Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – 1. Introduction

This is post 1. “Introduction” of:

Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions

Marc B.M. Bracke^a, T. Bas Rodenburg^b, Herman M. Vermeer^a, Thea G.C.M. van Niekerk^a
a Wageningen Livestock Research
^b Wageningen University, Dept. of behavioural ecology

Reading guide

This is one of 8 blog posts under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:

1. Introduction, specifying the need to compare feather pecking (fp) in layers and tail biting (tb) in pigs
2. Terminology, specifying the various concepts involved in fp/tb.
3. Overview of main similarities and differences between feather pecking and tail biting
4. Farmer as a risk factor, emphasising, perhaps for the first time, that the farmer is a kind of ‘animal’ that is part of the problem (and the solution).
5. Models, reviewing available conceptual models of fp and tb, as well as presenting a new ‘face model’.
6. Disease framework, arguing that fp/tb may be regarded as a medical disorder, over and above being an abnormal behaviour per se.
7. Evolution and domestication, emphasising the need to view fp/tb as a phenomenon an evolutionary and genetic background.
8. References

The entire text (8 posts) can be downloaded as one pdf here.

1. Introduction

Feather pecking (fp) in poultry and tail biting (tb) in pigs are among the most persistent animal-welfare problems associated with intensive livestock farming. Both problems have been studied and reviewed extensively (e.g. fp: (Rodenburg et al., 2008; Nicol et al., 2013; Rodenburg et al., 2013); tb: (Schrøder-Petersen and Simonsen, 2001; Bracke et al., 2004a; EFSA, 2007b; Taylor et al., 2010; D’Eath et al., 2014; Valros, 2017)). Legislation and policy initiatives have been discouraging the continued performance of routine mutilations (beak treatment and tail docking for fp and tb respectively). However, both poultry and pig farmers generally find it difficult to stop mutilations and prevent and/or treat these injurious behaviours in intensive farming systems. Comparing fp and tb may help address these problems. However, few papers have compared the two forms of abnormal behaviour in detail. One notable exception is the fairly recent Open-Access publication by Brunberg et al. (2016). These authors discussed similarities and differences between fp and tb, and presented a general model which looks somewhat like an envelope. This publication is written for a scientific audience, and it is not easy to read for farmers and others interested in solving fp/tb such as vets, other farm advisors and NGOs. Also the ‘envelope-shaped’ model presented by Brunberg et al. (2016) is not as appealing as we would (ideally) like it to be. It mainly says that by nature both pigs and poultry are omnivorous generalists that have (had to) become production specialists via genetic selection and rearing in large-scale intensive systems applying a one-size-fits-all principle. According to Brunberg et al. both the physical and social environment (‘where you are’ and ‘who is with you’), together with animal-related factors (‘who you are’) determines ‘what you become’ in terms of fp or tb, i.e. a performer (pecker/biter), victim/receiver or a neutral animal. The authors also hypothesise that the gut-microbiota-brain axis may play a crucial role which should be investigated further. This is in accordance with the common view that fp and tb are multifactorial problems associated with the substantial discrepancy between the natural and the commercial environment resulting in a (seriously) deprived foraging (and/or feeding) motivation that eventually leads to fp/tb (and worse, i.e. cannibalism, if not curtailed adequately).

It is not entirely clear, however, why the model (figure) in Brunberg et al. (2016) should look like an envelope. When looking a bit more closely at the figure, the model appears to encompass everything (the animal, its history and its entire, physical and social, environment). Only upon more careful examination and in particular when reading the text itself do the further ramifications underlying the model become more clear. Since we feel the text may be rather inaccessible for practical application in problem solving, one objective of these blog posts, therefore, is to compare this model to other models, esp. those developed in our own organisation (Wageningen University & Research), in order to see if we can better highlight the available knowledge that should be used to (eventually help) solve the problem in practice. To this end we have also tried to make the information presented by Brunberg et al. (2016) more accessible, and we supplemented it with our personal expertise on fp/tb. It is important to emphasise, however, that the primary aim of this publication is to improve on the available conceptual frameworks to facilitate practical understanding of fp and tb so as to support solving the problem in the future. We do not, however, aim to present a tool box or cook book for solving fp/tb.

Reading guide

This was blog post nr. 1 under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:

1. Introduction, specifying the need to compare feather pecking (fp) in layers and tail biting (tb) in pigs
2. Terminology, specifying the various concepts involved in fp/tb.
3. Overview of main similarities and differences between feather pecking and tail biting
4. Farmer as a risk factor, emphasising, perhaps for the first time, that the farmer is a kind of ‘animal’ that is part of the problem (and the solution).
5. Models, reviewing available conceptual models of fp and tb, as well as presenting a new ‘face model’.
6. Disease framework, arguing that fp/tb may be regarded as a medical disorder, over and above being an abnormal behaviour per se.
7. Evolution and domestication, emphasising the need to view fp/tb as a phenomenon an evolutionary and genetic background.
8. References

The entire text (8 posts) can be downloaded as one pdf here.

Acknowledgements

These blog posts have been made possible by the Hennovation project (HORIZON 2020 ISIB-02-2014 project, Grant no. 652638).