Both studies were conducted at a commercial swine
research finishing facility in southwestern Minnesota.
The facility was a naturally ventilated double-curtainsided
barn (12.5 by 76.2 m) with pit fans for minimum
ventilation. The facility contained forty-eight 3.05
by 5.5 m pens with approximately 0.58 to 0.69 m2
provided per pig for Exp. 1 and 2, respectively. Pens
were located over a completely slatted concrete floor
with a deep pit for manure storage. One-half of the
pens were equipped with a conventional 5-hole dry
feeder (STACO, Shafferstown, PA) with a feed pan
dimension of 152.4 by 17.8 by 14.6 cm (length by width
by height). The other one-half of the pens contained
a double-sided wet/dry feeder that provided both
feed and water via a 38.1-cm-wide feeder opening on
either side of the feeder (Crystal Springs; Gro Master,
Omaha, NE). All pens contained cup waterers, but pens
that contained wet/dry feeders had their cup waterers
shut off for the duration of the study so the only source
of water was the nipple waterer located under a food
shelf over the center of the feed pan inside each of the
wet/dry feeders. Pigs were provided ad libitum access
to feed and water for the duration of both studies. The
facility used a computerized feeding system (FeedPro;
Feedlogic Corp., Wilmar, MN) that both recorded and
delivered diets to pens as specified. Both Exp. 1 and 2
were conducted in the same barn at the research farm.
Experiment 1 was conducted from late spring through
summer and Exp. 2 was conducted from late summer
through fall of the same year.