SAN DIEGO (CNS) - San Diego Zoo's panda matriarch Bai Yun celebrated her 24th birthday Monday, zoo officials announced.

The panda, who is a mother of six, was treated to a slushy ice cake made with applesauce and filled with chunks of apples, carrots and yams. Bai Yun's exhibit was decorated with gift boxes filled with hay and pine shavings.

The hay piles were scented by zoo keepers with her favorite scents: cinnamon, wintergreen, peppermint and spearmint, which the giant panda rubbed all over her face, zoo officials said. The panda also bobbed for apples in the pool at the panda enclosure.

Bai Yun arrived at the San Diego Zoo in September 1996 and has given birth to six cubs during her stay at the zoo. She recently returned to the front exhibit at "Panda Trek" after being on pregnancy watch for the past six months. Veterinarian staff at the zoo confirmed last month Bai Yun--- one of the oldest known pandas to give birth -- wasn't pregnant.

The San Diego Zoo is home to three giant pandas: Bai Yun, her son Xiao Liwu and her mate Gao Gao. The pandas are on loan to the zoo from China for conservation studies of the endangered species.