Fresh wood reduces tail and ear biting and increases exploratory behaviour in finishing pigs

Chewing and rooting are high behavioural priorities in pigs. Lack of suitable materials can lead to abnormal behaviours such as tail and ear biting. In commercial farming, slatted floors limit the use of straw, and various point-source objects have therefore been developed. The crucial challenge is to design objects that improve welfare at minimal material and labour costs. The aim of this study was to test three low-cost objects: branching metal chains, polythene pipe crosses and fresh wood. The study was carried out on undocked growing-finishing pigs on a commercial farm in Finland, housed on partly slatted floors in 10-m2 pens of 11 pigs. The total number of pigs at the time of data collection was 780, as the farmer had removed 23 of the original pigs due to tail biting. The control pens (N = 17) had a straw rack, a metal chain and a daily provision of wood shavings. The experimental pens had the same and one of the following: the wood pens (N = 14) had horizontally suspended pieces of fresh birch wood (Ø 10 cm), 30 cm per pig; the plastic pens (N = 13) had a cross of 60-cm polythene pipes (Ø 5 cm), hanging from the ceiling; the branching-chain pens (N = 15) had two crosses of metal chains, suspended vertically; and the combination pens (N = 14) had all of the above. After 2.5 months of exposure to the objects, the pigs were video-recorded, and tail and ear damage were scored