Pre-weaning mortality (especially crushing by the sow) is higher in piglets raised in a multi-litter (ML) system until 9 weeks of age than in piglets raised in a single-litter (SL) system. ML housing, however, resulted in a better transition from the pre-weaning to the post-weaning situation for the piglets (higher feed intake and daily gain, a lower frequency of damaging oral manipulative behaviour and a higher frequency of play behaviour) resulting in a higher weight at 9 weeks of age. This was shown in a research that was conducted by Wageningen UR by order of the Ministry of Economic Affairs.
The ML system consisted of a multi-suckling system with five sows and their litters before weaning, followed by housing in a pen with enrichment in a group of 40 piglets after weaning. In the SL system, piglets were housed with a crated sow before weaning, followed by post-weaning housing in groups of 10 littermates in a standard pen. Pre-weaning mortality (especially crushing by the sow) was higher in ML sows than in SL sows (3.2 versus 1.5 piglet). After weaning, ML piglets ate more (0.70 vs 0.58 kg/d) and grew faster (472 vs 381 g/d) than SL piglets resulting in a 3.4 kg higher weight (25.4 versus 22.0 kg ) at an age of 9 weeks. Feed conversion ratio was similar in ML and SL piglets.
ML piglets showed before and after weaning a lower frequency of damaging oral manipulative behaviour and a higher frequency of play behaviour than SL piglets. The performance and slaughter quality of the growing and finishing pigs was similar in the ML and SL piglets.
ML housing consisted of five farrowing pens and a communal area which was divided in an area for lying, feeding and defecating/urinating. Before parturition, at night sows were locked in the farrowing pens. After parturition, sows could freely access all farrowing pens and communal area. Piglets were kept in their farrowing pen and were given free access to the communal area when the youngest litter was 6 days of age. The sows were floor fed twice daily in the feeding area and piglets could eat from the sow feed. At an age of 9 weeks, both ML and SL pigs were moved to standard pens for growing and finishing pigs with 12 pigs per pen.