Fig. 2. Principal component analysis (PCA) of the bovine proteome after intramammary challenge with Streptococcus uberis. The PCA was based on 570 proteins and the plot was generated using the Partek Genomic suite. The data points refer to milk samples obtained from 6 cows at 6 time points post challenge (PC). Cows are identified by number and time points by colour, with hours PC shown in the legend.