Tuesday, 25 February 2025 12:55

Anti-parasite drugs 'affect lamb development'

Written by  Staff Reporters
AgResearch scientist Melissa Hempstead says they found that anthelmintic products in ewes affected lamb development. AgResearch scientist Melissa Hempstead says they found that anthelmintic products in ewes affected lamb development.

AgResearch scientists have collected the first known data showing behavioural developmental impacts on lambs whose mothers were treated with long-acting drugs for parasites.

Against a backdrop of increasing resistance among livestock internal parasites to commonly used drenches in New Zealand, the scientists set out to look at what effects of anthelmintic use may be passed from the treated ewe to her lambs.

Treatment of pregnant ewes with persistent macrocylic lactone anthelmintic products is common in some countries, including New Zealand, with the intent of reducing negative impacts of parasites on production, health and welfare.

"What we found was evidence in some cases of delayed neonatal lamb behaviour associated with anthelmintic use in the mother, which is the first time we know of this being recorded," says AgResearch scientist Melissa Hempstead.

"Now we need to do further research to build on these initial observations, and to help understand what the implications are for the survival and performance of these lambs from the neonatal stage."

In an experiment set up by Hempstead and her colleagues, sixty mixed-age pregnant twin-bearing ewes were split equally into three groups with different treatments: moxidectin 2-3 weeks prior to lambing, abamectin and albendazole 2-3 weeks prior to lambing, or a control group with no drug administered.

The ewes were housed indoors four weeks before they were expected to give birth and behaviour of both ewes and lambs was monitored using video cameras. Ewe and lamb behaviour was evaluated for three hours after the birth.

"There was no evidence that abamectin and albenzadole affected ewe or lamb behaviour," Hempstead says.

"However, we found that neonatal lambs from ewes administered moxidectin tended to be slower to shake their heads after birth and were slower to attempt to stand compared with lambs from untreated ewes."

This latest research builds on efforts by AgResearch's Parasitology Team to support farmers and industries grappling with the challenge of managing internal parasites in livestock, and how best to address it.

Rising resistance to drug treatments means that other management practices need to be considered and investigated by researchers.

Read more about the lamb behaviour research at: https://www.sciencedirect.com/science/article/pii/S0168159125000528 

More like this

New genetic tool for beef farmers

Beef + Lamb New Zealand (B+LNZ) has launched a powerful new tool to help commercial beef farmers select the best bulls for their farm businesses.

Wool-shedding sheep key to remote farm operation

For Marlborough Sounds farmer Noel Moleta, farming hair sheep that need no shearing is one of the keys to running a low-input, low-intervention operation in a difficult and highly remote location.

Improving your herd long-term

With a higher forecast payout, falling interest rates, and renewed confidence in the dairy industry, farmers can move beyond day-to-day survival and plan how they can improve their herd long term.

Featured

Gongs for best field days site

Among the regular exhibitors at last month’s South Island Agricultural Field Days, the one that arguably takes the most intensive preparation every time is the PGG Wrightson Seeds site.

Feed help supplements Canterbury farmers meet protein goals

Two high producing Canterbury dairy farmers are moving to blended stockfeed supplements fed in-shed for a number of reasons, not the least of which is to boost protein levels, which they can’t achieve through pasture under the region’s nitrogen limit of 190kg/ha.

National

Machinery & Products

Buhler name to go

Shareholders at a special meeting have approved a proposed deal that will see Buhler Industries, the publicly traded Versatile and…

Grabbing bales made quick and easy

Front end loader and implement specialist Quicke has introduced the new Unigrip L+ and XL+ next-generation bale grabs, designed for…

» Latest Print Issues Online

The Hound

Risky business

OPINION: In the same way that even a stopped clock is right twice a day, economists sometimes get it right.

Should've waited

OPINION: The proposed RMA reforms took a while to drop but were well signaled after the election.

» Connect with Rural News

» eNewsletter

Subscribe to our weekly newsletter