Environmental enrichment of intensive pig housing using spent mushroom compost

In a comparative study which examined the effect of having access to mushro om compost in an otherwise barren environment there were three treatments a nd six replicates. The tree treatments were (T1) control barren pen providi ng 0.7 m(2) per pig with fully slatted floor, (T2) empty horizontal rack su spended above the pigs' heads and (T3) mushroom compost on rack as in treat ment 2. Pigs released particles of compost from the rack by nosing the meta l grid from below. Almost twice as many pigs with access to mushroom compos t (T3) nosed the rack (P<.001) and the ground below the rack (P<0.001) as p igs which had a rack with no mushroom compost (T2). Fewer pigs with mushroo m compost were involved in behaviours directed at penmates such as nosing, biting and chewing penmates than pigs in treatments 1 and 2 (P<0.001). In a ddition fewer pigs in T3 were involved in feeding behaviour than in T1 and T2 (P<0.05). Percentages of tail-bitten animals which had to be removed wer e 11 and 24 for T1 and T2 respectively while T3 had <1% removed because of tail biting (P<0.05). Apparent food intake was higher(P<0.05) and food conv ersion ratio tended to be poorer in T1 (P=0.1). It is suggested that pigs w ill redirect rooting behaviour towards penmates and the feeder in the absen ce of any rooting substrate. Adding substrate to commercial finishing pens reduces this redirection of behaviour and improves welfare by minimizing in jury through tail biting.