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.