Genome-wide association study of first lambing age and lambing interval in sheep

First lambing age and lambing interval are among the most important reproductive traits affecting profitability of sheep breeding systems. Genome-wide association studies (GWAS) were performed on estimated breeding values (EBVs) for age at first lambing and the lambing interval between first and second lambing in Lori-Bakhtiari ewes. Animals were genotyped using the Illumina Ovine SNP50 K genotyping array. Two single nucleotide polymorphisms (SNPs) associated with lambing interval were identified on chromosomes 1 and 2 (Bonferroni adjusted P-value<0.05). No SNP associated with first lambing age was detected. SNP s50067.1 on sheep chromosome 2:86798921 is within a candidate gene; ADAMTS like 1 (ADAMTSL1), known to be involved in proteolysis, peptidase activity, biological process and reproductive pathways in mammalian species. No candidate gene was detected for SNP OAR1_57568179.1 on chromosome 1. The results of the present study may provide new insights into the genomic regions involved in reproductive traits of sheep.