The Effects of Bovine Viral Diarrhea Virus (BVDV) and Persistently Infected (BVD-PI) Calves on Cow/Calf Operations.

 Article and photos courtesy of Central State Testing.

BVDV is a significant concern for cow/calf producers worldwide. The presence of PI cattle amplifies the impact of BVDV on these operations. This article aims to explore the effects of BVDV and PI calves on cow/calf operations, including economic losses, decreased reproductive performance, compromised immune function and increased susceptibility to other diseases. By understanding these effects, producers can implement effective management strategies to control BVDV and mitigate its consequences, ensuring the long-term profitability and sustainability of their operations.

BVDV and PI cattle inflict substantial economic losses on cow/calf operations. Infected animals experience reduced weight gain, decreased feed efficiency and impaired reproductive performance. Furthermore, BVDV-related health issues, such as respiratory and gastrointestinal problems, require veterinary intervention and additional treatment expenses.
The introduction of PI cattle into a herd exacerbates the financial burden. PI calves are persistently infected with BVDV, serving as a continuous source of virus shedding. Their presence poses a significant risk of infecting susceptible animals, prolonging the duration and severity of the disease within the herd. The ongoing transmission of BVDV can impede the overall performance and productivity of the operation, resulting in lost opportunities for increased revenue.

BVDV can also lead to temporary infertility in cows. Infected animals may experience extended postpartum intervals and delayed return to estrus, resulting in reduced pregnancy rates and longer calving intervals. This delay in reproductive success affects the overall efficiency and profitability of the operation.

BVDV compromises the immune function of infected animals, making them more susceptible to other diseases. The virus suppresses the immune system, leaving the animal vulnerable to opportunistic infections and increasing the severity of clinical signs. Concurrent infections can lead to increased morbidity and mortality rates, further impacting the profitability of cow/calf operations.

PI calves play a crucial role in perpetuating BVDV within the herd. Their constant virus shedding introduces a continuous source of infection, increasing the viral load and maintaining a reservoir of BVDV within the operation. This environment of persistent exposure compromises the immune function of susceptible animals and makes them more susceptible to other infectious agents circulating the herd.

Implementing effective management strategies is essential for controlling BVDV and mitigating its impact on cow/calf operations. These strategies include:

a) Biosecurity Measures: Isolate incoming animals, maintain a closed herd and conduct regular testing to identify PI calves and remove them from the operation.
b) Vaccination Programs: Administering vaccines against BVDV helps prevent infections and reduces risk of reproductive losses. Producers should consult with their veterinarians to develop a tailored vaccination protocol.
c) Diagnostic Testing: Regular diagnostic testing, such as PCR or antigen capture ELISA, aids in identifying infected animals, including PI calves, facilitating their removal from the herd.
d) Herd Surveillance: Monitoring the herd for clinical signs and promptly investigating any abnormalities can aid in early detection and control of BVDV.

BVDV and PI cattle have far-reaching effects on cow/calf operations, causing economic losses, compromised reproductive performance, impaired immune function and increased susceptibility to other diseases. Proactive implementation of biosecurity measures, vaccination programs, diagnostic testing and vigilant herd surveillance are crucial for effectively managing and controlling BVDV. By taking these preventive measures, producers can minimize the negative impacts, protect the health of their herds and ensure long-term sustainability and profitability of their cow/calf operations.