Bovine viral diarrhoea (BVD) is one of the most common diseases in dairy and beef cattle. Given that it lurks unseen in herds and can cause devastating losses, a more appropriate name could be the time bomb disease.
BVD is surprisingly under-reported by farmers as the symptoms are very hard to spot. This stealthy disease has a huge impact on animal welfare and can lead to devastating losses, including financially.
Persistently infected calves
Affected animals show very different symptoms and, in many cases, there is a delay between exposure to the virus and the clinical effects. Bovine viral diarrhoea is particularly dangerous when in-calf dams are infected. If an in-calf dam is exposed to the virus between 42 to 100 days of gestation and the calf is born alive, it will be what is termed a persistently infected (PI) calf.
These PI calves can shed the virus throughout their lives. Although often unthrifty, they will remain infected and, if they fail to conceive, will always produce PI calves themselves.
These animals are the most common source of infection in a herd and can spread the virus to cows during all stages of gestation, as well as to other calves, thereby continuing the cycle.
BVD affects the reproductive ability of cattle in several ways, including:
- Early embryonic death.
- Weak and sickly calves that do not thrive and may die.
- Cows with a level of immunosuppression – they are frequently ill and harder to get back in calf.
Boosting margins with enhanced livestock performance
Given that livestock producers throughout the world are finding their margins under constant pressure, optimising all areas of cattle performance is essential to maintain margins and earn capital that can be re-invested in the business.
When looking at the financial effects of BVD, a number of factors need to be examined:
- Production losses.
- Effect on fertility.
- Increased replacement rate.
- Reduced market value of livestock.
- Veterinary and treatment costs.
- Effect on concurrent disease processes.
- Increased labour costs.
- Time management.
BVD is endemic in most countries and the losses in herds of viable calves that go on to produce milk or meat should not be underestimated. It is time to take BVD seriously.
BOVELA vaccine for cattle. Lyophilisate and solvent for suspension for injection. Each 2.0 mL dose contains modified live BVDV*-1, non-cytopathic, parent strain KE-9 of at least 1x 104.0 0TCID50 and modified live BVDV*-2, non-cytopathic, parent strain NY-93 of at least 1x l04.0TCID50. Reg. no. G4283 (Act 36/1947). For animal use only. Registration holder: Boehringer Ingelheim Animal Health South Africa (Pty) Ltd. Company reg. no.: 1997/022402/07.