A Haplotype Diagnostic for Polled in Australian Beef Cattle

Abstract

A DNA test to assign poll genotype in Australian beef cattle breeds was released in 2010 and was based on a strong association between an allele (303) at marker CSAFG29 and the polled phenotype in Brahman and other tropical breeds. A pre-commercialisation field trial revealed that this marker was not able to accurately assign poll genotype in a number of other breeds, including Limousin and Brangus, due to the high frequency of another allele (305) that was known to be associated with both polled and horned across a variety of breeds. Using a haplotype test the current study demonstrates that there are two sources of the 305 allele in Limousin and several alleles at CSAFG29 that are associated with polled in Brangus. The haplotype based test has resulted in a much better diagnostic for polled in these breeds.