The performance and growth of 176 gilts in three different housing systems was observed over a 7-day trial at the Iowa State Swine Nutrition Farm. Pigs were split into one of three systems, group pens (GP) with 20 pigs in each, individual pens (IP), or metabolism crates (MC). Pigs started with an initial weight of 48.5 kg, ± 0.31, and were fed and watered ad libitum. Pigs in the GP systems had less apparent total tract digestibility (ATTD) than those in IP, which also had less ATTD than those in MC. This indicates that digestibility trials held in MC may be over-estimating ATTD of feed sources that are to be applied to a commercial or GP environment.