CINCINNATI - The Cincinnati Zoo says a prematurely born baby hippo is getting some of her mother's milk.

The zoo says the calf born early Tuesday is getting stronger, helped in part by nutrients she's now taking by bottle from milk collected from her 17-year-old mother Bibi. Zoo spokeswoman Michelle Curley said Friday the milk is supplemented with formula prepared by the zoo's nutritionist.

The zoo says 17-year-old Bibi gave birth six weeks early to the first Nile hippo born there in 75 years. The calf was 29 pounds at birth, well below the normal range of birth weight of 55 to 120 pounds and was unable to stand to nurse.

Nutritionist Barbara Henry says some of Bibi's milk will be analyzed and added to the Smithsonian's National Zoo milk repository.