RESUMEN
Twenty-four male Mexican hairless pigs, weighing 16 ± 1.12 kg, were used to evaluate growth performance and carcass yield in pigs fed 2 (L), 3 (M) and 4 (H) times the Metabolizable Energy (ME) required for maintenance. The pigs were assigned randomly to two experimental rearing systems (indoors and outdoors). They were fed daily according to their respective feeding regimen (FR). The indoor pigs were fed ad libitum with chopped star grass forage (Cynodon nlemfuensis). The outdoor pigs had access during 16 h to a paddock of star grass. The pigs were slaughtered when they achieve 70 kg of live weight. No significant differences between indoors and outdoors were observed in any of the variables evaluated (P > 0.05). A significant reduction of daily live weight gain (P < 0.05) was observed conforming to FR reductions (0.501, 0.438 and 0.300 kg/day for H, M and L, respectively). Days to achieve 70 kg of live weight increase (P < 0.05) as FR reduces (110, 124 and 180 days for H, M and L, respectively) were recorded. Forage consumption in pigs reared indoors reduces (P < 0.05) conforming to FR increases (0.092, 0.121 and 0.307 kg DM/day for H, M and L respectively). Fat carcass yield reduces significantly (P < 0.05) according FR reductions (24.5, 22.8 y 18.9 kg, for H, M and L respectively). Also, carcass meat yield was higher (P < 0.05) in pigs from L regimen (25.0 kg) than in pigs from M and H regimen (22.0 and 22.8 kg, respectively). Results obtained indicate a reduction in daily live weight gain conforming to daily feed intake reductions; however, improvement in carcass meat yield, accompanied with a reduction in carcass fat yield, was observed.