Chewable materials before weaning reduce tail biting in growing pigs

Tail biting in pigs is a multi-factorial problem, and the early rearing environment has been proposed as a potential previously unidentified factor. The aim of this study was to test whether access to chewable material from birth to weaning reduces later tail biting. Undocked litters of 59 sows were allocated to two treatments. In the rope-and-paper treatment (N = 30), the farrowing pens were furnished from birth to weaning with 10 pieces of sisal rope and one plastic ball suspended on the wall, and the piglets were given newspaper and wood shavings twice a day. In the control treatment (N = 29), plastic ball and wood shavings were provided. The average group size was 11 piglets per pen. The piglets were weaned during week 4 after birth and transferred to growing pens, combining two or three litters from the same treatment to each pen, on average 18 pigs per pen. The growing pens were identical for both treatment groups: each had three pieces of sisal rope and a plastic chewing toy. Wood shavings were given twice a day. Behaviour was recorded on video during weeks 2, 3 and 9 after birth. Tail damage was scored during week 9. During weeks 2 and 3 after birth, oral-nasal manipulation of other piglets was less frequent in the rope-and-paper pens than in the controls (P < 0.001), while oral-nasal manipulation of objects was more frequent in the rope-and-paper pens (P < 0.001). Newspaper and sisal rope elicited more activity than the commercial pig ball (P = 0.001). During week 9, when both treatment groups had spent five weeks in identical post-weaning environments, oral-nasal manipulation of pen mates and objects no longer differed significantly between the treatment groups (P > 0.1), but there was a significant difference in tail damage. Severe tail damage (part of tail missing, or wounds with inflammation) had a mean prevalence of 9.8% in the pigs that had paper and ropes before weaning, and 32.1% in the controls (P < 0.001). Mild tail damage (healed or mild lesions) had a mean prevalence of 59.2% in the pigs with early experience of paper and ropes, and 44.7% in the controls (P = 0.002). In undamaged tails, there was no significant difference between the treatment groups (P > 0.1). It is concluded that providing chewable materials in early life has promising potential for reducing the severity of later tail biting.