Photo provided by LSU -- Feral pigs are caught on surveillance video feeding in the wild. The growing feral hog population is causing millions of dollars of damage to agriculture across the southeastern United States.

In Louisiana's ongoing fight against invasive wild swine, state officials are hopeful that a new product — a toxic bait, or hog poison — may help finally turn the tide against the porcine menace.

The bait, which the U.S. Department of Agriculture is field testing in Texas and Alabama, could help curtail a population that has been steadily increasing across the state, said Dr. Jim Lacour, a veterinarian with the Louisiana Department of Wildlife and Fisheries.

The state's population of wild swine is about 700,000, Lacour said. Nationwide, there are about 6 million of the animals spread across 35 states, according to the U.S. Department of Agriculture.

Wild hogs are found in every Louisiana parish but are particularly numerous in the Florida Parishes, central Louisiana and the coastal regions, Lacour said.

In some areas, they are losing their natural timidity around people. Campers at Fontainebleau State Park near Mandeville have seen hogs nosing around picnic tables and rooting through trash with campers sitting just a few feet away.

"They're a mammalian cockroach," Lacour said.

They are also destructive. A 2016 LSU AgCenter report estimated that wild swine caused $55 million in direct damage to agricultural production in Louisiana in 2014 and 2015. Soybeans were the hardest-hit crop, with about $18 million in losses.

The USDA estimates that feral hog damage to crops around the country totals $190 million each year.

Mike Strain, the state's commissioner of agriculture and forestry, is hopeful that the new toxic bait can help reduce the pig population.

The product being tested by the USDA is a peanut-based paste that contains sodium nitrite, a common food additive. If eaten in high enough doses, the sodium nitrite inhibits the ability of the hog's blood to carry oxygen; it can be fatal.

"If they are affected by it, they literally just go to sleep," Strain said. The effects are said to be similar to carbon monoxide poisoning.

But he's not certain it will work on the wily swine. "There are some concerns that the feral pigs won't eat enough to be fatal," he said.

There are also worries about the bait's delivery system. For the field trials, it's going to be put in containers with magnetic lids. The lids are supposed to be hard enough to open that only feral pigs will be able to do it, not other animals like raccoons.

But that means the devices are not being tested in any areas where there are black bear populations, which will limit its use in parts of Louisiana.

The delivery system will have to be very carefully vetted before it can be used widely, Strain said.

And even if the system does work, it may not be enough to stem population growth.

State wildlife officials have designated feral hogs as "outlaw quadripeds," meaning that hunters on private land can shoot them 365 days of the year, trap them and use dogs to hunt them. They can even be shot from a helicopter with a permit.

"We are currently harvesting about 350,000 per year," Strain said. In order to reverse the population growth, the state would have to kill 70 percent of the population, or close to 500,000, every year. 

Nationwide, the USDA is spending approximately $20 million per year to control the population. But the animals are incredibly hardy and adaptive, Strain said.

They are also prolific. Hogs reach sexual maturity at six months and can produce litters of six to 13 piglets twice per year. It's been estimated that one pig can turn into 300 in just three years' time.

They are omnivores that consume all available food, from acorns to deer fawns. They spread diseases such as brucellosis, trichinosis and pseudorabies. Their rooting can destroy acres of crops. 

"They are bigger, meaner and more aggressive" than other animals, Strain said. "They destroy the environment they are in."

Follow Faimon A. Roberts III on Twitter, @faimon.