A surprise giraffe birth prompted zoo officials to get plasma for the calf when he wasn't getting enough nutrients from his mother.

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Kipele, a reticulated giraffe, was having trouble nursing her son after he was born Tuesday. A plasma transfusion was expected Thursday to help provide him with the nutrients that he was not getting from his mother but were needed to fight infections and boost his immune system, according to KUSA.

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"We remain optimistic that Dobby's health will improve," Denver Zoo associate veterinarian Betsy Stringer told KUSA. "However, we are taking his condition seriously. We have also provided Dobby with antibiotics to treat infection in his system and are monitoring his blood daily."

Zookeepers did not realize that Kipele was pregnant because she is on birth control. Kipele, the oldest giraffe at the zoo, was born there in August 1993.

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She gave birth to Dobby at 3 a.m. He was 5 feet tall and weighed 73 pounds. The two are being kept from public view as they bond and rest.

Dobby update! He received a plasma transfusion this am thnx to the generosity of our friends @CheyenneMtnZoo https://t.co/ai4rxZkJ1z

— Denver Zoo (@DenverZoo) March 3, 2017