RESUMEN
Adopting a 2 × 2 × 2 factorial design, this study evaluated whether continuous straw provision by racks, tail docking and gender (barrows vs. females) have an effect on the prevalence of lung lesions and oesophago-gastric ulcer (OGU) visually scored at slaughter in 635 Italian heavy pigs (169 ± 4 kg). The lung lesions were very low (72% of pigs with score 0), and were not significantly different among the experimental groups. Overall, OGU was diagnosed in 47% of the pigs. The consumption of small amounts of straw (70 g/day/pig) represented a protective factor against the onset of OGU (OR: 0.27). Barrows were more likely than females to have OGU (OR: 1.52), while no significant differences between docked and undocked pigs were detected. Nevertheless, the presence of straw acted as a protective factor particularly in undocked pigs (OR: 0.16), suggesting that in this group the absence of rooting material may have a stronger effect on welfare.