“Initially I tried to hide it from people,” Mr. Raza said. “When they asked what we were building, I would say I was starting a business for remodeling cars.”

Learning the ropes was a challenge. Neither the state nor the United States Department of Agriculture provided guidelines on how to build a slaughterhouse. Other slaughtering operations in the area would not allow the couple inside to study their methods.

But they had experience following food-safety standards and providing customer service: They had met while working at a Burger King, and jointly opened 10 Sonic Drive-Ins, which they have since sold.

They decided to focus on custom slaughters rather than selling predominantly to grocers, who they say are often looking just for the lowest price. The slaughterhouse was immediately successful with local Muslims, and Hira Halal Meat expanded, adding a large freezer and more storage space.

In 2009, shortly after the operation began, Mr. Raza and Ms. Chilson-Raza had a local imam come to the farm and certified that their methods met religious standards. They now raise and slaughter 6,000 to 7,000 animals a year, charging about $240 apiece, Ms. Chilson-Raza said.