Enriching the environment of growing pigs increase substrate directed behaviour and reduces harmful social behaviour directed at penmates (Horrell, 1992). The object of this study was to find out if a simple enrichment method using substrate which allowed rooting behaviour in an intensive housing system would be sufficient to maintain patterns of behaviour observed when pens were enriched more fully (Beattie, Walker and Sneddon, 1995).

In a comparative study which examined the effect of having access to mushroom compost in an otherwise barren environment there were three treatments and six replicates. The three treatments were (1) control barren pen, (2) empty horizontal rack 1800 mm x 600 mm with 30 mm2 grid size suspended above pigs' heads and (3) mushroom compost on rack as in treatment 2. Pigs released particles of compost by nosing the metal grid from below while standing or sitting. All pens had a 2500 mm x 1250 mm fibre cement board on slats under rack or in equivalent position in treatment 1.