Manage the mid-season rise in parasites

Manage the mid-season rise in parasites

Young cattle are at risk from the ‘mid-summer rise’ in parasite larvae on pasture unless effective control strategies, including pasture management, monitoring and targeted treatment if required, have been implemented.

This increase in parasite infectivity can occur from mid-July and lead to significant worm burdens. The impact can include slower growth, longer finishing times, impaired fertility in heifers, and an overall reduction in productivity and profitability.

Youngstock with little or no immunity to gutworms may also experience clinical disease in the form of gastroenteritis, or ‘worm scours’ which can lead to significant weight loss.

Pooled faecal egg counts during the first few months of the grazing season can help you to monitor the level of parasite infectivity on pasture, and the results can form part of any recommendation by your vet or SQP to worm cattle, or move them to alternative grazing for the remainder of the season.

It’s important to remember that unlike in sheep, FECs alone are not useful in determining worm burden levels in individual or groups of cattle.

Moving cattle to lower-risk pastures in the mid-summer, such as fields that have been used for hay or silage, can lessen the need for worming, but animals should still be monitored.

Focus wormer treatments on animals that are not meeting DLWG targets and leave better performing animals untreated, since where nutrition is adequate, and in the absence of other disease, worms are the most likely cause of missed growth targets.

For more information, talk to your vet or SQP, or visit the Beat the Parasites website.


An educational service from Boehringer Ingelheim Animal Health UK Ltd (“BI”). Further information available from BI, RG12 8YS, UK. The steerhead logo is a registered trademark of Boehringer Ingelheim Animal Health France SCS, used under licence. ©2022. All rights reserved. Date of preparation: May 2022. UI-MSP-0042-2022. Use Medicines Responsibly.


4th August 2023

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