boot covers are a simple way to cover shoes or footwear that isn’t easily cleaned or changed. Don’t assume any visitor will automatically follow good biosecurity protocols and be prepared to enforce your own farm protocols.

Farm equipment and vehicles

Any vehicles that go between farms have the potential to carry and spread disease. Wherever possible, do not bring unnecessary vehicles close to the farm buildings. Instead have visitors park away from the livestock facility to limit cross-contamination between your farm and previous locations visitors have attended. Livestock for transport and deadstock for pick-up should be loaded away from the building to prevent external vehicles from accessing the zone around the facility traversed by the farm’s own vehicles and equipment.

Other animals on the farm including other livestock species, pets, wildlife, rodents, and insects

Farm dogs and cats are common on operations and may play an important role in rodent control and security. To protect cattle, restrict cat and dog access to livestock and feed storage areas to avoid urination or defecation in cattle feed or water sources. All cats and dogs should be up to date on vaccines and parasite control. Not only does this keep them healthy but reduces the risk of spreading diseases such as leptospirosis, rabies, toxoplasmosis, or tapeworms to livestock. Pets that are spayed or neutered are less likely to roam and visit other properties or attract other cats or dogs to the farm.

If other food production species are present on the farm, maintaining separate facilities and using dedicated clothing, boots, and equipment for each group will limit the risk for introduction of disease to cattle.

Keeping buildings secure and repaired will limit opportunities for wildlife to access the buildings. Livestock feed is the biggest attractant so keeping feed areas secure and cleaned up daily will reduce interest from raccoons and other animals. Wild birds are often attracted to livestock barns and can contaminate feed and water through droppings and spread diseases such as Salmonella. Observing how birds are entering and taking steps to minimize bird entry are key. A pest control company may be needed to assist with persistent wildlife issues.

Rodents can spread some serious diseases including Salmonella Dublin. Evidence of rodents such as droppings or nests should prompt action to address these pests. Flies and other insects can spread bacterial and viral diseases and be a nuisance to cattle. A multimodal approach to control includes sanitation and manure management, mechanical control such as tape or traps, and chemical control.

Contaminated feed, water, or bedding

If purchasing feed or bedding substrate, know the supplier and report back if any quality issues are observed. Reuse of any material that has already been in contact with livestock elsewhere is high-risk. Water sources on-farm should be secured to prevent contamination from manure or chemicals.


Some pathogens can be shed into the air through the respiratory tracts of animals or animal feces and remain in the air as particles or attach to dust. For most pathogens, such as IBR (Infectious bovine rhinotracheitis caused by bovine herpesvirus), the particles are carried short distances and only animals in adjacent pens are at risk of infection via this route. Vaccine programs can help prevent transmission to other animals on the farm. Longer distance airborne transmission is rare for cattle diseases but does occur in other commodities such as Malignant Catarrhal Fever spread to bison on nearby farms or Coxiella in small ruminants. Although both diseases can also affect cattle, they are usually less severe in cattle. Knowing the livestock farms in close proximity to your own can help understand this risk.

Simply put, biosecurity is using management practices to prevent the introduction and spread of infectious disease. We often only consider the costs such as the inconvenience of the protocol or the purchase of materials such as boot covers, however protecting our farms from introducing disease helps protect overall productivity and farm income. It’s challenging when well-done biosecurity results in nothing exciting happening – but that nothing is saving you money! While some risk will always exist, attention to avenues for introduction can help manage the gaps and biggest vulnerabilities.

The Bovine Ontario Animal Health Network is a group of veterinarians and specialists working in government, university research and laboratory, and in beef, dairy, and veal practice who meet regularly to monitor and discuss disease trends in Ontario. Our goals are to facilitate coordinated preparedness, early detection, and response to animal health and welfare in Ontario. For our recent reports or more information visit