Fig. 3

The linear regression curves between NDF and ADF levels in gastric content of farmed piglets living in a Dutch farm and feral piglets living in BahÃa Samborombón (Buenos Aires, Argentina). A 95% confidence bands are shown in dotted lines and coloured areas. B Regression curve for farmed piglets only: Y = 0.2538 × X–0.9917 (P < 0.001, adjusted R2 = 0.77); C Regression curve for feral piglets only: Y = 0.3996 × X + 45.79 (P = 0.001, adjusted R2 = 0.64)