Population structure and admixture analysis in Frieswal crossbred cattle of India - a pilot study

The present study was aimed to assess parameters related to genetic diversity, population structure and admixture in the Frieswal crossbred cattle of India. A total of three datasets were analyzed during this study. Dataset A (n = 80) consisted of data on two purebred populations, i.e., Shorthorn (n = 35) and Brahman (n = 25) and one crossbred strain Santa Gertrudis (n = 20). The dataset B (n = 71) consisted of data on three populations that included Holstein-Friesian (n = 30), Sahiwal (n = 27) and Frieswal (n = 14) cattle. The dataset C included data on all the six breeds under study. Dataset C was used to assess the indices of population structure and genetic diversity of different breeds prior to and after LD pruning. For Frieswal cattle strain, the proportion of polymorphic SNPs and MAF levels was 84.54% and 0.24, respectively. Frieswal strain maintained appreciable genetic diversity with observed heterozygosity measure of 0.414. PCA plots for three datasets depicted effective stratification of different breeds in the respective datasets. The genomic clustering levels of Sahiwal and Holstein-Friesian were found to be 98.45 and 99.89%, respectively, while the admixture of Frieswal was estimated to be about 61.5 and 38.5% from Holstein-Friesian and Sahiwal breeds, respectively.