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Grass tetany alert: monitor your cattle

At the end of a cold, wet winter, the risk of stock losses due to grass tetany disease is currently high and livestock deaths have already been reported in the Armidale and Glen Innes districts.

Northern Tablelands Local Land Services is advising cattle producers to be alert for grass tetany symptoms in cattle and to supply magnesium supplements to avoid losing valuable cows.

Mature, well-conditioned cows with calves are often the most likely to be affected by this disease which can strike without warning.

Grass tetany is a metabolic disease in which magnesium levels decline in blood and spinal fluid. Death can be rapid and producers will commonly find a dead beast in the paddock where there had been no prior indicators of distress, although they may notice signs on the ground of the animal kicking and struggling immediately prior to death.

“We’ve already had numerous cases of grass tetany reported in the Glen Innes and Armidale districts,” said Northern Tablelands Local Land Services District Veterinarian, Nigel Brown.

Nigel has conducted post mortem examinations on several carcases with positive results for grass tetany disease expected to be returned from the lab.

“Producers are contacting us describing symptoms likely to be due to magnesium deficiency. The changeable weather is also playing havoc with livestock health, causing fluctuating magnesium levels in the blood due to stress.”

Nigel has also warned cattle producers to take precautions particularly on improved pastures that have been well fertilised.

“As the weather warms up, on heavily supered paddocks plants will grow too rapidly to absorb sufficient magnesium from the soil, which can result in dangerous magnesium deficiencies in grazing stock.”

“The message is clear – start supplying mineral supplements to stock now because it’s not uncommon for several head to die in a short timeframe,” said Nigel.

“It’s also important to make sure there is adequate magnesium in the supplement. Different varieties of supplement will contain a wide range of ingredients, although sometimes not enough of the critical ones, so check the label.”

Pastures which are low in magnesium or high in potassium are a key risk factor for grass tetany, such as grazing cereal crops or young, grass-dominant pastures. Legumes generally contain higher magnesium levels and are less likely to be problematic.

Cattle require a constant intake of magnesium, putting lactating cows at high risk as they are losing magnesium in milk.

Other stress factors, like yarding or transport, can increase the risk of grass tetany and animals can die suddenly without warning. Affected animals may show neurological symptoms like a stiff gait, agitation, apparent blindness, staggering, bellowing, and seizures, however sudden death with no obvious prior symptoms is very common on the Northern Tablelands.

If animals affected by grass tetany are identified early, rapid treatment can be life-saving. An injection of magnesium can rapidly restore correct magnesium levels.

Supplying magnesium supplements to at-risk animals can help prevent the disease. Options include loose lick blocks, spreading magnesium on hay, or mixing magnesium with grain or other supplementary feeds.

Where animals are showing neurological symptoms, contact a vet to ensure the correct treatment is provided. In cases of sudden death, Local Land Services District Vets can perform a post-mortem to confirm the cause of death.

Beef producers are advised to contact their Local Land Services District Vet or their private vet for advice on prevention strategies. For more information contact Northern Tablelands Local Land Services District Veterinarian, Nigel Brown, on 0419 434 087.

Media contact: Annabelle Monie 0429 626 326, 02 6720 8317