5 Abstract: A 2×2 factorial arrangement was used for evaluating performance traits during 16 weeks in 2 groups of 22 Yorkshire x Landrace (YL) and 13 Pelón Mexicano (PM) castrate male and female pigs 63 days old which were allotted at random into 2 rearing systems consisting of total (15 and 7 pigs) or partial confinement (7 and 6 pigs). Partial confinement included rearing animals outdoors in a grass prairie (Brachiaria brizantha) from 9:00-16:00 h. No significant differences (p