D'Eath, R.B.3; Amott, G.3; Turner, S. P.3; Jensen, T.4; Lahrmann, H. P.4; Busch, M.E.4; Niemi, J.K.6; Lawrence, A.B.3; Sandøe, Peter7
1 Section for Consumption, Bioethics and Governance, Department of Food and Resource Economics, Faculty of Science, Københavns Universitet2 Section for Animal Welfare and Disease Control, Department of Large Animal Sciences, Faculty of Health and Medical Sciences, Københavns Universitet3 SRUC4 Danish Agriculture & Food Council5 MTT Agrifood Research Finland6 MTT Agrifood Research Finland7 Section for Consumption, Bioethics and Governance, Department of Food and Resource Economics, Faculty of Science, Københavns Universitet
how can it be controlled in existing systems without tail docking?
Tail biting is a serious animal welfare and economic problem in pig production. Tail docking, which reduces but does not eliminate tail biting, remains widespread. However, in the EU tail docking may not be used routinely, and some ‘alternative’ forms of pig production and certain countries do not allow tail docking at all. Against this background, using a novel approach focusing on research where tail injuries were quantiﬁed, we review the measures that can be used to control tail biting in pigs without tail docking. Using this strict criterion, there was good evidence that manipulable substrates and feeder space affect damaging tail biting. Only epidemiological evidence was available for effects of temperature and season, and the effect of stocking density was unclear. Studies suggest that group size has little effect, and the effects of nutrition, disease and breed require further investigation. The review identiﬁes a number of knowledge gaps and promising avenues for future research into prevention and mitigation. We illustrate the diversity of hypotheses concerning how different proposed risk factors might increase tail biting through their effect on each other or on the proposed underlying processes of tail biting. A quantitative comparison of the efﬁcacy of different methods of provision of manipulable materials, and a review of current practices in countries and assurance schemes where tail docking is banned, both suggest that daily provision of small quantities of destructible, manipulable natural materials can be of considerable beneﬁt. Further comparative research is needed into materials, such as ropes, which are compatible with slatted ﬂoors. Also, materials which double as fuel for anaerobic digesters could be utilised. As well as optimising housing and management to reduce risk, it is important to detect and treat tail biting as soon as it occurs. Early warning signs before the ﬁrst bloody tails appear, such as pigs holding their tails tucked under, could in future be automatically detected using precision livestock farming methods enabling earlier reaction and prevention of tail damage. However, there is a lack of scientiﬁc studies on how best to respond to outbreaks: the effectiveness of, for example, removing biters and/or bitten pigs, increasing enrichment, or applying substances to tails should be investigated. Finally, some breeding companies are exploring options for reducing the genetic propensity to tail bite. If these various approaches to reduce tail biting are implemented we propose that the need for tail docking will be reduced.