Duration of confinement and pen-type affect health-related measures of welfare in lactating sows

K Maschat; M Dolezal; C Leeb; B Heidinger; C Winckler; M Oczak; J Baumgartner

doi:10.7120/09627286.29.3.339

Duration of confinement and pen-type affect health-related measures of welfare in lactating sows

Published online by Cambridge University Press: 01 January 2023

K Maschat ,

M Dolezal ,

C Leeb ,

B Heidinger ,

C Winckler ,

M Oczak and

J Baumgartner

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K Maschat*: Affiliation:
Institute of Animal Welfare Science, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
M Dolezal: Affiliation:
Platform for Bioinformatics and Biostatistics, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
C Leeb: Affiliation:
Division of Livestock Sciences, Department of Sustainable Agricultural Systems, University of Natural Resources and Life Sciences (BOKU), Gregor-Mendel-Strasse 33, 1180 Vienna, Austria
B Heidinger: Affiliation:
Agricultural Research and Education Centre Raumberg-Gumpenstein, Department of Husbandry Systems, Technique and Emissions, Altirdning 11, 8952 Irdning-Donnersbachtal, Austria
C Winckler: Affiliation:
Division of Livestock Sciences, Department of Sustainable Agricultural Systems, University of Natural Resources and Life Sciences (BOKU), Gregor-Mendel-Strasse 33, 1180 Vienna, Austria
M Oczak: Affiliation:
Institute of Animal Welfare Science, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria Precision Livestock Farming Hub, Institute of Animal Welfare Science, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
J Baumgartner: Affiliation:
Institute of Animal Welfare Science, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
*: * Contact for correspondence: kristina.maschat@vetmeduni.ac.at

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Abstract

Temporary crating is considered as a step towards improved welfare in lactating sows. Therefore, the aim of this study was to investigate effects of confinement period (CP) and farrowing pen-type (PT) on health-related measures. Four hundred and thirteen sows were kept in five PT with four CP each: CP 0-sows were not confined; CP 3-sows were crated postpartum for three days; CP 4- and CP 6-sows were crated from a day prior to expected farrowing until day 4 and 6 postpartum, respectively. Alterations in different body regions were recorded when sows were moved to the pens and in weeks 1, 3 and 4 postpartum. CP 6-sows displayed significantly more lesions on their back than CP 0- and CP 3-sows. Odds ratios of teat lesions were markedly higher in CP 4-sows than in all other CP. Pen-type P (Pro Dromi) resulted in more neck/back/body side injuries, claw horn changes and lame sows compared to all other PT. High odds ratios were also found for neck injuries in PT K (Knick), shoulder sores in PT K and T (Trapez), injured teats in PT F (Flügel) and body side injuries in PT S (SWAP). The types of lesions found in the present study are similar to those reported for crates caused by pen structures. While an overall assessment of pig (Sus scrofa domesticus) production husbandry systems must also take piglet welfare into account, this study showed that keeping confinement periods as short as possible improves sow welfare and systems should be adapted to also cater for the needs of sows.

Keywords

animal welfare farrowing systems pathological alterations skin lesions, Sus scrofa domesticus temporary crating

Type: Research Article
Information: Animal Welfare , Volume 29 , Issue 3 , August 2020 , pp. 339 - 352

DOI: https://doi.org/10.7120/09627286.29.3.339 [Opens in a new window]
Copyright: © 2020 Universities Federation for Animal Welfare

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References

Anil, L, Anil, SS and Deen, J 2002 Evaluation of the relationship between injuries and size of gestation stalls relative to size of sows. Journal of American Veterinary Medical Association 221: 834–836. https://doi.org/10.2460/javma.2002.221.834 CrossRef Google Scholar PubMed

Anil, SS, Anil, L and Deen, J 2005 Evaluation of patterns of removal and associations among culling because of lameness and sow productivity traits in swine breeding herds. Journal of American Veterinary Medical Association 226: 956–961. https://doi.org/10.2460/javma.2005.226.956 CrossRef Google Scholar PubMed

Anil, SS, Anil, L and Deen, J 2007 Factors associated with claw lesions in gestating sows. Journal of Swine Health and Production 15: 78–83Google Scholar

Auldist, D, Morrish, L, Eason, P and King, R 1998 The influ-ence of litter size on milk production of sows. Animal Science 67: 333–337. https://doi.org/10.1017/S1357729800010109 CrossRef Google Scholar

Barton, K 2017 MuMIn: Multi-Model Inference. R package version 1.40.0. https://CRAN.R-project.org/package=MuMIn Google Scholar

Bates, D, Maechler, M, Bolker, B and Walker, S 2015 Fitting linear mixed-effects models using [lme4]. Journal of Statistical Software 67: 1–48. https://doi.org/10.18637/jss.v067.i01 CrossRef Google Scholar

Baxter, EM, Lawrence, AB and Edwards, SA 2011 Alternative farrowing systems: design criteria for farrowing systems based on the biological needs of sows and piglets. Animal 5: 580–600. https://doi.org/10.1017/S1751731110002272 CrossRef Google Scholar PubMed

Baxter, EM, Rutherford, KMD, D’Eath, RB, Arnott, G, Turner, SP, Sandøe, P, Moustsen, VA, Thorup, F, Edwards, SA and Lawrence, AB 2013 The welfare implications of large litter size in the domestic pig II: management factors. Animal Welfare 22: 219–238. https://doi.org/10.7120/09627286.22.2.219 CrossRef Google Scholar

Blackshaw, JK and HalgelsØ, 1990 Getting-up and lying-down behaviours of loose-housed sows and social contacts between sows and piglets during day 1 and day 8 after parturition. Applied Animal Behaviour Science 25: 61–70. https://doi.org/10.1016/0168-1591(90)90070-T CrossRef Google Scholar

BMG 2012 Verordnung des Bundesministers für Gesundheit, mit der die 1. Tierhaltungsverordnung geändert wird, BGBl. II Nr 61/2012 vom 09.03.2012. https://www.ris.bka.gv.at/eli/bgbl/II/2012/61/20120309 Google Scholar

BMGF 2004 Verordnung der Bundesministerin für Gesundheit und Frauen über die Mindestanforderungen für die Haltung von Pferden und Pferdeartigen, Schweinen, Rindern, Schafen, Ziegen, Schalenwild, Lamas, Kaninchen, Hausgeflügel, Straußen und Nutzfischen (1. Tierhaltungsverordnung) vom 17.12.2004. https://www.ris.bka.gv.at /eli/bgbl/II/2004/485/20041217Google Scholar

BMWF 2012 Bundesgesetz, mit dem ein Tierversuchsgesetz 2012 erlassen wird sowie das Arzneimittelgesetz, das Biozid-Produkte-Gesetz, das Futtermittelgesetz 1999, das Gentechnikgesetz sowie das Tierschutzgesetz geändert werden (Tierversuchsrechtsänderungsgesetz– TVRÄG), BGBl. I Nr 114/2012 vom 28.12.2012. https://www.ris.bka.gv.at/eli/bgbl/I /2012/114/20121228Google Scholar

Bonde, M, Rousing, T, Badsberg, JH and Sørensen, JT 2004 Associations between lying-down behaviour problems and body condition, limb disorders and skin lesions of lactating sows housed in farrowing crates in commercial sow herds. Livestock Production Science 87: 179–187. https://doi.org/10.1016/j.livprod-sci.2003.08.005 CrossRef Google Scholar

Boyle, LA, Leonard, FC, Lynch, PB and Brophy, P 2000 Influence of housing system during gestation on the behaviour and welfare of gilts in farrowing crates. Animal Science 71: 561–570. https://doi.org/10.1017/S1357729800055302 CrossRef Google Scholar

Boyle, LA, Leonard, FC, Lynch, PB and Brophy, P 2002 Effect of gestation housing on behaviour and skin lesions of sows in far-rowing crates. Applied Animal Behaviour Science 76: 119–134. https://doi.org/10.1016/S0168-1591(01)00211-8 CrossRef Google Scholar

Cleveland-Nielsen, A, Bækbo, P and Ersbøll, AK 2004 Herd-related risk factors for decubital ulcers present at post-mortem meat-inspection of Danish sows. Preventative Veterinary Medicine 64: 113–122. https://doi.org/10.1016/j.prevetmed.2004.05.004 CrossRef Google Scholar PubMed

Cronin, GM, Smith, JA, Hodge, FM and Hemsworth, PH 1994 The behaviour of primiparous sows around farrowing in response to restraint and straw bedding. Applied Animal Behaviour Science 39: 269–280. https://doi.org/10.1016/0168-1591(94)90162-7 CrossRef Google Scholar

Curtis, SE, Hurst, RJ, Gonyou, HW, Jensen, AH and Muehling, AJ 1989 The physical space requirement of the sow. Journal of Animal Science 67: 1242–1248. https://doi.org/10.2527/jas1989.6751242x CrossRef Google Scholar

Dahl-Pedersen, K, Bonde, MK, Herskin, MS, Jensen, KH, Kaiser, M and Jensen, HE 2013 Pathogenesis and pathology of shoulder ulcerations in sows with special reference to peripheral nerves and behavioural responses to palpation. The Veterinary Journal 198: 666–671. https://doi.org/10.1016/j.tvjl.2013.09.059 CrossRef Google Scholar PubMed

Damm, BI, Lisborg, L, Vestergaard, KS and Vanicek, J 2003 Nest-building, behavioural disturbances and heart rate in farrowing sows kept in crates and Schmid pens. Livestock Production Science 80: 175–187. https://doi.org/10.1016/S0301-6226(02)00186-0 CrossRef Google Scholar

Damm, BI, Moustsen, V, Jørgensen, E, Pedersen, LJ, Heiskanen, T and Forkman, B 2006 Sow preferences for walls to lean against when lying down. Applied Animal Behaviour Science 99: 53–63. https://doi.org/10.1016/j.applanim.2005.09.014 CrossRef Google Scholar

Davies, PR, Morrow, WEM, Miller, DC and Deen, J 1996 Epidemiologic study of decubital ulcers in sows. Journal of American Veterinary Medical Association 208: 1058–1062Google Scholar PubMed

Davies, PR, Morrow, WEM, Rountree, WG and Miller, DC 1997 Epidemiologic evaluation of decubital ulcers in far-rowing sows. Journal of American Veterinary Medical Association 210: 1173–1178Google Scholar

Dewey, CE, Friendship, RM and Wilson, MR 1993 Clinical and postmortem examination of sows culled for lameness. The Canadian Veterinary Journal 34: 555–556Google Scholar PubMed

Dyck, GW and Swierstra, EE 1987 Causes of piglet death from birth to weaning. Canadian Journal of Animal Science 67: 543–547. https://doi.org/10.4141/cjas87-053 CrossRef Google Scholar

Edwards, S and Fraser, D 1997 Housing systems for farrowing and lactation. Pig Journal 39: 77–89Google Scholar

Edwards, SA and Lightfoot, AL 1986 The effect of floor type in farrowing pens on pig injury II. Leg and teat damage of sows. British Veterinary Journal 142: 441–445. https://doi.org/10.1016/0007-1935(86)90045-X CrossRef Google Scholar PubMed

EFSA 2007 Animal health and welfare aspects of different housing and husbandry systems for adult breeding boars, pregnant, far-rowing sows and unweaned piglets - Scientific Opinion of the Panel on Animal Health and Welfare. EFSA Journal 5: 572. https://doi.org/10.2903/j.efsa.2007.572 CrossRef Google Scholar

Fox, J and Weisberg, S 2011 An [R] Companion to Applied Regression. Sage: Thousand Oaks, CA, USAGoogle Scholar

Friendly, M 2017 vcdExtra: ‘vcd’ Extensions and Additions. R pack-age version 0.7-1. https://CRAN.R-project.org/package=vcdExtra Google Scholar

Hales, J, Moustsen, VA, Nielsen, MBF and Hansen, CF 2014 Higher pre-weaning mortality in free farrowing pens compared with farrowing crates in three commercial pig farms. Animal 8: 113–120. https://doi.org/10.1017/S1751731113001869 CrossRef Google Scholar

Hales, J, Moustsen, VA, Nielsen, MBF and Hansen, CF 2015 Temporary confinement of loose-housed hyperprolific sows reduces piglet mortality. Journal of Animal Science 93: 4079–4088. https://doi.org/10.2527/jas.2015-8973 CrossRef Google Scholar PubMed

Hansen, CF, Hales, J, Weber, PM, Edwards, SA and Moustsen, VA 2017 Confinement of sows 24 h before expected farrowing affects the performance of nest building behaviours but not progress of parturition. Applied Animal Behaviour Science 188: 1–8. https://doi.org/10.1016/j.applanim.2017.01.003 CrossRef Google Scholar

Harris, MJ and Gonyou, HW 1998 Increasing available space in a farrowing crate does not facilitate postural changes or maternal responses in gilts. Applied Animal Behaviour Science 59: 285–296. https://doi.org/10.1016/S0168-1591(98)00142-7 CrossRef Google Scholar

Hartig, F 2016 DHARMa: Residual Diagnostics for Hierarchical (Multi-Level / Mixed) Regression Models. R package version 0.1.4. https://cran.r-project.org/web/packages/DHARMa Google Scholar

Heidinger, B, Stinglmayr, J, Maschat, K, Oberer, M, Blumauer, E, Kuchling, S, Leeb, C, Hatzmann, E, Zentner, E, Hochfellner, L, Laubichler, C, Dolezal, M, Schwarz, L, Mösenbacher-Molterer, I, Vockenhuber, D and Baumgartner, J 2017 Evaluierung von neuen Abferkelbuchten mit Bewegungsmöglichkeit für die Sau, Bundesministerium für Land- und Forstwirtschaft, Umwelt und Wasserwirtschaft. https://www.dafne.at/dafne_plus_homepage/index.php?section=da fneplus&content=result&come_from=homepage&&project_id=3316. [Title translation: Evaluation of novel farrowing systems with the possibility for the sow to move]Google Scholar

Heinonen, M, Oravainen, J, Orro, T, Seppä-Lassila, L, Ala-Kurikka, E, Virolainen, J, Tast, A and Peltoniemi, OAT 2006 Lameness and fertility of sows and gilts in randomly selected loose-housed herds in Finland. Veterinary Record 159: 383. https://doi.org/10.1136/vr.159.12.383 CrossRef Google Scholar PubMed

Heinonen, M, Peltoniemi, O and Valros, A 2013 Impact of lameness and claw lesions in sows on welfare, health and production. Livestock Science 156: 2–9. https://doi.org/10.1016/j.livs-ci.2013.06.002 CrossRef Google Scholar

Herskin, MS, Bonde, MK, Jørgensen, E and Jensen, KH 2011 Decubital shoulder ulcers in sows: a review of classification, pain and welfare consequences. Animal 5: 757–766. https://doi.org/10.1017/S175173111000203X CrossRef Google Scholar PubMed

Holm, S 1979 A simple sequentially rejective multiple test procedure. Scandinavian Journal of Statistics 6: 65–70Google Scholar

Jarvis, S, Van der Vegt, BJ, Lawrence, AB, McLean, KA, Deans, LA, Chirnside, J and Calvert, SK 2001 The effect of parity and environmental restriction on behavioural and physio-logical responses of pre-parturient pigs. Applied Animal Behaviour Science 71: 203–216. https://doi.org/10.1016/S0168-1591(00)00183-0 CrossRef Google Scholar

Jensen, HE and Svendsen, O 2006 Skuldersår hos søer: Patogenese, graduering og komparative aspekter. Dansk Veterinærtidsskrift 89: 14–16. [Title translation: Shoulder ulcers in sows - pathogenesis, scoring and comparative aspects]Google Scholar

Kielland, C, Wisløff, H, Valheim, M, Fauske, AK, Reksen, O and Framstad, T 2018 Pre-weaning mortality in piglets in loose-housed herds: etiology and prevalence. Animal 12: 1950–1957. https://doi.org/10.1017/S1751731117003536 CrossRef Google Scholar

KilBride, A, Gillman, C, Ossent, P and Green, L 2009a Impact of flooring on the health and welfare of pigs. In Practice 31: 390–395. https://doi.org/10.1136/inpract.31.8.390 CrossRef Google Scholar

KilBride, AL, Gillman, CE and Green, LE 2009b A cross sectional study of the prevalence, risk factors and population attrib-utable fractions for limb and body lesions in lactating sows on commercial farms in England. BMC Veterinary Research 5: 30. https://doi.org/10.1186/1746-6148-5-30 CrossRef Google Scholar

Kilbride, AL, Mendl, M, Statham, P, Held, S, Harris, M, Cooper, S and Green, LE 2012 A cohort study of preweaning piglet mortality and farrowing accommodation on 112 commer-cial pig farms in England. Preventative Veterinary Medicine 104: 281–291. https://doi.org/10.1016/j.prevetmed.2011.11.011 CrossRef Google Scholar

Knage-Rasmussen, KM, Houe, H, Rousing, T and Sørensen, JT 2014 Herd- and sow-related risk factors for lameness in organic and conventional sow herds. Animal 8: 121–127. https://doi.org/10.1017/S1751731113001900 CrossRef Google Scholar PubMed

Lambertz, C, Petig, M, Elkmann, A and Gauly, M 2015 Confinement of sows for different periods during lactation: effects on behaviour and lesions of sows and performance of piglets. Animal 9: 1373–1378. https://doi.org/10.1017/S1751731115000889 CrossRef Google Scholar PubMed

Larsen, T, Kaiser, M and Herskin, MS 2015 Does the presence of shoulder ulcers affect the behaviour of sows? Research in Veterinary Science 98: 19–24. https://doi.org/10.1016/j.rvsc.2014.11.001 CrossRef Google Scholar PubMed

Lawrence, AB, Petherick, JC, McLean, KA, Deans, LA, Chirnside, J, Gaughan, A, Clutton, E and Terlouw, EMC 1994 The effect of environment on behaviour, plasma cortisol and prolactin in parturient sows. Applied Animal Behaviour Science 39: 313–330. https://doi.org/10.1016/0168-1591(94)90165-1 CrossRef Google Scholar

Leeb, C, Bernardi, F and Winckler, C 2010 Einführung und Monitoring von ‘BetriebsEntwicklungsPlänen (BEP) Tiergesundheit und Wohlbefinden’ in österreichischen Bioschweinebetrieben. Endbericht zum Forschungsprojekt 100188. Eigenverlag: Vienna, Austria. [Title trans-lation: Implementation and monitoring of farm development plans (BEP) animal health and welfare in Austrian organic pig farms]Google Scholar

Lefcheck, JS 2016 PiecewiseSEM: Piecewise structural equation modeling in R for ecology, evolution, and systematics. Methods in Ecology and Evolution 7: 573–579. https://doi.org/10.1111/2041-210X.12512 CrossRef Google Scholar

Lesnoff, M and Lancelot, R 2012 aod: Analysis of overdispersed data, R package version 1.3. http://cran.r-project.org/package=aod Google Scholar

Lewis, E, Boyle, LA, Lynch, PB, Brophy, P and O’Doherty, JV 2005 The effect of two teeth resection procedures on the welfare of piglets in farrowing crates, part 1. Applied Animal Behaviour Science 90: 233–249. https://doi.org/10.1016/j.appla-nim.2004.08.022 CrossRef Google Scholar

Marchant, J, Broom, D and Corning, S 2001 The influence of sow behaviour on piglet mortality due to crushing in an open far-rowing system. Animal Science 72: 19–28. https://doi.org/10.1017/S135772980005551X CrossRef Google Scholar

Marchant, JN, Rudd, AR, Mendl, MT, Broom, DM, Meredith, MJ, Corning, S and Simmins, PH 2000 Timing and causes of piglet mortality in alternative and conventional farrowing systems. The Veterinary Record 147: 209–214. https://doi.org/10.1136/vr.147.8.209 CrossRef Google Scholar PubMed

McGlone, JJ, Vines, B, Rudine, AC and DuBois, P 2004 The physical size of gestating sows. Journal of Animal Science 82: 2421–2427. https://doi.org/10.2527/2004.8282421x CrossRef Google Scholar PubMed

Meyer, D, Zeileis, A and Hornik, K 2006 The Strucplot Framework: Visualizing multi-way contingency tables with vcd. Journal of Statistical Software 17: 1–48. https://doi.org/10.18637/jss.v017.i03 CrossRef Google Scholar

Meyer, D, Zeileis, A, and Hornik, K 2017 vcd: Visualizing Categorical Data. R package version 1.4-4. https://cran.r-project.org /web/packages/vcd/Google Scholar

Milligan, BN, Fraser, D and Kramer, DL 2001 Birth weight variation in the domestic pig: effects on offspring survival, weight gain and suckling behaviour. Applied Animal Behaviour Science 73: 179–191. https://doi.org/10.1016/S0168-1591(01)00136-8 CrossRef Google Scholar PubMed

Moustsen, VA, Hales, J, Lahrmann, HP, Weber, PM and Hansen, CF 2013 Confinement of lactating sows in crates for 4 days after farrowing reduces piglet mortality. Animal 7: 648–654. https://doi.org/10.1017/S1751731112002170 CrossRef Google Scholar PubMed

Moustsen, VA, Lahrmann, HP and D’Eath, RB 2011 Relationship between size and age of modern hyper-prolific cross-bred sows. Livestock Science 141: 272–275. https://doi.org/10.1016/j.livsci.2011.06.008 CrossRef Google Scholar

Nicolaisen, T, Lühken, E, Volkmann, N, Rohn, K, Kemper, N and Fels, M 2019 The effect of sows’ and piglets’ behaviour on piglet crushing patterns in two different farrowing pen systems. Animals 9: 538. https://doi.org/10.3390/ani9080538 CrossRef Google Scholar PubMed

Norring, M, Valros, A, Munksgaard, L, Puumala, M, Kaustell, KO and Saloniemi, H 2006 The development of skin, claw and teat lesions in sows and piglets in farrowing crates with two con-crete flooring materials. Acta Agriculturae Scandinavica, Section A — Animal Science 56: 148–154. https://doi.org/10.1080/09064700701285065 Google Scholar

Olsson, A-C, Botermans, J and Englund, J-E 2018 Piglet mor-tality. A parallel comparison between loose-housed and tem-porarily confined farrowing sows in the same herd. Acta Agriculturae Scandinavica, Section A — Animal Science 68: 52–62. https://doi.org/10.1080/09064702.2018.1561934 Google Scholar

Pluym, L, Van Nuffel, A, Dewulf, J, Cools, A, Vangroenweghe, F, Van Hoorebeke, S and Maes, D 2011 Prevalence and risk factors of claw lesions and lameness in preg-nant sows in two types of group housing. Veterinarni Medicina (Praha) 56: 101–109. https://doi.org/10.17221/3159-VETMED CrossRef Google Scholar

R Core Team 2013 R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing: Vienna, AustriaGoogle Scholar

Rolandsdotter, E, Westin, R and Algers, B 2009 Maximum lying bout duration affects the occurrence of shoulder lesions in sows. Acta Agriculturae Scandinavica, Section A — Animal Science 51: 1–7. https://doi.org/10.1186/1751-0147-51-44 Google Scholar PubMed

Rosendahl, T and Nielsen, JP 2004 Risk factors for the development of decubital ulcers over the scapula in sows. Proceedings of the 18th IPVS Congress pp 717. 27 June-1 July 2004, Hamburg, GermanyGoogle Scholar

Rutherford, KMD, Baxter, EM, D’Eath, RB, Turner, SP, Arnott, G, Roehe, R, Ask, B, Sandøe, P, Moustsen, VA, Thorup, F, Edwards, SA, Berg, P and Lawrence, AB 2013 The welfare implications of large litter size in the domestic pig I: biological factors. Animal Welfare 22: 199–218. https://doi.org/10.7120/09627286.22.2.199 CrossRef Google Scholar

Salak-Johnson, JL, Niekamp, SR, Rodriguez-Zas, SL, Ellis, M and Curtis, SE 2007 Space allowance for dry, pregnant sows in pens: Body condition, skin lesions, and performance 1. Journal of Animal Science 85: 1758–1769. https://doi.org/10.2527/jas.2006-510 CrossRef Google Scholar

Sarkar, D 2008 Lattice: Multivariate Data Visualization with R. Springer: New York, USA. https://doi.org/10.1007/978-0-387-75969-2 CrossRef Google Scholar

Troxler, J and Weber, R 1988 Anwendung ethologischer Erkenntnisse bei der Prüfung von Stalleinrichtungen für Schweine. Aktuelle Arbeiten zur artgemäßen Tierhaltung pp 142–149. 17-19 November 1988, Freiburg/Breisgau, Germany. KBTL: Darmstadt, Germany. [Title translation: Application of ethological findings in the testing of housing facilities for pigs]Google Scholar

Venables, WN and Ripley, BD 2002 Modern Applied Statistics with S. Springer: New York, USA. https://doi.org/10.1007/978-0-387-21706-2 CrossRef Google Scholar

Verhovsek, D, Troxler, J and Baumgartner, J 2007 Peripartal behaviour and teat lesions of sows in farrowing crates and in a loose-housing system. Animal Welfare 16: 273–276CrossRef Google Scholar

Weber, R, Keil, N, Fehr, M and Horat, R 2007 Piglet mortality on farms using farrowing systems with or without crates. Animal Welfare 16: 277–279CrossRef Google Scholar

Welfare Quality® 2009 Assessment protocol for pigs. Welfare Quality® Consortium: Lelystad, The NetherlandsGoogle Scholar

Wickham, H 2009 ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag: New York, USA. https://doi.org/10.1007/978-0-387-98141-3 CrossRef Google Scholar

Zurbrigg, K 2006 Sow shoulder lesions: Risk factors and treat-ment effects on an Ontario farm. Journal of Animal Science 84: 2509–2514. https://doi.org/10.2527/jas.2005-713 CrossRef Google Scholar

Zurbrigg, K and Blackwell, T 2006 Injuries, lameness, and cleanliness of sows in four group-housing gestation facilities in Ontario. Journal of Swine Health and Production 14: 202–206Google Scholar