REFERENCES
- Appleby, M.C. & Hughes, B.O. (1991) Welfare of laying hens in cages and alternative systems: environmental, physical and behavioural aspects. World’s Poultry Science Journal, 47: 109–138. doi:10.1079/WPS19910013
- Bestman, M. & Keppler, C. (2005) Jong geleerd is oud gedaan – Opfok van leghennen voor alternatieve systemen (Driebergen, Louis Bolk Insituut) [e-book]. Available: http://edepot.wur.nl/115910. Accessed 13 Jun 2013.
- Bestman, M.W.P. & Wagenaar, J.P. (2003) Farm level factors associated with feather pecking in organic laying hens. Livestock Production Science, 80: 133–140.
- Bright, A., Brass, D., Clachan, J., Drake, K.A. & Joret, A.D. (2011) Canopy cover is correlated with reduced injurious feather pecking in commercial flocks of free-range laying hens. Animal Welfare, 20: 329–338.
- British Egg Industry Council (2012) Knowledge guide – eggs facts and figures [online]. Available: http://www.egginfo.co.uk/egg-facts. Accessed 13 Jun 2013.
- Bubier, N.E. & Bradshaw, R.H. (1998) Movement of flocks of laying hens in and out of the hen house in four free range systems. British Poultry Science, 39: S5–S6. doi:10.1080/00071669888025
- Cooper, J. & Hodges, H. (2010) Effect of tree cover on ranging behaviour of free range hens, in: Lidfors, L., Blokhuis, H. & Keeling, L. (Eds) Proceedings of the 44th Congress of the International Society for Applied Ethology, p. 75 (Wageningen, The Netherlands, Wageningen Academic Publishers).
- Dawkins, M.S., Cook, P.A., Whittingham, M.J., Mansell, K.A. & Harper, A.E. (2003) What makes free-range broiler chickens range? In situ measurement of habitat preference. Animal Behaviour, 66: 151–160. doi:10.1006/anbe.2003.2172
- Gebhardt-Henrich, S.G. & Fröhlich, E. (2010) Use of outdoor range in large groups of laying hens, in: Lidfors, L., Blokhuis, H. & Keeling, L. (Eds) Proceedings of the 44th Congress of the International Society for Applied Ethology, p. 80 (Wageningen, The Netherlands, Wageningen Academic Publishers).
- Gebhardt-Henrich, S.G. & Fröhlich, E. (2012) Individuality of ranging behavior in large flocks of laying hens, in: Waiblinger, S., Winckler, C. & Gutman, A. (Eds) Proceedings of the 46th Congress of the International Society for Applied Ethology, p. 55 (Wageningen, The Netherlands, Wageningen Academic Publishers).
- Gilani, A.-M., Knowles, T.G. & Nicol, C.J. (2013) The effect of rearing environment on feather pecking in young and adult laying hens. Applied Animal Behaviour Science, 148: 54–63. doi:10.1016/j.applanim.2013.07.014
- Green, L.E., Lewis, K., Kimpton, A. & Nicol, C.J. (2000) Cross-sectional study of the prevalence of feather pecking in laying hens in alternative systems and its associations with management and disease. Veterinary Record, 147: 233–238. doi:10.1136/vr.147.9.233
- Grigor, P.N., Hughes, B.O. & Appleby, M.C. (1995) Effects of regular handling and exposure to an outside area on subsequent fearfulness and dispersal in domestic hens. Applied Animal Behaviour Science, 44: 47–55. doi:10.1016/0168-1591(95)00576-E
- Gunnarsson, S., Heikkilä, M., Hultgren, J. & Valros, A. (2008) A note on light preference in layer pullets reared in incandescent or natural light. Applied Animal Behaviour Science, 112: 395–399. doi:10.1016/j.applanim.2007.09.004
- Harlander-Matauschek, A., Felsenstein, K., Niebuhr, K. & Troxler, J. (2006) Influence of pop hole dimensions on the number of laying hens outside on the range. British Poultry Science, 47: 131–134. doi:10.1080/00071660600610591
- Hegelund, L., Sørensen, J.T., Kjaer, J.B. & Kristensen, I.S. (2005) Use of the range area in organic egg production systems: effect of climatic factors, flock size, age and artificial cover. British Poultry Science, 46: 1–8. doi:10.1080/00071660400023813
- Keeling, L.J., Hughes, B.O. & Dun, P. (1988) Performance of free-range laying hens in a polythene house and their behaviour on range. Farm Building Progress, 94: 21–28.
- Lambton, S.L., Knowles, T.G., Yorke, C. & Nicol, C.J. (2010) The risk factors affecting the development of gentle and severe feather pecking in loose housed laying hens. Applied Animal Behaviour Science, 123: 32–42. doi:10.1016/j.applanim.2009.12.010
- Mahboub, H.D.H., Muller, J. & Von Borell, E. (2004) Outdoor use, tonic immobility, heterophil/lymphocyte ratio and feather condition in free range laying hens of different genotype. British Poultry Science, 45: 738–744. doi:10.1080/00071660400014267
- Nicol, C.J., Pötzsch, C., Lewis, K. & Green, L.E. (2003) Matched concurrent case-control study of risk factors for feather pecking in hens on free-range commercial farms in the UK. British Poultry Science, 44: 515–523. doi:10.1080/00071660310001616255
- Rasbash, J., Steele, F., Browne, W.J. & Goldstein, H. (2009) A User’s Guide to MLwiN Version 2.10 (Bristol, Centre for Multilevel Modelling, University of Bristol).
- Richards, G.J., Wilkins, L.J., Knowles, T.G., Booth, F., Toscano, M.J., Nicol, C.J. & Brown, S.N. (2011) Continuous monitoring of pop hole usage by commercially housed free-range hens throughout the production cycle. Veterinary Record, 169: 338. doi:10.1136/vr.d4603
- RSPCA (2011) RSPCA welfare standards for laying hens and pullets [pdf]. Available: http://www.rspca.org.uk/ImageLocator/LocateAsset?asset=document&assetId=1232725856235&mode= prd. Accessed 17 Jun 2013.
- Soil Association (2012) Soil association organic standards for producers [pdf]. Available: http://www.soilassociation.org/LinkClick.aspx?fileticket=l-LqUg6iIlo%3d&tabid=353. Accessed 17 Jun 2013.
- Van De Weerd, H.A., Keatinge, R. & Roderick, S. (2009) A review of key health related welfare issues in organic poultry production. World’s Poultry Science Journal, 65: 649–684. doi:10.1017/S0043933909000464
- Zeltner, E. & Hirt, H. (2003) Effect of artificial structuring on the use of laying hen runs in a free-range system. British Poultry Science, 44: 533–537. doi:10.1080/00071660310001616264
- Zeltner, E. & Hirt, H. (2008) Factors involved in the improvement of the use of hen runs. Applied Animal Behaviour Science, 114: 395–408. doi:10.1016/j.applanim.2008.04.007