Fig 1. Experimental design.

Pigs were subjected to the backtest at 5 dpn, 12 dpn, 19 dpn, and 26 dpn as indicated by the grey rectangles, resulting in 12 individual parameters considered for classification into HR and LR [12]. The grey circles indicate 1^st and 2^nd (booster) tetanus toxoid vaccinations shortly after day 0 and day 14 sampling points. Blood (n = 48) was collected at four sampling points: in naïve state (day 0), 14 days after 1^st vaccination (day 14), 14 days after 2^nd vaccination (day 28), and at slaughter (day 140); dpn = days post-natum.