Washington, D.C. ? Chicken feed in some farms in Indiana contained byproducts from pet food manufactured with contaminated wheat gluten imported from China, two federal agencies said.

The Agriculture Department and the Food and Drug Administration said in a joint statement that officials learned of the link between the chicken feed and tainted pet food as part of the investigation into imported rice protein concentrate and wheat gluten that have been found to contain the chemical melamine and related compounds.

An estimated 30 broiler poultry farms and eight breeder poultry farms in Indiana received contaminated feed in early February and fed it to poultry within days of receiving it, the agencies said. Other farms will probably be identified as having received contaminated feed, they added.