Genome-wide association study to identify the genetic background of resistance to mastitis in dairy cattleAshja, Ali (Avtor) Dovč, Peter (Mentor) Zorc, Minja (Komentor) dairy cattlemastitisgeneticsgenome-wide association studyGWASsomatic cell countMastitis is a serious problem for the dairy industry, leading to economic losses and affecting milk quality. This study aimed to identify genetic factors associated with mastitis resistance by conducting a genome-wide association study (GWAS) for the somatic cell score (SCS). Phenotypic records of 350 Holstein Friesian cows were obtained from the Slovenian Cattle Recording Scheme Database and consisted of around 1500 milk control data from 2012 to 2023 collected on a single farm in Slovenia. Corresponding genotypic data were also retrieved from the same database and genotyped using the Illumina BovineSNP50 BeadChip (Illumina, Inc., San Diego, CA, USA). For the association study, three SCS parameters were considered, including lactation mean somatic cell score (LM_SCS), maximum SCS value (SCSMAX), and top three mean value of SCS (TOP3). After performing a GWAS using FarmCPU and BLINK models, five significant SNPs associated with the TOP3 trait in the first lactation were found on BTA 14, 15, 22, and 29. The identified SNP markers were associated with 7 known candidate genes (DNASE1L3, SLC36A4, ARMC1, PDE7A, MMP13, CD44, and IL-17RD). In addition, the identified genes were significantly enriched in the IL-17 signalling pathway. These results indicated potential genetic markers and genes associated with SCS and mastitis resistance in the Holstein Friesian cows from Slovenia.A. Ashja20252025-07-10 07:15:43Doktorsko delo/naloga170569sl