North West Local Land Services (LLS) offered the grain free for the first time in its Winter Feral Pig Control Program.

A video posted to social media attests to the program's success, showing the results from a Warialda property: 148 pigs out of the local population in one night.

LLS invasive species team leader Bec Gray said this winter had been "perfect for pig control", for the unfortunate reason of drought, which meant diminishing water sources and feed.

"Feral pigs need access to water because they can't sweat, so populations tend to condense around water points, which makes it easier to target them. Also, a lot of people are feeding stock ... That attracts them in," Mrs Gray said.

However, that meant they were coming closer to livestock, increasing the risk of brucellosis and leptospirosis.

LLS district vet Ted Irwin said the prevalence of brucellosis in feral pigs was not really known, "but certainly many, many pig dogs are coming up positive with brucellosis antibodies".

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"They're mostly detected through the private vet industry ... It's a nasty disease and there's certainly been reports of humans contracting brucellosis in the North West in the last five or six years.

"[They were] a couple of vets doing surgery on dogs that were positive for brucellosis and they didn't know."

Human health not being the LLS's area, however, Mr Irwin said "what we're concerned about is if brucellosis were to enter the domestic pig market".

Mrs Gray said the LLS was considering the same offer next winter, and urged landholders to continue control efforts, preferably in co-operation, until then.

"You have to get close to 90 per cent of them knocked down, to get ahead of their reproduction rate," she said.

"It needs to be broad-scale."