FARMERS are being reminded to monitor lactating suckler cows for magnesium deficiency at turnout - it's a time when they're particularly vulnerable to grass staggers.

But, the likelihood of the disease taking hold can be easily avoided by assessing and managing on-farm risks, said David Thornton, Rumenco's technical manager.

"Magnesium is not easily mobilised from stores in the body, hence the importance of nutrition management to ensure adequate blood magnesium levels of 2-3mg per 100ml of blood are maintained.

"In addition, rapidly growing spring grass generally has a low magnesium content of between 0.1 and 0.2% in dry matter," says Mr Thornton.

"These factors, combined with the added challenge that grazing has a low dry matter content leading to it passing through the rumen quicker. And, the extra stresses put on the animals from lactation and turnout, can result in very low levels of available magnesium in the blood resulting in clinical symptoms.

"To avoid the risk of staggers, I'd advise providing cattle with long fibre sources, such as hay or silage, which pass more slowly through the rumen. Also, ensuring cattle have access to a magnesium supplement is vital to alleviate low magnesium levels at spring pastures," he added.

Introducing a lick supplement two to three weeks prior to turnout, and placing licks near water troughs will also help encourage intakes once cattle are turned out.