During the recent XLVets webinar ‘Getting the Most out of the Second Half of the Breeding Season’ Kevin O’Sullivan, a vet based in Co. Cork, spoke about the management of calves during their first grazing season.

At this time of their lives, your heifer calves should have a good consistent growth rate of around 750g /day or 20kg/month. Calves should have access to high-quality grass and concentrates.

During the webinar, Kevin spoke about summer scour sydrome and described it as ‘a product of our success’.

Kevin stated that: ”The quality of grass offered to calves is much better than they previously would of been receiving, but their rumens are not developed enough to handle the quality of grass.”

He suggested that: ”Calves should have assess to roughage such as hay or straw while at grass, and a high-quality concentrate.”

What is summer scour?

Summer scour in calves is a relatively new phenomenon, whereby calves start to scour profusely, become dehydrated and losing weight rapidly a few weeks after turnout to grass.

Usually, the affected calves don’t respond to conventional treatment – it is more commonly seen in calves turned out to excellent quality nitrogen (N)-rich grass.

It is believed that an excessive intake of N leads to ammonia toxicity and the resulting scouring and wasting in the calves.

Those fed on coarser, more fibrous grass, rarely suffer from the condition.

Advice for affected calves is to re-house and feed them with a good-quality forage (silage/hay) and calf ration, for a period of four to six weeks until they recover.

Should your calves display such symptoms, talk to your vet and rule out other possible causes first, before deciding on the best approach to take to reduce the incidence, and minimise the effects of the syndrome.



Kevin then spoke about some vaccinations farmers could consider giving their calves at this time of the year: ”Farmers can give calves [the] Infectious Bovine Rhinotracheitis (IBR) vaccination once calves are over three months-of-age or older.

”Calves can also be vaccinated for leptospirosis (lepto); it only adds an extra vaccination to their lifetime, but begins the protection of your replacement heifers at a young age.”