Effect of housing on open-field test behavior of gestating gilts

Abstract

Open-field test behaviors of 36 gestating gilts maintained in either tethers, crates, loose stalls or dirt-lot ( N = 9 per treatment) were recorded. The gestation crates (C) were 0.6 m wide by 1.7 m long and enclosed by bars on all 4 sides. Tethered (T) gilts were anchored to the concrete floor by 50.8-cm chains attached to neck collars. The 0.6 × 1.7-m loose stalls (LS) opened into a slatted concrete dunging area (0.7 × 1.7 m) containing a nipple waterer which was shared by 3 loose stalls. The dirt-lot (DL) was 15.2 × 30.5 m with a 2-sided shed at one end which contained 3 feeding stalls (each 0.6 × 1.7 m) and a den area (2.9 × 1.9 m). The gilts were tested for 5 min 3 days after being bred and placed in their respective treatments, and weekly thereafter for 8 weeks. The field tests were conducted in a 3 × 12-m enclosure on pasture. Data collected included numbers of bouts and time spent chewing, grazing, snout employment (rooting, nudging and sniffing), vocalizations, standing, walking, trotting, running/bucking and distance traveled. Across all test days, the T and C gilts performed more bouts of standing and walking than did DL gilts. Crated gilts ran/bucked more than T gilts, who ran/bucked more than LS gilts, and LS gilts ran/bucked more than DL gilts. These findings suggest that an increased specific-action potential for specific innate motor patterns results from maintaining gilts in housing with minimal amounts of maneuvering and interaction room.