Wet weather throughout NSW has created strong breeding conditions for the pest animals, with mobs of up to 60 pigs being spotted in single nights.
The rest of Australia has also also seen "an explosion in feral pig numbers" according to National Feral Pig Management coordinator Heather Channon.
Dr Channon said feral pigs were widely distributed, inhabiting up to 45 per cent of Australia's land mass.
NSW Farmers wild dog coordinator Bruce Duncan said as surface water dried up, the pigs have headed for permanent water sources like farm dams, with numbers particularly high in the far west of the state.
“I've regularly seen mobs of 20 or 30 pigs — you're getting mobs of little pigs — and we've seen multiple litters from the same pig," Mr Duncan said.
"They can quickly rip through fields and fences, attack lambs and goat kids, and can bring disease as well.“
Vision captured in western NSW as part of a wild pig and dog monitoring program showed dozens of wild pigs roaming free. Some adults weighed 100kg and more.
"There are big pigs out there," Mr Duncan said.
"Pigs can come in and do a lot of damage — especially in some of the grazing country, they can dig a lot of it up and nothing grows in that country until it gets another flood through it.“
Mr Duncan said there was also increased wild dog activity, although dogs tended to be more elusive.
There are more than 23 million feral pigs in Australia, costing agriculture more than $100 million a year.
Wild dogs also take their toll on the sector, costing agencies an estimated $50 million in management costs before livestock deaths are even accounted for.
NSW Farmers president James Jackson said staying vigilant and working through coordinated pest management was vital.
"Farmers are regularly trapping more than 60 pigs in a single week. It's just a huge problem at the moment," Mr Jackson said.
Dr Channon said while there was no easy solution, land managers must continue to work together to get feral pig numbers down, which is part of the National Feral Pig Action Plan.