Wednesday, 15 March 2017 13:55

High empty rates blamed on virus

Written by  Nigel Malthus
IrrigationNZ project manager Steve Breneger (right) addresses the Lincoln Uni Demonstration Dairy Farm open day. IrrigationNZ project manager Steve Breneger (right) addresses the Lincoln Uni Demonstration Dairy Farm open day.

Dairy farmers are being warned to keep a lookout for a common virus which may be becoming more virulent in New Zealand herds.

A continuing high herd empty rate is puzzling the Lincoln University Demonstration Dairy Farm, and some suspicion is turning onto IBR (Infectious Bovine Rhinotracheitis).

Manager Peter Hancox told a gathering of 300 at the farm’s February 23 focus day that the empty rate was 9% this spring, versus 14% last year.

“It’s an improvement but it’s still not where we want to be. We’re struggling to know why.”

Donald Arthur, of Selwyn Rakaia Vet Services, told the open day the disease struck the LUDF herd in the first week of November, when several two-year-old milking heifers presented with very high temperatures, mild coughs and discharges, the worst affected being “right off their milk”.

“We believe it was going through the herd about the time we were trying to get the cows pregnant. Particularly it seemed to be affecting the two year olds.”

However, the possible link was not clear, some of the empty cows having tested positive for IBR and others negative.

IBR is a type of herpes virus, common in NZ although local strains usually appear mild compared with overseas, where abortions and encephalitis due to IBR have been recorded.

Arthur says it is generally quite innocuous.

“But we are starting to see episodes like those we’ve seen at Lincoln.

I don’t know whether more pathogenic strains are emerging or whether they’ve always been out there and we’re recognising them.”

Arthur says that as a virus there is no treatment for the primary disease but plain white penicillin is useful against secondary bacterial infections.

Vaccination rates had been higher 20 years ago but had fallen, in part because animals testing positive for IBR could not be considered for the China export market.

“It’s something to be aware of, something that could affect herd performance, and it could even impact young stock growth as well if they get it bad enough.”

The LUDF herd is now vaccinated against IBR but Arthur is reluctant to suggest all farmers should vaccinate.

“Watch this space; if we are seeing the emergence of more pathogenic strains maybe we will have to consider it,” he says.

More like this

Lynnette Hudson Named 2026 NZ Winegrowers Fellow

Lynnette Hudson's 30-year obsession with Pinot Noir was sparked working vintage in Burgundy, seeing how subtle changes in terroir were expressed in the glass. It was, she says, "an elightening moment in every way".

Andy Macfarlane Joins AgriZeroNZ Board

Canterbury farmer Andy Macfarlane has been appointed to the board of AgriZeroNZ, the public-private partnership designed to accelerate the development and deployment of emissions reduction tools for New Zealand farmers.

Featured

Carrfields Marks 50 Years as Rural Health Programme Grows

Celebrating 50 years in the rural landscape of Central Canterbury and beyond, Ashburton-based Carrfields, has been the exemplar for all aspects of modern agriculture via its extensive range of services including supply, growing, agronomic advice and marketing.

National

Machinery & Products

Suzuki Launches Jimny Horizon

Suzuki New Zealand has announced the arrival of the latest version of its Jimny SUV, the Horizon special edition, a…

» Latest Print Issues Online

Milking It

Domestic Focus

OPINION: After hogging the media limelight for telling a NZ Chinese MP to "go back home", Winston Peters has decided…

A No-Brainer

OPINION: With fuel prices soaring, one would have expected most farmers to be reclaiming excise duty on petrol.

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter