Table 1 Changes in pig production systems in Sweden during the last 30 years (Data provided by the Swedish Animal Health Service)

Gradually altered herd structure and sow number

As in many other countries in Europe, the herd structure in pig production in Sweden has changed drastically over the last 30 years. In 1980, there were 19 000 holdings with a mean of 13 sows per herd and 240 000 sows in total; in 2012, the corresponding figures were 750 holdings, 165 sows per herd and 125 000 sows in total.

Ban on antimicrobial growth promotors, 1986

Following the Swedish ban on antimicrobial growth promoters in 1986 there was a transition in pig production, from a continuous production concept into batch-wise (all-in-all-out) concepts to maintain good animal health. Based on the all-in-all-out concept, large groups of sows are weaned and bred at the same time, which in turn has increased the use of artificial insemination (AI) to about 95% of all services in 2013

Ban on dry sows in stalls, 1988

Following the ban on dry sows in stalls legislation in 1988, the sow pool concept, i.e. breeding herds with satellite nursing herds, was introduced to reduce the need for rebuilding housing facilities. In 2013, there were 19 sow pool units in Sweden, with approximately 20% of all Swedish sows.