Long-acting wormer in ewes boosts growth rates of lambs

The trial looked at three different groups of ewes and their lambs.

Treating ewes with a long-acting wormer prior to lambing can reduce worm burdens in lambs and improve their growth rates, according to a new study.

The trial, which was carried out at FAI Farms in Oxfordshire, involved three groups of ewes.

One was treated with a long-acting moxidectin wormer pre-lambing, one with a short-acting doramectin wormer, and one was not treated at all.

Both the untreated and short-acting wormer treated groups showed higher egg counts in lambs, while those treated with a long-acting wormer showed low worm egg counts.

FAI Farms head of science, Ashleigh Bright, said the group treated with a long-acting wormer also showed reduced pasture contamination and higher lamb growth rates than the other two groups.

She said the study also found that single-bearing ewes produced fewer eggs and contaminated less pasture compared to ewes carrying twins or triplets.

Dave Armstrong, of Zoetis, said farmers may want to consider leaving ewes carrying singles untreated and instead monitor their worm egg counts.

He said it was important sheep farmers looking at ways of reducing losses due to worms, but in a responsible way which protected the efficacy of the drugs.