The prevalence of epitheliogenesis imperfecta in Sahiwal cattle and their crosses in a north Queensland beef herd

Epitheliogenesis imperfecta (EI) has been diagnosed in calves on a north Queensland beef cattle research station. There are five Bos indicus cross, inter se mated breed groups on the station: 1/2 Brahman, 3/4 Brahman, 1/2 Sahiwal, 3/4 Sahiwal and High Grade Sahiwal. The disease was confined to the three Sahiwal breed groups and caused calf losses over seven years from 1978 of 0.2%, 3.4% and 1.0% in the 1/2, 3/4 and High Grade groups respectively. The Sahiwal breed was identified as the origin of the gene responsible for the disease. The source of the gene within the Sahiwal breed was investigated, and several ancestors were identified as almost certainly being heterozygotes. Analyses of relationships of affected and non-affected calves to the 10 Sahiwals that were originally imported into Australia identified the one that was most likely the source of the El gene.