Australia's diagnostic poll haplotype test requires reliable and varied phenotype submissions to estimate polled probabilities of haplotypes, and is dependent on unbiased sampling of the population. This paper provides a review of the effectiveness of the haplotype poll test and shows clear potential for significant ascertainment bias to be affecting the accuracy of the test, resulting from industry submission of mostly unknown or polled phenotypes, with little control over phenotype scoring accuracy. A new project targeting the supplementation with horned animals is underway to address the resulting phenotype proportions, with the aim of greatly increasing the accuracy of the test. Keywords: poll, horn, haplotype, beef.