IT has been hailed as a lifeline, but grass sprouting across the Hunter could be poisoning some of the region's cattle.
Hunter Local Land Services confirmed on Wednesday that 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.
"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," said Dr Kerr.
Commercial beef farmer Suzanne Landers, who runs cattle in Bandon Grove near Dungog as well as the Gloucester area, described fields covered in pigweed as "a green drought".
Producers need to watch their stock closely during this period, associated with the rapidly growing young pastures, he said.
They should also move them away from fields laden with either kikuyu or purslane and add a bile of silage or roughage to give livestock an alternative to the new growth.
Anyone with concerns about feed or nutrition of their livestock should call 13000 795 299.