Final answer:
In birds, the presence of nucleated red blood cells is normal and not considered abnormal, whereas for mammals like dogs, cats, and cattle, it would be abnormal.
Step-by-step explanation:
The question asks for which species the presence of nucleated red blood cells during a Complete Blood Count (CBC) would not be considered abnormal.
Birds have nucleated red blood cells throughout their lives. In mammals like dogs, cats, and cattle, red blood cells lose their nuclei upon maturation. Therefore, seeing nucleated red blood cells in a CBC for these mammals would be abnormal.
However, for birds, it is a normal finding. The reason birds maintain the nuclei in their red blood cells is related to their specific physiological needs and evolutionary adaptations.