PITTSBURGH (AP) - A Pittsburgh zoo says a baby elephant that had a feeding tube inserted to help it gain weight has been euthanized.

Officials at the Pittsburgh Zoo & PPG Aquarium announced Wednesday that the unnamed female calf had died.

The calf was born about 30 days prematurely in May, and at 184 pounds (83.6 kilograms), it was about 52 pounds (23.6 kilograms) underweight at birth.

The calf's mother at the zoo's International Conservation Center in Somerset County rejected the calf, forcing keepers to feed it a combination of formula and elephant milk pumped from another female.

"Our hearts are broken, it's just devastating," says Dr. Barbara Baker, President & CEO of the Pittsburgh Zoo & PPG Aquarium. "She touched so many people in such a short time. We did everything we possibly could to care for her, but unfortunately in the end, it just wasn't enough."

Teething caused the calf to stop eating. It responded well to the feeding tube inserted earlier this month, but it didn't gain enough weight.