Herbs and legumes can help sheep performance

Benefits: Mixture also helps to reduce the need for wormer controls

Adding a mixture of herbs and legumes into grazing swards can help improve sheep performance and reduce the need to use wormer controls.

Scientists at University College Dublin (ECD) have found that compared to perennial rye grass grazing, adding herbs to multi-species swards could reduce days to slaughter by more than 10.

What’s more, herb-rich multi-species swards could slash the need to use anthelmintics to tackle worm issues.

UCD scientist Cornelia Grace said the study aimed to look at the impact of grazing sheep on perennial rye grass compared with multi-species swards.

The researchers also wanted to investigate the difference adding herbs to multi-species swards could have.

Funded by Ireland’s Department of Agriculture, Food and the Marine, the study involved creating four ‘farmlets’, which were each stocked with 30 twin-rearing ewes.

The farmlets contained either perennial rye grass swards, perennial rye grass with water clover swards, a six species sward (two grasses, legumes and herbs), or a nine species sward (three grasses, legumes and herbs).

Lambs were weaned at 14 weeks and drafted for slaughter at 45kg, during which time they were weighed every two weeks and faecal egg counts were measured.

Lambs were treated with anthelmintics once the group parasite burden reached a set threshold, and the scientists measured the days between each treatment.

“We found that adding herbs to multispecies swards increased weaning weights, with lambs on rye-grass swards weaning at 30.6kg, and those on six species swards weaning at 32.6kg,” said Ms Grace.

“The sward type also had a significant effect on days to slaughter, with lambs reared on perennial rye grass registering 175 days, compared to 162 and 164 days for the six and nine species swards, respectively.”

The number of worm treatments, and the time between the first and second treatments, was also significantly lower on herb-rich multi-species swards, Ms Grace said.

“Profitability and sustainable control of parasites are significant challenges for sheep farmers, so creating more diverse swards is a simple way of improving performance, reducing the need for wormers, and increasing profitability,” she added.

The study looked at the impact of grazing sheep on perennial rye grass compared with multi-species swards.