LSU AgCenter animal science researcher Glen Gentry discusses his research project that is looking at using sodium nitrite as a way of eliminating feral hogs during the wildlife field day at the LSU AgCenter Bob R. Jones Idlewild Research Station near Clinton in May. Gentry said he hopes to have a product that works effectively within the next 12 months but doesn’t see a product ready for the market in less than about four years. (Photo by Johnny Morgan)

Feral hogs trapped at the LSU AgCenter Bob R. Jones Idlewild Research Station near Clinton are part of LSU AgCenter animal science researcher Glen Gentry’s research project to determine the effectiveness of using sodium nitrite as a way of controlling the animals. (Photo by Johnny Morgan)

BATON ROUGE, La. – LSU AgCenter researchers are beginning to look at baits containing sodium nitrite as a way to control the feral hog populations in the state.

After years of looking at numerous ways to control feral hogs in the state with minimal success, LSU AgCenter animal science researcher Glen Gentry said his current research project is part of a grant funded by the Pennington Family Foundation.

“With this grant, we will be looking at the use of sodium nitrite as bait that shows some promise in eliminating feral hogs,” he said.

There are three thrusts involved in being successful in the use of this chemical in dispatching the animals, he said.

“First, we need to find an effective dose to eliminate the animal,” Gentry said. “Second, we need a medium to effectively administer the dose, and third, we need a delivery mechanism to selectively target this animal.”

Gentry is testing different flavors that the pigs are attracted to, which is proving to be more difficult than first expected.

“What we are finding is that the pigs are attracted to certain flavors, such as strawberry, which they seem to like,” Gentry said. “However, the grain-based bait has some problems.”

When the sodium nitrite is added to the mix, consumption tends to drop off, he said.

“Thus we are looking at semi-solid bait forms developed by LSU AgCenter researcher Zhijun Liu in the School of Renewable Resources,” Gentry said. “Just like using gummy bears, this is a way to hide the salty and bitter taste of sodium nitrite.”

The sodium nitrite is effective in taking the oxygen out of the hog’s blood through the formation of methemoglobin. The process causes them to become drowsy, lie down and expire. At the right level, this will happen in most mammals, but deer and some other animals are less sensitive to the chemical.

“All mammals, including humans, have an enzyme that is able to change methemoglobin, which cannot bind oxygen back to hemoglobin,” Gentry said. “But pigs don’t have as much of this enzyme, so it takes less sodium nitrite to overload their system.”

“We’re at the stage right now where we’re looking for the right dose, which varies according to the size of the pig,” he said.

Research, using grain-based baits has been conducted in Texas for the past few years and in Australia before then. There is a huge feral hog problem in the Queensland area of Australia, Gentry said.

“The question on most people’s minds right now is how long before we have something that works? And I’m saying probably eight months to a year,” he said. “In my opinion we are looking at probably four years down the road before we will have something the public can use, with all of the regulatory aspects that you have to go through with EPA and FDA.”

Also as part of the project, landowners in the parishes of East Feliciana, West Feliciana and East Baton Rouge parishes will have access to traps they can check out from their LSU AgCenter parish office to use in capturing pigs on their property, Gentry said.

“Basically what will happen is a farmer who has a problem will come to the county agent,” he said. “They will set up feeders and cameras to start monitoring, and when the pigs show up they will set up the trap. We have three of these traps right now.”

Typically the plan will be to catch the pigs in an area, then move the trap, thus giving farmers some short-term relief.

“When we catch pigs in the traps, we take them to our isolation unit where we are doing the dosage trials,” Gentry said. “For landowners, when they catch them, they are to kill them. We don’t want them transported around because that is partially how we got the problem that we have now. ”

The meat from animals that have consumed the sodium nitrite should be fine for human consumption. The problem would occur if you consumed the stomach contents because it breaks down slower, he said.

LSU AgCenter wildlife specialist Don Reed said feral hogs are the biggest problem that landowners have in the state.

“So the popular saying right now is that there are two types of people in the state,” Gentry said. “There are those who have feral hogs and those who will have feral hogs.”

Johnny Morgan