PORTLAND – Congressional investigators looking into problems at an Iowa farm owned by Austin “Jack” DeCoster that is at the center of a recall of 380 million eggs will get to see the promising results of stricter regulations at egg farms in Maine.

Investigators requested inspection records and documents from DeCoster for more than a dozen farms and farm-related companies believed to have ties to him, including Maine Contract Farming, Quality Egg of New England, Dorothy Egg Farms LLC and Mountain Hollow Farms, all in Maine.

The House Energy and Commerce Committee is focusing its investigation on the problems at DeCoster’s farm in Iowa, but it cast a wide net when seeking information.

No commercial farms in Maine have tested positive for salmonella since October 2009, said state veterinarian Don Hoenig, who pushed for the stricter regulations.

Maine has regulations that go beyond federal requirements when it comes to egg safety. For example, Maine requires vaccinations of young birds for salmonella, follow-up tests to ensure the vaccinations worked, and stepped-up inspections and cleaning of buildings, Hoenig said Thursday.

“I wouldn’t hesitate to buy eggs from any of the Maine farms. Period,” he said.

Maine Contract Farming, which is owned by the DeCoster family, feeds and cares for 5 million hens on the site of Quality Egg of New England in Turner, which is owned by a DeCoster associate and takes care of transportation. Together, the operations comprise the largest egg farm in New England.

Winthrop-based Dorothy and Leeds-based Mountain Hollow have lease arrangements with DeCoster’s operations, said Hinda Mitchell, spokeswoman for Quality Egg of New England.

Dorothy distanced itself from the investigation and touted Maine’s regulations. “The Maine monitoring program of constant testing, thorough cleaning and mandatory vaccination of hens is stricter than even the new requirements from the FDA (Food and Drug Administration),” said Ann Murphy, a Dorothy spokeswoman.

As in Iowa, DeCoster has a long history in Maine.

In April 2009, what was then known as the DeCoster Egg Farm in Turner made headlines over a video documenting mistreatment of hens. Before that, his farm was investigated by the state for denying laborers access to teachers, social workers and doctors, and was later fined $3.6 million by the federal government over workplace conditions.

While DeCoster has a history in Maine, there have been no human salmonella cases linked to tainted eggs from his operations in Maine, or from any other farm operating in the state during the past 20 years, Hoenig said.

Maine was proactive in dealing with salmonella that appeared years ago in some commercial henhouses, prompting a series of strict regulations, Hoenig said.

Unlike federal regulations, Maine requires egg-laying hens to be vaccinated not once but twice for salmonella, and they’re tested in Maine to ensure that the vaccine was properly administered, Hoenig said. Maine also has requirements for cleaning henhouses in between flocks.

Hoenig believes Maine’s farms will stand up to scrutiny because of the stricter regulations.

“That’s not to say we’re letting down our guard or becoming complacent. We’re stepping up because we realize we need to continue to be vigilant,” he said.