Genome-Wide Association Study (GWAS) For Left Displaced Abomasum in Highly Productive Russian Holstein Cattle

Left displaced abomasum (LDA) is a multifactorial disease of cattle that occurs mainly during the transition postpartum period and is characterized by a decrease in milk production and an increased risk of culling. Despite the widespread prevalence of this pathology, its etiology remains unclear. It is believed that unbalanced nutrition, disturbances in energy and calcium metabolism in the post-calving period lead to impaired motility of the gastrointestinal tract of cows. However, studies have been conducted confirming the hereditary nature of predisposition to this disease. Currently, the search for genetic determinants reliably associated with predisposition to LDA is actively underway. The aim of our study is to identify genetic associations characterizing the genomic variability of susceptibility to LDA in Holstein cattle in the Leningrad region of the Russian Federation. The object of the study was 360 highly productive dairy cows divided into two groups: with LDA and healthy ones (control). Fourteen candidate SNPs were found to be significantly associated with leftward displacement of the abomasum (P<1e-4). When performing functional annotation of genes containing associated polymorphisms or located close to them, candidate genes presumably associated with the development of LDA were identified: ABCB11, SRP72, RGS18, SOX4, GSG1L, FBXL19, PNPLA4.