Evaluation of the genetic structure of Polish Red-and-White cattle to support their genetic resources conservation program

Short tandem repeats (STRs) are still powerful markers used in breeding for parentage verification of animals and ensuring meat traceability in the food sector, which is especially important for conservation breeds. The subject of the study was to establish genetic structure, based on the 12 microsatellite markers (STR), in the native Polish Red-and-White (PRW) breed, which is one of the cattle breeds in the conservation program of genetic resources and to assess whether PRW structure and a Bayesian clustering algorithm MCMC method (STRUCTURE) would enable genetic identification of this breed. The material for the study consisted of samples (ear tissue and hair roots) collected from 400 Polish Red-and-White cattle subjected to routine pedigree control at the National Institute of Animal Production in Poland. Based on the established DNA profiles in 12 STR loci and STRUCTURE analysis, a reference population was created consisting of 150 individuals, each with an ancestry assignment of≥90% to this breed. An analysis of the genetic variability of the established reference population was performed. It was found that the studied PRW population is in genetic equilibrium, with no evidence of inbreeding (F_IS=-0.022), and shows high genetic variability (Ho=0.74, PIC=0.68). The used STR markers, recommended by ISAG for parentage verification, were proven useful for pedigree analysis (CPD>0.7, PE₁=99.44%, PE₂=99.98%). The obtained results showed that the presented method can be used in the qualification of new animals for the conservation and management of breeding programs, especially in cases of pedigree errors.