Commercial farrowing systems predominantly operate indoor confinement crates or outdoor arks, which represent the two extremes of sow restraint, substrate provision and environmental control. Both systems perform similarly with regards to mortality of piglets born alive, averaging 12.30% and 12.85%, respectively (BPEX, 2009). Approximately 92% of sows in 14 European countries were farrowing in crates by the late 1990’s (Hendriks et al., 1998); the system raises welfare issues for both sows and piglets, and there is growing pressure for discontinuing its use (RSPCA, 2011; CIWF 2006). Realistic estimates suggest 25% the UK national herd are kept outdoors (BPEX, 2008), whereas in France, less than 1% of pig production is outdoors (Ifip, 2011). Indoor, commercially viable alternatives to the confinement crate are required. Despite many years of research into alternative farrowing systems, and some success with Schmid pens (Weber et al., 2007), clear
Recommendations for commercially viable alternatives have been limited, until recently (Baxter et al., 2011; Edwards and Baxter, 2010).