Concerned producers should consider moving cattle to safer pastures or providing alternate feed in kikuyu paddocks such as silage or hay.

Recent rains across the Lower Hunter and Manning Great Lakes is prompting strong pasture recovery and could lead to a repeat of last year's kikuyu poisoning outbreak that killed more than 100 head of cattle across the region.

District Vet Jim Kerr said Hunter Local Land Services has issued an urgent alert to local cattle producers after multiple cattle deaths on rapidly growing kikuyu pasture over the weekend.

"Kikuyu poisoning is still not completely understood, but what we do know is Kikuyu pasture can become poisonous when it grows rapidly after a period of prolonged dry weather," said Dr Kerr.

"The exact nature of the toxin in the kikuyu plant remains unknown and is subject to ongoing research, and may involve a fungal element.

"The decent rainfall experienced in the lower Hunter and Great Lakes districts in recent days has created suitable conditions for a repeat of last year's outbreak of kikuyu poisoning and we want producers to be alert to the risk."

Kikuyu poisoning damages the stomachs of cattle, resulting in a situation where fluid accumulates in the rumen, but can't be absorbed into the blood stream.

As a result, affected cattle become severely dehydrated, but can't drink anymore because their rumen is already full of fluid.

Consequently, affected cattle are observed to drool and 'sham drink', where they stand at troughs and dams trying to drink, but unable to do so.

In some cases there is an audible abdominal 'sloshing' when they walk because their rumen is so full of fluid, and gut pain and staggering gait may be evident before they go down and die.

What we do know about kikuyu poisoning is:

. affected kikuyu does not look any different to safe kikuyu

. affected kikuyu is likely to be less palatable to cattle, as they will avoid it if alternative feed is available

. cattle deaths occur in paddocks when the cattle have no alternative feed available

. deaths seem to stop once cattle are removed from the affected pasture, or at least when they are offered alternative feed (silage or hay)

. the risk seems to subside after 3-4 weeks.

"Cattle producers with high risk kikuyu pasture, containing little alternative feed are strongly advised to shift cattle to safer pasture or provide cattle with alternative feed if they are occupying kikuyu paddocks," said Dr Kerr.

"An additional warning, however, applies to provision of hay and silage - please introduce it gradually if the cattle are unaccustomed to it, as there have been a lot of cattle deaths during the last 12 months caused by nitrate poisoning when unadapted cattle have been given sudden access to rich hay."

Cattle producers are also being urged to report suspected cases of kikuyu poisoning to Hunter Local Land Services, as they  continue to collect samples for research.

Hunter Local Land Services thanked those who had reported stock deaths as that enables them to warn all local producers, preventing further deaths.