The effect of space allowance for finishing pigs on productivity and pen hygiene

Abstract

Space allowance for housed farm animals is a contentious animal welfare issue for producers, policy makers and the public. A recent European Food Standards Agency report (EFSA AHAW panel, 2005) proposed an increase in space allowance for growing pigs. Reduced stocking rates per building cost producers in terms of reduced throughput, but might be in part compensated by improved productivity or pen hygiene. To investigate this we compared three different space allowances (0.67m2/pig, 0.73m2/pig and 0.79m2/pig), for groups of 14 finishing pigs (from 32.01kg to 91.25kg) over 65±10 days on two commercial pig farms (91–92 pens of each size, 7672 pigs). The lowest space allowance (0.67m2/pig) was close to the current EU recommended minimum space allowances of 0.65m2/pig. Wet feed was provided in long troughs with 34cm per pig of feeder space and all pens were part-slatted (1/3 solid floor).There were non-significant tendencies for improved daily gain (p=0.07) and a higher gross margin per pig (p=0.06) at the two larger space allowances. There were no significant differences in feed efficiency, lean meat, or mortality (which was very low). There was also no effect of increasing space allowance on pen hygiene in either the solid-floored lying area or the activity area in the middle of the pens. The percentage of pens with faecal soiling all over the lying area or the number of pens in need of daily cleaning, was not affected by increasing the space allowance from 0.67m2/pig to either 0.73m2/pig, or 0.79m2/pig. Pen hygiene deteriorated as pigs aged, since soiling on the solid floor and wallowing behaviour was most prevalent in the late growing period.In conclusion, there was no evidence that productivity or pen hygiene were improved by increasing the space allowance of finishing pigs from 0.67m2/pig to 0.79m2/pig in well-managed commercial pig systems, suggesting that such an increase would be costly to producers.