Fig. 1

Heatmap of the phenotypic correlation matrix for wavenumbers in Danish Holstein. The upper and lower triangle are identical. Seventeen blocks of strongly positively correlated neighbouring wavenumbers are indicated with black dashed square boxes. The upper left corner represents wavenumber 3008 cm^− 1 and wavenumber group 1, and the lower right represents wavenumber 925 cm^− 1 and wavenumber group 17