A total of 113 healthy mid-lactation Holstein dairy cowswere selected from a commercial dairy farm. DNA was extracted from whole blood according to Wizard® Genomic DNA Purification Kit (https://www.promega.jp/resources/protocols/technical-manuals/0/wizard-genomic-dna-purification-kit-protocol/) and subjected to genotyping at Delta Genomics (Edmonton, AB, Canada). QuantiFluor® dsDNA system (Promega, Madison, WI) was used for quantitative analysis of DNA samples, and genotyping was performed using Bovine Geneseek Genomic Profiler Low-Density 100K Beadchip (V.4, Neogen Inc, Lincoln, NE) according to the Illumina Infinium Ultra manual (Illumina, San Diego, CA). Illumina HiScan was used to scan the chip.