A Study of Spatial Behaviour of Pregnant Sows Housed in Pens with Various Feeding and Dung Disposal Systems
Abstract:Ninety-six pregnant sows, previously penned in individual stalls, were housed in groups of four in pens containing three zones: a) four individual feeding stalls without rear gates, b) a communal sleeping kennel and c) a dunging area between the stalls and kennel. The feeding stalls were either long (2m) or short (l m) with barriers made of wire mesh. The daily allowance of 2.5kg pelleted feed per sow was presented either all at once (dump) or at the rate of approximately 100glmin by a manual system (trickle). Dung disposal systems were either a pit filled with sawdust-based compost, a slatted floor, or straw on a sloped concrete floor. There were two replicates of the 2x2x3 factorial design. The location of sows was observed from time-lapse video recordings taken at regular intervals throughout the 31 day experimental period.
Use of the three zones of the pens was influenced by feeding method, barrier length and dung disposal system. Overall the feeding stalls were used more with trickle than with dump feeding (P<0.05); more with long than with short barriers (P<0.00l), and most with slatted fl0rs and least with the straw system (P<0.00l). All these treatments had the opposite effects on the use of the communal kennel The use of the dunging area was not affected by feeding method or stall length but was greater (P<0.00l) on the compost compared with the other two dung disposal systems. Throughout the experimental period the use of feeding stalls decreased (P<0.00l). Circadian use of the pen zones interacted with barrier length and dung disposal system. Kennels were used most at night in pens with straw, exceeding 54minlh with half length (lm) stalls. The lowest night-time use of kennels, around 8minlh, was found in pens with full length (2m) stalls combined with either compost or slats. Ambient temperature did not have a major influence on use of pen zones.
The occupation of stalls, especially full length stalls, indicates that offering a choice between solitary and communal areas may improve the welfare of group-housed sows.