Summer's damp ending has caused a flush of grass growth and higher risk of grass staggers, a Dorset-based vet has warned.

Synergy Farm Health, an agricultural veterinary business based in Dorchester, has said the rainy weather during August and September has resulted in a high risk of grass staggers, or hypomagnesaemia, in cattle and sheep. 

Hypomagnesaemia is a condition caused by low blood magnesium levels essential in many processes in metabolic functions including energy production, muscle and nerve functions. 

Vet Charlotte Mouland, of Synergy Farm Health, said: “A period of wet weather will make grass grow quickly but growing grass is low in magnesium.

“It is also low in fibre, so passes quickly through the gut, reducing time for the absorption of nutrients. Unlike most other minerals, magnesium is not released very easily from body tissues in times of high demand, so ruminants require a daily intake in their diet.

“If the daily magnesium intake is not met, cattle and sheep can develop neurological signs; high head carriage, twitching muscles, staggering and paddling. Unfortunately, more often than not, finding one dead animal or indeed multiple dead animals, is the first sign farmers will see.”

Charlotte added that grass staggers in cattle is rare but is an emergency if it happens. 

She said: “Annual incidence of grass staggers in the UK is reported at less than one per cent and recently calved beef animals make up a large proportion of those cases. 

“However, other ruminants are at high risk of developing the disease and reasonable steps should be taken to reduce that risk. 

“Farmers are telling us how quickly grass is growing now, so we need to be on the alert for the condition.”

Cattle or sheep with staggers can be dangerous to handle, and farmers are advised to call a vet immediately when symptoms appear.

Risk triggers that farmers are urged to watch out for are a change in routine that reduces daily feed intake such as bad weather or transport, grazing on young grass leys and high levels of potassium and ammonia in forage.

Pregnant and lactating animals are said to be at the greatest risk of developing grass staggers. 

Charlotte continued: “Prevention is better than cure and the Synergy team has been advising clients to focus on low-cost prevention strategies over the coming month. 

“Rather than licks, which can’t ensure that all animals have taken in enough magnesium, buffer feeding with extra roughage, such as straw or hay can be helpful to slow gut transit.”

Visit www.synergyfarmhealth.com