title: Effects of feeder type, space allowance, and mixing on the growth performance and feed intake pattern of growing pigs.
abstract: The effect of crowding and mixing on growth performance and feed intake pattern 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 total 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 2x2x2 factorial arrangement (feeder type [conventional feeder vs F.I.R.E. feeder], space allowance [.56 vs .25 m2/pig], and mixing strategy [mixed vs unmixed; mixing at start of wk 1 and 3]). Pigs were housed in groups of eight, balanced for genotype and sex (barrows and gilts), and had free 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. Crowding 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 were additive. Gain:feed ratio was reduced by crowding (10.0%) but not by mixing. 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 in feeding pattern in the 1st wk after mixing but not over the 4-wk period. This study showed that crowding and mixing depressed growth rates in an additive manner and altered feeding behavior.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Hyun
authors.forename: M
authors.initials: M
authors.lastname: Ellis
authors.forename: R W
authors.initials: RW
authors.lastname: Johnson
mesh_terms: D000821:Animal Feed; D000818:Animals; D004435:Eating; D005247:Feeding Behavior; D005260:Female; D006799:Housing, Animal; D008297:Male; D011897:Random Allocation; D013552:Swine / Q000254:growth & development* / Q000502:physiology; D015430:Weight Gain