DES MOINES, Iowa (AP) — An animal welfare group is demanding the U.S. Department of Agriculture take action against an animal research laboratory in Iowa over alleged negligence.

Michael Budkie is with the Ohio-based Stop Animal Exploitation NOW! He says USDA inspection records show "major violations" of the Animal Welfare Act at the Exemplar Genetics facility in Sioux Center. The company uses pigs in its research.

Budkie says the reports show 39 pigs died last September in a transport truck parked overnight. The report says an employee made an unapproved modification to the ventilation system affecting the air flow, which contributed to the deaths. Budkie says other inspection reports list "multiple incidents" of untreated health problems in pigs.

Company spokesman Troy Arends says the USDA's concerns have been addressed, including additional safety measures on trucks.