Figure 2

Plot of heterozygosity against proportion European introgression for all calves in our analysis. Calves that died are highlighted (red symbols). The best fit relationship between heterozygosity (H) and introgression (I) for non-inbred calves is shown (thick line: regression equation H = 0.284 (95% confidence intervals ±0.0003) + I*0.312 (±0.006), R² = 0.972). The cut-off to define ‘low’ heterozygosity calves varies with introgression, since the expected or mean heterozygosity varies with introgression. Calves that are more that 0.01 below the expected heterozygosity (blue dashed line) for their amount of introgression are defined as ‘low’ heterozygosity (see Results and Methods). The orange dashed line indicates the cut-off for introgressed calves (2^-6%).