Use of Breed-Specific Single Nucleotide Polymorphisms to Discriminate Between Holstein and Jersey Dairy Cattle Breeds

Emphasis on livestock genetic improvement in the past decades has led to commercialization of different breeds of livestock species. Breed validation has become increasingly important to assess the safety and authenticity of livestock products in global and domestic markets. The objective of this study was to evaluate the use of breed-specific single nucleotide polymorphisms (SNPs) in discriminating between Holstein and Jersey dairy cattle breeds. Two separate resource populations were used, including a reference population consisting of 498 Holstein and 83 Jersey bull DNA samples, and a validation population consisting of 260 Holstein and 34 Jersey cow DNA samples. Five Jersey-specific and four Holstein-specific SNPs were identified and genotyped on the reference and validation resource populations. The reference population was used to validate the breed-specific SNPs used in this study and to predict the allocation efficiencies and misclassification probabilities of different combinations of SNPs. Individual animals in the validation population were allocated to either breed based on the presence of breed-specific alleles. It was found that any combination of three breed-specific SNPs had, on average, high breed allocation efficiency of >95% and low misclassification probability of <5%. In conclusion, this study demonstrates a simple, yet effective, method of using breed-specific SNPs to discriminate between Jersey and Holstein cattle breeds.