Hunter Local Land Services confirmed last week there had been confirmed cases of nitrate and kikuyu poisoning in livestock within the region.

The humidity and rain have offered weed purslane, also known as pigweed, ample opportunity to burst to life in paddocks around the region.

Similarly, kikuyu poisoning occurs when that strain of grass thickens rapidly after a prolonged dry spell. It also has a high mortality rate.

The risk from the new growth is expected to dwindle after three to four weeks.

District vet Jim Kerr said the poisoning cases occurred in the lower Hunter where purslane had become the dominant cover.

"With such wonderful rainfall there can unfortunately be downsides for livestock owners, as hungry stock chase the green pick," Dr Kerr said.

"We're encouraging landholders where possible to maintain their feeding regimes, including introducing silage or roughage bales in Purslane or kikuyu dominant paddocks."

Dr Kerr is reminding producers Hunter Local Land Services is offering free feed testing for local producers.

"We did see numerous nitrate deaths from hay and silage during this drought from feed harvested under stress or purchased from outside sources without necessary testing," he said.

"We continue to offer this service to ensure local producers have confidence in the feed their stock are accessing.

"If you have concerns about the feed or nutrition requirements of your stock, contact Hunter Local Land Services on 1300 795 299 to speak to your local team."