The effects of gestation system on sow and litter performance over a 2.5 year period were evaluated at the Iowa State University Lauren Christian Swine Research and Demonstration Farm near Atlantic, IA. Gestation housing system treatments were 1) individual gestation crates in a mechanically ventilated, partially slatted floor manure flush confinement building (C); and 2) group pens with individual feed stalls in deep-bedded, naturally ventilated hoop barns (H).

Sows were artificially inseminated in a mechanically ventilated, partially slatted floor confinement breeding barn. Sows were moved as a group to their assigned gestation housing treatment by the ninth day post-weaning. Sows were randomly assigned to gestation housing treatment when the project commenced. All first parity gilts were gestated in individual crates and randomly assigned to a gestation group after breeding for the second parity. Farrowing occurred throughout the year on a bi-weekly schedule. All sows received 2.04 kg per day of a cornsoybean meal diet. During the last trimester of gestation, feed allowance was increased to 2.72 kg. During the winter H sows were fed 25% more feed and C sows were fed 5% more feed.

Reproductive performance was summarized for 957 litters and analyzed using general linear models. Number born alive per litter was different for the two housing treatments (P0.1). H sows also weaned 0.4 pigs more per litter (P0.1). Failure to conceive was the leading reason for culling in both treatments. There was a trend for sows gestated in C to be culled for feet and leg unsoundness. H sows tended to be culled for poor body condition. Results indicate that gestating sows can be housed in deep-bedded hoop barns equipped with individual feeding stalls and achieve results comparable or superior to gestating sows housed in individual crated gestation systems.