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

Sensors may aid early detection

A Research programme supported by Beef+Lamb NZ is investigating the potential of ‘accelerometer’ sensors for early detection of conditions such as facial eczema (FE) in sheep.

Understanding udder health

Last month we talked about why dry cow management is critical, though often overlooked. This month I wanted to dive further into the dry period’s importance to udder health.

Grasslanz scoops top science award

The Government's plan to merge the seven crown institutes presents exciting possibilities for plant technology company Grasslanz Technology, says chief executive Megan Skiffington.

Farmer input needed to combat FE

Beef + Lamb New Zealand (B+LNZ) is calling on livestock farmers to take part in a survey measuring the financial impact of facial eczema (FE).

Featured

Mixed season for Waikato contractors

Last season was a mixed bag for Waikato contractors, with early planted forage maize, planted on the dry soils around Cambridge, doing badly after germination and failing to meet potential, says Jeremy Rothery, Jackson Contracting.

National

Machinery & Products

Alpego eyes electric power harrow

Distributed by OriginAg in New Zealand, Italian manufacturer Alpego recently showed its three metre Alysium electric power harrow at the…

» Latest Print Issues Online

The Hound

Dodgy!

OPINION: If you believe Maori Party president John Tamihere’s claim that “nothing dodgy” occurred at Manurewa Marae during the last…

» Connect with Rural News

» eNewsletter

Subscribe to our weekly newsletter