An HSUS investigator filmed the footage, which was released earlier this week.
"For one month we had a whistle-blower filming and found hideous animal cruelty and food safety issues," Paul Shapiro, vice president of HSUS, told the Bangor Daily News. "What we saw in that video is heartbreaking."
The conditions, the group said, included "rusted wire cages, eggs covered in feces, [and] piles of dead chickens."
The facility, located in Turner, Maine, is owned by businessman Austin “Jack” DeCoster and operated by Pennsylvania-based Hillandale Farms, New England's largest egg producer. It consists of some 70 warehouses with roughly 4 million laying hens, according to a report released along with the HSUS video. DeCoster was sentenced last year to three months in jail for his role in a 2010 salmonella outbreak that sickened thousands.
According to the HSUS report, the investigation found hens confined in cages so small they could not spread their wings, hens sharing cages with decaying carcasses, and equipment covered in feces. Other animals were reportedly living with bloody prolapses and "horrendous facial abnormalities."
The HSUS investigator was told by one supervisor that "as long as it’s standing up and laying eggs, that’s all that matters," the report states.
In response to an HSUS complaint, the Maine Department of Agriculture, Conservation and Forestry announced Wednesday that it has launched an investigation into conditions at the Turner facility. It also said eggs coming from the facility are safe to eat and that there are "no reports of food safety violations at the facility now or in the recent past."
In addition to HSUS, Hillandale Farms made its own request for an investigation, Bangor Daily News reported.
"We reviewed the video, and we are investigating the practices in the barns where this footage may have been captured to ensure this is addressed immediately," Melanie Wilt, a company spokesperson, told the publication. "We have engaged our farm veterinarian, food safety and quality assurance teams to act swiftly to assure that we meet or exceed all animal health and food safety guidelines."