Iberian pigs are traditionally reared outdoors where they feed on acorns and herbage. The capacity of volatile fatty acids (VFA) absorption could be of importance for these animals although it has never been determined. The aim of the present work was to evaluate the capacity of VFA absorption in Iberian compared with Landrace gilts fed a standard corn-soybean meal diet (160g/kg; 14.25 MJ ME/kg DM), using arterio-venous preparations. Iberian and Landrace gilts (30 kg BW; n = 4 Landrace and 6 Iberian) were used. Diets were formulated with protein of high biological value and offered at 85% ad libitum. Gilts were fasted for 24 h prior surgery. Catheters were implanted in the portal and mesenteric veins and carotid artery. Then, pigs were placed in metabolism cages and fed the diet for 6 d. On d 7, p-aminohippuric acid (PAH) was continuously infused through the mesenteric vein and pigs were offered 25% of their daily intake. Blood was withdrawn simultaneously from portal vein and carotid artery at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5 and 6 h after feeding, centrifuged for plasma harvest and stored at −20°C until analysis for PAH and VFA. Compared with Landrace, Iberian gilts had greater net portal absorption (μmol/min) of acetic acid (252 vs. 178; P = 0.000), butyric acid (17.0 vs. 12.7; P = 0.007) and isovaleric acid (10 vs. 4.7; P = 0.010), and lower of valeric acid (−8.5 vs. 12.9; P = 0.007), than Landrace gilts. No differences (P > 0.10) in net portal absorption of propionic (146 vs. 153), isobutyric (13 vs. 9) and caproic (4.5 vs. 5.5) acids were found. The greater capacity of net portal absorption of VFA in Iberian pigs could constitute a meaningful contribution to the energy requirement for maintenance and constitute an advantage when fed outdoors fibrous rich feeds.