Identification of genetic factors affecting tail biting in pigs

32 Pages

Author(s): Susanne Hermesch

Tail biting is a behaviour in pigs that leads to considerable pain, injury and in severe cases mortality in victims of tail biting. Further, biters start tail biting because their own welfare is compromised. The causes of tail biting are multi-factorial and the prevalence of tail biting may depend on interactions between some factors of the environment and the animal. This makes it difficult to find solutions to reduce the incidence of tail biting. So far, information about genetic factors affecting tail biting is limited partly due to the fact that data about incidence of tail biting is limited. Previous research has focussed on tail biters and only recently has first information about genetic factors affecting the incidence of victims of tail biting become available. These first results indicate that selection of pig genotypes that have a lower risk of being victims of tail biting offers an opportunity to change the predisposition of pigs to become victims of tail biting.

This project aimed to identify genetic and non-genetic factors that affect the risk of being a victim of tail biting on farms. Medication or removal of tail-biting victims was defined as a binary (0/1) trait. Pigs that were medicated or removed due to tail biting were defined as 1 while non-treated pigs that were recorded for growth and backfat received a 0.

Key findings included:

- The incidence of tail-biting victims was heritable based on medication records.

- Incidences of tail-biting victims had no genetic association with growth rate or backfat of growing pigs.

- The gender of pigs affected incidence of tail-biting victims in each herd. However, the direction of this effect was not consistent between farms.

- Incidence of tail-biting victims was higher in autumn and winter in two farms of this study.