Zoetis veterinarian, Patricia van Veen, informed the seminar that stomach worms continue to have a significant impact. An EU-wide study published in 2020 estimated that gutworm, lungworm and liver fluke infections cost the UK cattle industry an estimated £227M* annually.
Her key take-home message centred around the benefits of working as a team with your advisors and prescribers to optimise the outcome for the grazing season. The success of the grazing season starts with a healthy animal in good condition at turn-out, one that can respond well to the worm challenges during grazing. It is important to find a balance between acceptable levels of worm burdens, pasture contamination, immunity to worms and treatments.
The two main parasites involved in parasitic gastro-enteritis (PGE) in cattle are Ostertagia ostertagi and Cooperia oncophora. Youngstock can show signs of diarrhoea, weight loss and decreased feed intake during PGE in their first grazing season.
The veterinarian also confirmed that disease from lungworm remains unpredictable and can result in severe disease and death. Youngstock at grass for the first time are more predisposed to lungworm disease until immunity has developed. Lungworm vaccination is an important tool on any farm with a history of lungworm disease.
The life cycle of the parasite is facilitated by fungi that inhabit dung pats. They act to physically disperse larvae onto the surrounding grass and allow larvae to travel over large distances into neighbouring fields.
The risk of disease from lungworm infection is highest when rain follows a dry spell in late summer. The rain and humidity disperse worms from dung pats and a sudden increase in larvae results in sudden severe worm burdens and lung damage.
If lungworm has been a problem on a farm, it is important to monitor cattle closely during these periods. Any sign of coughing in late summer should be taken seriously, and youngstock should be moved from the field to safe grazing. Treatment should be considered carefully, as the worm treatment of choice can be different for individual farms.
Patricia van Veen again.
Worming strategies can be planned around those times during the grazing season when cattle are gathered for routine management procedures. Planned grazing should also allow for safe pasture to be available at high-risk times, as mentioned for lungworm.
“Taking dung samples and for faecal egg counts (FEC) will deliver important information on the need and timing of stomach worm treatments.
Quarantine measures are particularly important where store cattle are bought-in. Knowledge of the history of cattle can help you and your advisors decide which treatments and vaccinations are needed to help protect your own and the incoming stock.
Looking to the future, Patricia notes that anthelmintic resistance will become an increasing challenge.
“A lot of work is being done by groups like COWS, to develop guidance for farmers and their prescribers. There are some useful tools available to help understand the different wormer groups; white 1-BZ, yellow 2-LV or clear 3-ML. We should use anthelmintics responsibly so that they remain effective into the future.
Reference:
* Charlier, J., et. al. Preventative Veterinary Medicine. 2020
