Greene County authorities on Wednesday charged six farm employees with animal abuse and neglect in connection with a video obtained by an animal rights group that showed workers abusing pigs.

The investigation came after People for the Ethical Treatment of Animals released a video about a month ago of workers at a farm in Bayard hitting sows with metal rods, slamming piglets on a concrete floor and bragging about jamming rods into the anus of sows. The farm is owned by MowMar Farms LLP of Fairmont, Minn., and supplies Hormel Foods Corp. of Austin, Minn.

Sheriff Tom Heater said warrants have been issued for the workers, who are facing charges that include livestock abuse, aiding and abetting livestock abuse and livestock neglect. Once they are arrested, they will have hearings before a Greene County magistrate.

Click here to watch the video. WARNING: Extremely graphic content.

According to a news release from Heater's office, four of the workers no longer work at the plant, while two others are still employed there.

Livestock abuse and aiding and abetting livestock abuse are aggravated misdemeanors that carry penalties including a maximum fine of $6,250 and up to two years in prison, according to the Iowa attorney general's office. The neglect charge is a simple misdemeanor and is punishable by a maximum fine of $625 and up to 30 days in jail.

PETA had sought the prosecution of 18 people on animal cruelty violations.

Daphna Nachminovitch, vice president of PETA's Cruelty Investigations Department, said Greene County authorities have been "diligent, responsive, and thorough in their investigation" and the organization trusts that a strong, solid case has been built based on its undercover video.

"Charges against any number of pig factory farmers in the nation's top pork producing state should deter the industry's workers from continuing to abuse and neglect these intelligent, playful and sensitive animals," she said in a statement.

In some instances, workers shown in the video using electric prods won't be charged because there is still debate on whether the devices are reasonable for use in livestock farming, Heater said.

PETA officials said the National Pork Board's own handbook said the use of electric prods is stressful for the animals and that they should never be prodded in sensitive areas. It says its investigation showed farm workers shocking pigs in the neck, face or crippled hind limbs.

"This conduct exceeds this cruel industry's own accepted standards and violates MowMar's written policy as well, which prohibits shocking animals," Nachminovitch said. "Again, we respect Sheriff Heater's judgment in selecting the workers and acts to be prosecuted."

The sheriff said MowMar Farms has been cooperative in the investigation. The company has said it had owned the farm for less than a month before the video came out.

"I think once the charges are out they will proceed with anything they need to do — firings, restructuring, training," Heater said.

Earlier this week, PETA released additional video allegedly showing the manager of the farm kicking and shocking an injured sow. PETA said it confirmed that the manager still works at the farm through a telephone call to the facility.

MowMar didn't indicate what might happen to the manager, but has said it has fired other workers that have been documented abusing pigs. It said its investigation is continuing.

"It is important that the investigation is allowed to complete its work to ensure that any termination and/or discipline is justified and the rights of employees are respected," the company said in a statement this week.

Heater said his department knew nothing about the abuse at the farm until the PETA footage was released last month. Asked what he thought of the video images, Heater said some of the workers' actions were "uncalled for."

"I was a farm boy. The deputy investigating is a farm boy. You don't have to beat animals ... you just have to deal with them and wait," he said.