2.2. Experiment 1
Ninety-six pigs [Landrace boars×(Large White×Lan-
drace) sows] weaned at day 28 with an initial BW of 7.8±
0.8 kg were used for a 48-day weaner performance study. The
pigs were penned (1.68×1.22 m) in the house with fully
slatted floors, and each pen contained one male and one
female, resulting in 12 replicates per treatment. Feed and
water via nipple drinkers was available ad libitum. The
ambient environmental temperature within the houses was
thermostatically controlled. The temperature was set at 28 °C
for the first week and was reduced by 2 °C per week to 22 °C.
Feed samples were collected each day and retained for
chemical analysis. On day 48, 48 pigs were randomly selected
(onemale or female pig per pen) and slaughtered (12 pigs per
treatment), and the two front legs were collected. Collected
legs were individually stored at −20 °C until required for
laboratory analysis.
On day 48, the remaining 48 pigs from the weaner
performance study were moved to a grower-finisher unit
with a space allowance of 0.75 m2
per pig. The pens consisted
of a 60:40 solid/slatted floor area. Pigs were grouped in four
pens and fed individually in feeding crates to record
individual feed intakes as described by O'Doherty et al.
(1999). The house was mechanically ventilated to provide an
ambient temperature of 18 °C. Pigs were fed twice daily and
individual feeding troughs were checked daily after the
evening feed. If the pig had consumed all its allocated feed,
the feed intake was increased by 100 g per pig for the
following day until feeding to appetite was achieved. The pigs
were allowed at least 1 h feeding time in morning and
evening. Animals were weighed on days 0, 48 and 118, at
which time all remaining pigs were sent for slaughter.