As we enter the second half of the grazing season, beef farmers must turn their attention to parasite activity.
Parasites such as roundworms and fluke can be an issue at this time of the year, especially with these damp and warm weather conditions.
Roundworms include lungworm, also known as ‘hoose’, which is a respiratory disease caused by the parasite Dictyocaulus viviparous.
Younger animals are more prone to contracting these parasites, as cattle typically develop immunity to these parasites over one or two grazing seasons.
Suckler animals are often at a greater risk of disease or ill-thrift from roundworms in their second grazing season in comparison to dairy calves, as they generally have limited exposure to the parasite in their first year.
Adult lungworms live in the lungs and lay eggs, which are coughed up and swallowed. Older animals often act as carriers over the winter, as some adult worms will survive in the lung.
The eggs released in the lungs hatch and develop into stage one larvae, passing through the intestine before being released through dung.
The larvae then develop in the dung, before splashing onto grass during rain, from where they will be ingested and the cycle begins again.
Symptoms
Lungworm infection can be a severe and often fatal disease, causing milk yields to drop, a dip in fertility, and extended calving periods.
Cattle with lungworms often develop a cough or have trouble breathing. especially when being moved. Many cattle may have their head and neck stretched out, their mouth open, and their tongue sticking out.
Gutworm symptoms can be harder to spot in cattle, but a reduced appetite, lack of thrive, and scouring are the most notable.
Second grazers will have some immunity built up, making the chance of a clinical disease less likely than a subclinical disease.
Dealing with parasites
Setting up a targeted parasite control plan can be extremely beneficial to your farm this summer.
To reduce the risk of your animals getting infected, evaluate the parasite risk of a pasture and match it with how naïve your stock is.
Farmers should also have a strategic dosing plan for mid-summer, however, using faecal egg counting can help establish if your cattle need to be treated and what treatment is needed without creating wormer resilience.
While faecal egg counting is useful for gutworms, it is not reliable in detecting lungworm.
If a lungworm infection has been identified, treatment with one of the three classes of anthelmintic (white, yellow, clear) will be required.
Treatment of the whole group should be done quickly after the appearance of clinical signs to limit the impact of the infection.
If treatment for lungworm is delayed, cattle are at risk of lung damage which can become severe and untreatable.
Contact your vet for treatment advice if a heavy infection is suspected.
