Cattle liver abcess cases on the rise in NZ

A disease that is becoming increasingly prevalent in this country's beef industry is being put under the spotlight by a Lincoln University agricultural science PhD student.  Craig Trotter is researching liver abscesses in bull beef cattle, a disease that was virtually unheard of in this country until 15 years ago when the meat industry noticed an increased incidence of the disease reports Country-wide. Trotter says the overall prevalence of liver abscesses in bull beef herds is roughly about 10%, but in some herds it can be close to 50% and while Holstein Friesian bulls tend to be over-represented in terms of incidence of the disease, no breed is exempt.  Dr Jim Gibbs, a senior lecturer and veterinary nutrition researcher from Lincoln University, says the exact cause of liver abscesses is unknown but it is traditionally thought of as a feedlot problem associated with fast growing grain-fed animals and considered to be linked with rumen pH. It was not a disease commonly seen in grass-fed cattle until the 1990s when meat processors noticed an increasing number of affected animals being presented for slaughter, particularly Holstein Friesian beef bulls. These bulls are typically finished at around 18-months of age on intensive grass feeding systems, such as Techno-systems. Trotter has spent 18 months collecting samples from slaughtered bulls and will now use new DNA technology to identify and profile species of bacteria and sub-species of Fusobacterium that are present in the liver abscesses of this country's beef herd. The risk factors for liver abscessation in this country's bull beef industry have not yet been conclusively identified and Trotter is hoping to change all that as he progresses through his doctoral studies. As he says, if they can put a finger on the specific risk factors of the disease, then the industry can take steps to manage and prevent its effect of production losses to NZ's bull beef farmers.