In order to evaluate the productive and behavioural effects of two artificial photoperiod lengths, 56 barrows (initial BW 112.5 kg) were homogeneously allocated to two groups: group A in which animals were exposed to a 14-hour light period (70 lux) followed by 10 hours of darkness (14L:10D) and group B in which, in compliance with current legislation, pigs were exposed to a 8-hour light period (8L:16D). Pigs were restricted-fed and they were slaughtered at about 160 kg BW. The longer light period (group A) resulted in an improvement of growth and feed conversion (P<0.01). Pigs belonging to group A spent more time resting in sternal recumbency (P<0.01) and showed a reduction of some abnormal behaviours such as standing inactive (P<0.01), sitting and over investigation (sniffing) of the floor (P<0.001). From our data it is suggest that a daily 14- hour lighting time improved growth parameters and welfare condition of heavy pigs.