Atresia coli in a twin calf.

: Atresia coli was diagnosed in a newborn calf. The calf was an identical twin, as evidenced by identical blood type and identical electrophoretic patterns for hemoglobin, transferrin, and amylase. The other calf was clinically normal. The calves resulted from embryo transfer and represented cleavage of a single embryo in the recipient animal. These findings indicate atresia coli in this calf was probably not hereditary.