Biosecurity in sheep farming encompasses various management practices designed to protect the flock from infectious diseases, pests, and other health risks. The aim is to prevent the introduction and transmission of disease-causing agents to animals by direct or indirect means. Diseases can spread quickly within a flock, leading to illness, reduced productivity, significant financial losses, and even death in extreme cases.
Biosecurity should not be confined to large operations; it is vital for all flock sizes. It takes just one sheep to introduce a new disease, and a single farm can trigger a disease outbreak. Hence, biosecurity practices should be a critical component of every operation's health management plan.
Biosecurity is not just about protecting farm animals; it also involves safeguarding the shepherd and farm workers. Some diseases can be transmitted from sheep to humans (zoonotic diseases), making the implementation of biosecurity measures essential for ensuring the safety of animals, farm workers, visitors, and the wider community.
Healthy animals are fundamental to a successful sheep operation, which is why it is crucial for sheep managers to prioritize biosecurity measures. Here are some general guidelines for implementing on-farm biosecurity.
Isolation and quarantine
All new animals arriving on your farm should be isolated for at least 30 days before being mixed with other animals or allowed to share pasture with your existing flock. New introductions should also not have fence line contact with the existing flock at this time. Isolation allows you to monitor the health of the new sheep for signs of illness or disease. Many diseases may not show symptoms immediately, so a period of observation helps identify any potential health issues. The isolation period is an ideal time to implement health protocols such as vaccinations or hoof care and perform infectious disease testing to ensure that new animals are in good condition before joining the flock. Newly purchased sheep may have different parasites and/or parasite burdens compared to your existing flock. Isolation provides an opportunity to deworm the animals and monitor for any signs of parasites before introducing them to the main flock. Producers should gather the deworming history from the farm they purchased the new sheep, including which dewormers they have used and the frequency of their deworming practices. If they are dewormed during this time, a fecal egg count should be conducted 10 to 14 days after treatment to determine whether the deworming was effective. Keep your entire flock up to date on vaccinations as recommended by a veterinarian.
Animals purchased at sale barns often come with unknown health histories, including vaccination status, previous exposure to diseases, and overall health conditions. This uncertainty may lead to the introduction of health issues into your flock. If you plan to incorporate animals from a sale barn, it is essential to quarantine them before adding them to your existing flock. Keep the new sheep isolated for at least 60 days to monitor their health and check for signs of illness. This reduces the risk of disease transmission on your farm. An animal that appears healthy may still be harboring a disease or other issues that could hinder its productivity. Quarantined animals should be cared for during the isolation period and not be neglected.
Implementation access restrictions
I recently participated in a bus tour to a sheep farm with about 20 other producers. We remained on the bus and were not permitted to step onto the pasture. This served as an excellent example of limiting farm access to essential visitors only. Limiting access helps reduce the risk of introducing infectious diseases and pathogens that can be brought in by visitors, vehicles, or equipment. On another occasion, I was provided with footwear before entering the sheep farm to minimize the risk of introducing contaminants or pathogens into the environment. This practice helps maintain biosecurity by ensuring that no dirt, manure, or other potential sources of infection from outside the farm are brought in, protecting the health of the sheep and the overall farm operation. It is also a good practice to maintain a record of visitors, as well as any trailers or trucks that come to your farm. Disinfect footwear by using a footbath filled with a potent sanitizing solution. Scrubbing with soap and water is an important step for farms to be aware of before using a disinfectant, as sanitizing sprays are likely to be inactivated by organic material.
Maintain good hygiene practices
Good hygiene practices are essential for sheep biosecurity, as they help prevent the introduction and spread of diseases on the farm while contributing to overall flock health. Regular cleaning and sanitization of equipment, barns, and feeding areas minimize contamination and control parasites, ultimately ensuring that sheep have access to clean food and water. Furthermore, these practices protect both animals and farm workers from zoonotic diseases, enhance biosecurity measures, and help farmers comply with health and safety regulations, leading to healthier animals and improved productivity. Producers should establish and maintain a veterinarian-client-patient-relationship (VCPR). As the saying goes, "prevention is better and cheaper than cure." These management practices emphasize that it is easier to prevent diseases than to treat or respond to issues that arise from them. For more information on this subject, please visit the American Association of Small Ruminant Practitioners Biosecurity Tool Kit Resources. To develop a custom biosecurity plan tailored to your specific farm, the Center for Food Security and Public Health (CFSPH) provides resources and guidelines designed to enhance farm protection against diseases. You can also work with your veterinarian to develop a plan tailored to your farm or specific diseases of concern.
References
- Susan Schoenian. University of Maryland Cooperative Extension - Biosecurity on sheep farms.
- USDA - Animal and Plant Health Inspection Service (APHIS). Biosecurity for sheep and goat producers.