Conjoined twin calves: a case report and cytogenetic considerations

A case of bovine embryonic duplication is described. The genetic sex of each of the conjoined twin calves was determined mainly as a result of ambiguity in the phenotypic sex of one of the twins. Chromosome analysis was based on fibroblast cultures initiated from skin tissue. Although genetically isosexual and therefore indicative of monozygosity, an alternative origin for isosexual twinning is highlighted. The probable etiology of the conjoined twinning is discussed.