Productivity of mother pigs is lower, and mortality greater, in countries that still confine them in gestation crates.

Background: For decades, pig farmers have used gestation crates - small metal enclosures about two feet wide - to confine pregnant sows (female breeding pigs). Gestation crates physically restrain sows for most of their life, preventing them from walking or even turning around. Millions of females are still housed in these systems. Growing societal concern about animal welfare has been pressuring the industry for change, with recent legislation in the European Union and California restricting the use of crates. Still, the notion that gestation crates negatively affect sow welfare has been challenged by producers in regions where crates are widely used, who argue that, by facilitating health monitoring and preventing aggression, crates lead to lower sow mortality and higher piglet outputs per sow. We address these claims by comparing sow mortality and performance across countries with different housing systems. Methods: To this end, we use publicly available data from InterPig, a network of pig production economists in 17 countries that provides internationally harmonized methods for meaningful comparisons of national production data. Results: The results show that sow mortality is significantly higher, and annual pig production per sow significantly lower, in those countries where gestation crates are still the norm compared to countries in the European Union, where use of gestation crates is restricted to up to four weeks after insemination. Conclusions: Claims of higher mortality and reduced productivity per sow in crate-free systems are not substantiated by this data. This evidence should be considered in policies affecting the welfare of breeding pigs.