Friday, 18 August 2023 10:55

Time to re-evaluate pre-lamb drenching

Written by  Staff Reporters
When ewes are at an optimum BSC they are much better able to buffer a parasite challenge. When ewes are at an optimum BSC they are much better able to buffer a parasite challenge.

Sheep farmers who would normally treat ewes with drench capsules before lambing are being urged to reconsider before reaching for the next long-acting alternative.

Earlier this year the popular Bionic drench capsule was banned for use by the Ministry for Primary Industries, following concerns around the rate of release of drug from the product.

Other long-acting alternatives are available, but this could be a chance to push the ‘reset’ button on the use of these products, says vet and Beef+Lamb New Zealand Wormwise manager Ginny Dodunski.

In an era of widespread drench resistance, Dodunski says if ewes are well-fed at an optimum Body Condition Score (BCS) and are not grazing pastures heavily contaminated by internal parasite larvae, then a long-acting pre-lamb drench should not be necessary.

She says in the weeks prior to lambing and during early lactation, ewes are more prone to losing their innate immunity to worms.

How much this impacts on the ewe and her production and economic outcomes depends on a number of factors.

The first of these is the amount of feed on offer at lambing and in the weeks immediately prior to lambing.

“You will get a production response from giving ewes a long-acting drench if they are underfed, but if you really nail the feeding, get grass covers right at set-stocking and the grass coming up under the ewes after lambing, then the need for a long-acting drench product drops off.”

She says another factor to consider before picking up the drench gun is body condition. When ewes are at an optimum BSC of 3–3.5 (or above) then they are much better able to buffer a parasite challenge and farmers are less likely to get an economic response from treating those animals.

Ginny Dodunski FBTW

Wormwise manager Ginny Dodunski says if ewes are well-fed at an optimum Body Condition Score, then a long-acting pre-lamb drench should not be necessary.

“There are a lot of good reasons for maximising the number of ewes at a BCS of 3–3.5 in the flock.”

A third factor to consider is the level of worm contamination on the pasture being carried into late winter and spring.

There will be production penalties if under-stress ewes are fighting off thousands of worm larvae ingested with every mouthful.

This is more likely when ewes are grazing pastures that have been grazed by lambs over autumn and winter.

Ultimately, Dodunski would like to see routine pre-lambing drenching become irrelevant by shifting the focus to optimal feeding and management.

“A strategy for this season could be to separate multiple-bearing ewes on body condition score and only treat those who are under BCS 3 – with the aim of reducing the proportion of these ewes at pre-lamb time next year”.

More like this

Learn how Lepto could be impacting your farm

Leptospirosis is widespread on New Zealand livestock farms and a webinar, hosted by Zoetis on March 19, will provide resource, and offer insights into understanding and preventing the disease.

FE spore counts climb

As New Zealand swelters in record hot and humid conditions, dairy farmers need to be more vigilant than usual against facial eczema (FE) as spore counts start to climb.

Farmers urged to have their say on INZB funding

Farmers are being encouraged to have their say on a New Zealand Meat Board (NZMB) proposal to continue funding the Informing New Zealand Beef (INZB) genetics programme and supporting a new facial eczema research project.


Maui Milk blames supply/demand imbalance

Sheep milk processor Maui Milk says it’s one of many companies being impacted by the imbalance between supply and demand for New Zealand sheep dairy products.

Feds offer support for Maui Milk suppliers

Federated Farmers is arranging support for a small group of dairy sheep farmers in the North Island, who were told this week to stop milking by processor, Maui Milk.


Weather back to normal?

MetService meteorologist James Millward says the country’s weather patterns are now on a much more even footing.

Dealing with SNAs

As Associate Minister for Agriculture and the Environment, Andrew Hoggard has a number of delegations to focus on.

Hoggard's double Act

ACT MP Andrew Hoggard may no longer be hands-on every day at his dairy farm at Kiwitea in the Manawatu,…

Machinery & Products

Kubota tests diesel engines

Kubota last month used the UK LAMMA Show to test the water with its new 200hp, four-cylinder 09-series diesel engines.

Stone collection made easier

Usually a task given to higher horsepower tractors, stone picking looks like its moved down the horsepower charts, to anyone…

A very handy piece

Handypiece is a fully portable shearing handpiece being used by thousands of farmers and ag workers, in diverse roles across…

Killing weed seeds in a single pass

John Deere's X-Series Combine Harvesters can now be complemented by the advanced weed control capability of Redekop’s Seed Control Unit…

» Latest Print Issues Online

The Hound

Feds power!

OPINION: Your canine crusader reckons no single lobby group has had a bigger turnaround in fortunes than Federated Farmers since…

The DCM award

OPINION: This old mutt suggests the 'don't come Monday' (DCM) award (in other words, resign) must go to the heartless,…

» Connect with Rural News

» eNewsletter

Subscribe to our weekly newsletter