Genetic Analysis of Tail-Biting Victims in Pigs

Abstract

Tail biting is a welfare concern in pigs for both victims of tail biting and tail biters. This study aimed to estimate genetic parameters for tail-biting victims using medication records routinely collected on farm. Medication records for 771 pigs were available from 2011 until 2017 and most pigs (n = 459) needed medication due to tail-biting injury. There were 10,335 pigs with growth and backfat records that had not been medicated during this time period. Three different health traits were analysed as binary traits, defined as medication due to tail-biting injury, overall medication and medication for any health issue other than tail biting. Linear and logistic sire models were used to estimate genetic parameters. Heritability estimates for tail-biting victims were 0.09 (± 0.02) and 0.25 (± 0.09) based on a linear and logistic sire model, respectively. Medication due to other sicknesses was not heritable indicating that heritabilities for overall medication reflected additive genetic effects for tail-biting victims. There were no genetic associations between being tail bitten and growth rate or backfat indicating that current selection emphasis for these performance traits does not affect tail-biting victims. These first genetic parameter estimates of being a tail-biting victim indicates opportunities to select pigs less prone to becoming a victim of tail biting.