Y. Hyun et al., Effects of feeder type, space allowance, and mixing on the growth performance and feed intake pattern of growing pigs, J ANIM SCI, 76(11), 1998, pp. 2771-2778
The effect of crowding and mixing on growth performance and feed intake pat
tern were investigated in growing pigs in a 4-wk study. Feeding pattern was
monitored using automated feed intake recording equipment (F.I.R.E.). A to
tal of 256 Yorkshire x Hampshire and purebred Duroc pigs (initial weight 35
.8 +/- .86 kg) were allocated to one of the eight treatment combinations in
a 2 x 2 x 2 factorial arrangement (feeder type [conventional feeder vs F.I
.R.E. feeder], space allowance [.56 vs .25 m(2)/pig], and mixing strategy [
mixed vs unmixed; mixing at start of wk 1 and 3]). Pigs were housed in grou
ps of eight, balanced for genotype and sex (barrows and gilts), and had fre
e access to a corn-soybean meal diet (17% crude protein, 3,296 kcal ME/kg).
There was no difference in growth performance between feeder types. Crowdi
ng and mixing had no effect on daily feed intake but they depressed growth
rate by 15.7 and 7.1%, respectively, and the effects of the two stressors w
ere additive. Gain:feed ratio was reduced by crowding (10.0%) but not by mi
xing. Crowded pigs made fewer (11.2 vs 15.7; SEM =.51), and longer (12.5 vs
8.9 min; SEM .41) feeder visits and had higher feed intake per visit (196.
2 vs 145.5 g; SEM = 5.94) than uncrowded animals. Mixing produced changes i
n feeding pattern in the Ist wk after mixing but not over the 4-wk period.
This study showed that crowding and mixing depressed growth rates in an add
itive manner and altered feeding behavior.