Introduction
If you are a rancher, farmer or anyone working with cattle, it’s important to understand the potential risks of Bovine Viral Diarrhea (BVD) and how it can affect your animals and your livelihood. BVD is a viral disease that can cause significant harm to your cattle and result in significant economic losses, especially if not prevented or controlled promptly.
What is Bovine Viral Diarrhea?
BVD is a highly contagious viral disease that affects cattle and dairy cows worldwide. The virus can manifest in two forms: BVDV1 and BVDV2, with the latter being more pathogenic. Symptoms of BVD involve respiratory and enteric conditions, and the disease can severely weaken the immune system of your cattle and make them more susceptible to other illnesses.
History and Background
BVD was first identified in the United States in 1946. Since then, it has been reported all over the world, with an estimated global prevalence rate of 90%. Because of its high prevalence rate, BVD has been recognized as a major challenge to the livestock industry.
Causes of BVD
The BVD virus is mainly transmitted through the fluids of infected cattle, such as saliva, nasal discharge, urine, and feces. The virus can also be spread indirectly through contaminated equipment and surfaces, such as feeders, water troughs, and even the air. The disease can also be passed from mother to calf during pregnancy.
Symptoms of BVD in Cattle and Dairy Cows
Some signs that your cattle may be suffering from BVD include the following:
- Fever
- Diarrhea
- Respiratory issues
- Ulcers in the mouth and nose
- Abortions in pregnant cows
- Weakness and lethargy
Testing, Prevention, and Control
Importance of Early Detection
BVD can be detected in your cattle through diagnostic tests, and if detected early, it is much easier and cheaper to prevent and control. Ignoring the symptoms of BVD may lead to a looming disaster in your herd since the disease can spread quickly, reducing productivity, and leading to lasting harm.
Diagnostic Tests for BVD
There are several diagnostic tests available to help identify BVD in your cattle. The most common tests include antigen detection, PCR testing, viral isolation, and serological testing. A veterinarian may use one or more of these tests depending on factors such as herd size, vaccination status, and potential exposure.
Methods for Preventing the Spread of BVD: Biosecurity Measures and Herd Management
The best way to protect your cattle from BVD is to prevent them from exposure in the first place. Practice biosecurity measures such as limiting access to your farm and training your workers properly. Also, manage your herd’s movements well, making sure that new cattle have been thoroughly screened and tested for BVD. Consistent use of management practices and biosecurity measures minimizes the risk of disease transfer through multiple herds.
Vaccinating Cattle Against BVD
Vaccination can be an essential tool in preventing BVD, especially in large herds. It is recommended to have your animals vaccinated under the guidance of a veterinarian. Actually, there are different types of BVD vaccines available depending on the needs of your herd. Talk to your veterinarian for the best vaccination options and schedule to use for your animals.
The Economic Impact of BVD on the Cattle Industry
Costs Associated with BVD
BVD can be expensive as treatment and control measures can lead to high costs on the part of the farmer. The cost of treatment of BVD and costs with additional labor hours due to clinical and sub-clinical infections and all the associated issues composes a significant expense. This can lead to increased expenses with lower productivity. Farmers may also need to buy vaccination doses, pay vaccination services, and put in place measures to minimize the spread of the disease.
Losses due to Disease Outbreaks
Another significant cost due to BVD outbreaks is the loss of animals, reduced milk production, abortion in pregnant cows due to BVD, and reduced weight in infected animals. These losses can be enormous, not only in monetary terms but also in animal health, productivity, and welfare.
Long-Term Effects on Herds and Farms
BVD can have long-lasting effects on your herd and farm, especially if the disease is not detected and treated early enough. The disease may cause a reduction in the production capacity of your cattle, increase morbidity, and mortality rates. If not diagnosed and treated in time, herds can continue being infected for years, and the circulation of the virus may lead to a difficult situation, with animal disease testing or carcass quarantine.
BVD in Dairy Cows: Effects on Milk Quality and Cow Health
How BVD Affects Milk Production
BVD can significantly reduce the milk yield and its quality in dairy cattle. The virus can decrease butterfat levels in your milk, reduce the protein content, alter the flavor and odor, and decrease the overall value of the dairy product, leading to a substantial economic loss. This decrease in milk quality and volume can have a significant impact on the dairy industry and a lasting effect on the milk production capacity of the herd.
Impact of BVD on Dairy Cow Health
BVD can also cause significant harm to dairy cows. The virus can suppress the immune system, making the cow more vulnerable to secondary infections. Additionally, infection can lead to prolonged respiratory symptoms, reduced weight gain, and in some cases, death. BVD can also impact breeding performance, leading to abortion, stillbirths, and other reproductive issues.
Risks and Benefits of Vaccination for Dairy Cows
Vaccination can minimize the risk of BVD in your dairy herd. However, best practice is to have your animals vaccinated under the guidance of a veterinarian. Talk to your veterinarian about the best vaccination program to coordinate with your breeding program since some vaccines might cause a failure of pregnancy or reduced fertilization capacity in the affected cattle.
How BVD Spreads and What Ranchers Can Do to Control It
Transmission of BVD: Direct and Indirect Routes
BVD can be transmitted through direct or indirect routes. The direct transmission occurs when cattle come into contact with infected cattle, while indirect transmission happens when cattle come into contact with fomites, which are inanimate objects contaminated with the virus. Methods to minimize contact between animals are vital in the prevention and control of BVD.
Strategies for Controlling BVD: Isolation, Testing, and Removal of Infected Animals
Controlling BVD involves several measures, including prompt testing and isolating infected cattle from uninfected ones. Infected cattle should be removed from the herd and placed into a quarantine area. After clearance from quarantine, the animals should undergo follow-up testing to prevent any re-emergence of the disease in the herd.
Environmental Factors that can Contribute to the Spread of BVD
The environment can play a significant role in virus transmission. Biosecurity strategies should help minimize the spread of BVD, and reduce the risks associated with the disease. Also, train your workers to clean and disinfect animal housing, feeding areas, water troughs, and all shared equipment thoroughly.
Diagnosing Bovine Viral Diarrhea: Getting Accurate Results and Responding Appropriately
Importance of Accurate Diagnosis
Early detection and accurate diagnosis are crucial to the management and control of the disease. The virus can have various symptoms or sometimes none, highlighting the need for a definitive diagnosis in all cases of clinical signs. Science-based laboratory testing is essential to provide recommendations for BVD control, eradication, and prevention.
Different Diagnostic Tests for BVD
The diagnostic tests for BVD are based on the determination of the presence of viral antigens, RNA, or antibodies in blood samples. PCR testing, serological assays, tissue biopsy, and antigen capture ELISA are some of the diagnostic methods used to identify and confirm BVDV infection.
What to do if BVD is Confirmed in a Herd: Culling, Treatment, and Prevention
Once BVD is confirmed in a herd, it’s essential to work closely with your veterinarian to devise a management strategy that is culturally acceptable and includes vaccination strategies if needed. Infected cattle may need to be culled to prevent the disease from spreading within the herd. Vaccinations would need to be implemented, measures to minimize contact among infected and uninfected animals to prevent disease transmission. Coordinate with disease control agencies, and other stakeholders to help manage BVD and promote a healthy herd.
Conclusion
BVD is a common and costly disease that can significantly affect your cattle’s health and productivity. Early detection, vaccination programs, and management strategies, including proper disposal of waste materials and animal equipment, are essential in controlling the disease. Partner with your veterinarian to design a prevention scheme that is effective and practical for your herd.