All experimental procedures were approved by the
Purdue University Animal Care and Use Committee
(PACUC Approval No. 06-026). The sows used in this study
were returned to the Purdue University swine herd at the
end of the experiment. A total of 128 multiparious (parity
range 2–11, parity average 3.84) LandraceYorkshire
sows were used. Sows were individually marked with
different numbered bands across their backs and sides
with livestock paint (All-Weather
1
Paintstik
1
, Elk Grove,
IL, USA) for identification on the video. The paint was
reapplied as needed throughout the experiment