Linkage disequilibrium levels in Bos indicus and Bos taurus cattle using medium and high density SNP chip data and different minor allele frequency distributions

The results show higher levels of LD than previously reported, especially at short inter-marker distances of less than 20 kb, assessed through the use of the higher density panel. Negligible impact of MAF changes in the estimation of r2 was observed, supporting the use of the HD panel for LD-based methodologies even when ascertainment bias in the choice of SNPs is suspected. The 50K SNP panel indicated lower levels of LD in the first 100 kb and highly unreliable LD estimates for distances shorter than 50 kb. Overall, lower levels of LD were observed for all indicine breeds as compared to taurine breeds, with larger differences assessed in the first 100 kb, suggesting the need for use of higher SNP densities in this (sub)species when applying LD-dependent methods, as compared to most taurine breeds.