Pestivirus hits heifer profit
CATTLE producers are reminded that better heifer performance is possible and are encouraged to invest in preventative measures against pestivirus to help optimise the reproductive outcomes from heifers.
Pestivirus, or bovine viral diarrhoea virus (BVDV), is a common virus of cattle that can cause lost pregnancies or poorly developed calves that have a short life.
However, there are a number of myths and misconceptions about the virus that need to be addressed for producers to assess the risks faced by their herd.
Neil Farmer from Comanche Grazing Co near Rockhampton knows better herd health management practices in maiden heifers can improve rates of conception and produce high numbers of top quality calves on the ground. Knowing this, protecting against pestivirus is important for the future of a herd and its ability to achieve genetic gain.
"When producers invest heavily in top bulls, artificial insemination (AI) and the time and energy of a breeding program, it can be devastating not to get a full crop of calves from maiden heifers," says Neil. "Even a small drop in conception and calving rates can have a significant negative impact on our bottom line, so it's time for producers to challenge and dispel some of the misconceptions about pestivirus."
The reproductive losses from pestivirus around joining or insemination may not be noticed until pregnancy testing or even weaning. Neil Charman from Zoetis says this can even be the case when herds have been exposed to the virus, but individual animals fail to build immunity against the disease.
"While about 90% of herds are estimated to have been exposed to this virus at some time, testing of individuals in a mob commonly shows mixed levels of immunity. This means a proportion of the herd is at risk of the effects of pestivirus" says Dr Charman.
While the impact of pestivirus is extensive and is known to cause an increased risk of abortion or calves being born with abnormalities, in some cases there may be no obvious signs.
"Pestivirus is an ongoing risk to your herd but it can be hard to identify and easy to dismiss as a non-issue for some producers," says Dr Charman. "The reality is that it actually could be affecting the reproductive performance of heifers, but a producer's ability to measure this effect depends on a number of things, such as record keeping and local benchmark data."
"Vaccination is not only reliable, but simple. While other measures like auto vaccination have been used by producers, a vaccine provides optimal protection and decreases losses due to the virus. It has also been proven to stimulate immunity in all animals treated.
Lee Taylor from Zoetis believes because most control methods require high levels of management, there is more room for failure.
"Vaccination is the easiest way to limit the threat of pestivirus and producers don't have to rely on immunity from herd exposure to the virus," says Dr Taylor.
"If producers build on the investment they have already made into their heifers by specifically protecting these high genetic value animals, they can give them the best chance of conception and produce a healthy calf first time, and every year after that," says Dr Taylor.
There's more info on http://www.bvdvaustralia.com.au.