An alternative weaning system (sow-controlled, SC), where the sows could leave the lactation pens at will and meet in a common pen, but the pigs could not, was studied and compared to a conventional system (CONV) where each pen housed a sow and her litter. The trial period began a week after farrowing when each system received 4 sows and litters, and stopped 4 weeks after weaning. The pigs had access to creep feed and were weaned at 5 weeks of age when the sows were moved. Twenty-two SC and 23 CONV litters were studied. Behaviour studies showed that the SC sows spent considerably less time with their pigs during the later part of the lactation period. Similarly, the number of nursing bouts per day was reduced and some sows more or less weaned their pigs before time. There were indications that the CONV sows were more disturbed by the pigs than the SC sows were. Early after weaning, the SC pigs tended (p = 0.058) to have more observations of ''eating dry feed'' as compared to the CONV pigs. Piglet plasma cortisol levels increased with age, but no significant difference in the levels between pigs in the two systems was found. The greatest increase was observed in the week after weaning.
