Skip to main content Accessibility help

Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions

  • G. A. Carroll (a1), L. A. Boyle (a2), D. L. Teixeira (a2), N. van Staaveren (a2) (a3), A. Hanlon (a3) and N. E. O’Connell (a1)...


There is increasing interest in developing abattoir-based measures to assist in determining the welfare status of pigs. The primary aim of this study was to determine the most appropriate place on the slaughter line to conduct assessments of welfare-related lesions, namely apparent aggression-related skin lesions (hereafter referred to as ‘skin lesions’), loin bruising and apparent tail biting damage. The study also lent itself to an assessment of the prevalence of these lesions, and the extent to which they were linked with production variables. Finishing pigs processed at two abattoirs on the Island of Ireland (n=1950 in abattoir A, and n=1939 in abattoir B) were used. Data were collected over 6 days in each abattoir in July 2014. Lesion scoring took place at two points on the slaughter line: (1) at exsanguination (slaughter stage 1 (SS1)), and (2) following scalding and dehairing of carcasses (slaughter stage 2 (SS2)). At both points, each carcass was assigned a skin and tail lesion score ranging from 0 (lesion absent) to 3 or 4 (severe lesions), respectively. Loin bruising was recorded as present or absent. Differences in the percentage of pigs with observable lesions of each type were compared between SS1 and SS2 using McNemar/McNemar-Bowker tests. The associations between each lesion type, and both cold carcass weight and condemnations, were examined at batch level using Pearson’s correlations. Batch was defined as the group of animals with a particular farm identification code on a given day. The overall percentage of pigs with a visible skin lesion (i.e. score>0) decreased between SS1 and SS2 (P<0.001). However, the percentage of pigs with a severe skin lesion increased numerically from SS1 to SS2. The percentage of pigs with a visible tail lesion and with loin bruising also increased between SS1 and SS2 (P<0.001). There was a positive correlation between the percentage of carcasses that were partially condemned, and the percentage of pigs with skin lesions, tail lesions and loin bruising (P<0.05). In addition, as the batch-level frequency of each lesion type increased, average cold carcass weight decreased (P<0.001). These findings suggest that severe skin lesions, tail lesions and loin bruising are more visible on pig carcasses after they have been scalded and dehaired, and that this is when abattoir-based lesion scoring should take place. The high prevalence of all three lesion types, and the links with economically important production parameters, suggests that more research into identifying key risk factors is warranted.


Corresponding author



Hide All
Aaslyng, MD, Brandt, P, Blaabjerg, L and Støier, S 2013. Assessment and incidence of skin damage in slaughter pigs. Proceedings of the 59th International Congress of Meat Science and Technology, 13–23 August, Izmir, Turkey.
BPEX 2010. Key industry statistics, pig performance data and details of knowledge transfer, research and development activity. Retrieved March 31, 2015, from
Dalmau, A, Temple, D, Rodriguez, P, Llonch, P and Velarde, A 2009. Application of the Welfare Quality (R) protocol at pig slaughterhouses. Animal Welfare 18, 497505.
D’Eath, RB 2012. Repeated locomotion scoring of a sow herd to measure lameness: consistency over time, the effect of sow characteristics and inter-observer reliability. Animal Welfare 21, 219231.
Department of Agriculture and Rural Development 2013. The agricultural census in Northern Ireland. Retrieved January 12, 2015, from
Edwards, DS, Johnston, AM and Mead, GC 1997. Meat inspection: an overview of present practices and future trends. Veterinary Journal 154, 135147.
European Food Safety Authority 2012. Scientific opinion on the use of animal-based measures to assess welfare in pigs. The EFSA Journal 10, 2512.
Garcia-Diaz, J and Coelho, AC 2014. Causes and factors related to pig carcass condemnation. Veterinarni Medicina 59, 194201.
Guardia, MD, Estany, J, Balasch, S, Oliver, MA, Gispert, M and Diestre, A 2009. Risk assessment of skin damage due to pre-slaughter conditions and RYR1 gene in pigs. Meat Science 81, 745751.
Harley, S, Boyle, LA, O’Connell, NE, More, SJ, Teixeira, DL and Hanlon, A 2014. Docking the value of pigmeat? Prevalence and financial implications of welfare lesions in Irish slaughter pigs. Animal Welfare 23, 275285.
Harley, S, More, S, Boyle, L, O’Connell, NE and Hanlon, A 2012a. Good animal welfare makes economic sense: potential of pig abattoir meat inspection as a welfare surveillance tool. Irish Veterinary Journal 65, 112.
Harley, S, More, SJ, O’Connell, NE, Hanlon, A, Teixeira, D and Boyle, L 2012b. Evaluating the prevalence of tail biting and carcase condemnations in slaughter pigs in the Republic and Northern Ireland, and the potential of abattoir meat inspection as a welfare surveillance tool. Veterinary Record 171, 621621.
Huey, R 1996. Incidence, location and interrelationships between the sites of abscesses recorded in pigs at a bacon factory in Northern Ireland. Veterinary Record 138, 511514.
Hunter, EJ, Jones, TA, Guise, HJ, Penny, RHC and Hoste, S 1999. Tail biting in pigs 1: the prevalence at six UK abattoirs and the relationship of tail biting with docking, sex and other carcass damage. Pig Journal 43, 1832.
Kritas, SK and Morrison, RB 2007. Relationships between tail biting in pigs and disease lesions and condemnations at slaughter. Veterinary Record 160, 149152.
March, S, Brinkmann, J and Winkler, C 2007. Effect of training on the inter-observer reliability of lameness scoring in dairy cattle. Animal Welfare 16, 131133.
Marques, BMFPP, Bernardi, ML, Coelho, CF, Almeida, M, Morales, OE, Mores, TJ, Borowski, SM and DESN, Barcellos 2012. Influence of tail biting on weight gain, lesions and condemnations at slaughter of finishing pigs. Pesquisa Veterinaria Brasileira 32, 967974.
National Statistics Service 2014. Sample size calculator. Retrieved December 9, 2014, from
Nielsen, SS, Michelsen, AM, Jensen, HE, Barington, K, Opstrup, KV and Agger, JF 2014. The apparent prevalence of skin lesions suspected to be human-inflicted in Danish finishing pigs at slaughter. Preventive Veterinary Medicine 117, 200206.
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 pregnant sows in two types of group housing. Veterinarni Medicina 56, 101109.
Reimert, I, Rodenburg, TB, Ursinus, WW, Kemp, B and Bolhuis, JE 2014. Selection based on indirect genetic effects for growth, environmental enrichment and coping style affect the immune status of pigs. PLoS One 9, e108700.
Robin, S, Courderot-Masuyer, C, Tauzin, H, Harbon, S, Chavagnac-Bonneville, M, Cadars, B, Jourdan, E, Trompezinski, S and Humbert, P 2015. Use of a model of a blood-induced bruise for the evaluation of formulations on bruising. Journal of Cosmetics, Dermatological Sciences and Applications 5, 714.
Ruis, MAW, te Brake, JHA, Engel, B, Buist, WG, Blokhuis, HJ and Koolhaas, M 2002. Implications of coping characteristics and social status for welfare and production of paired growing gilts. Applied Animal Behaviour Science 75, 207231.
Sanchez-Vazquez, MJ, Strachan, WD, Armstrong, D, Nielen, M and Gunn, GJ 2011. The British pig health schemes: integrated systems for large-scale pig abattoir lesion monitoring. Veterinary Record 169, 413.
Stärk, KDC, Alonso, S, Dadios, N, Dupuy, C, Ellerbroek, L, Georgiev, M, Hardstaff, J, Huneau-Salauen, A, Laugier, C, Mateus, A, Nigsch, A, Afonso, A and Lindberg, A 2014. Strengths and weaknesses of meat inspection as a contribution to animal health and welfare surveillance. Food Control 39, 154162.
Taylor, NR, Main, DCJ, Mendl, M and Edwards, SA 2010. Tail-biting: a new perspective. Veterinary Journal 186, 137147.
Teagasc 2011. Irish pig herd survey. Retrieved January 12, 2015, from
Teixeira, DL and Boyle, LA 2014. A comparison of the impact of behaviours performed by entire male and female pigs prior to slaughter on skin lesion scores of the carcass. Livestock Science 170, 142149.
Valros, A, Ahlstrom, S, Rintala, H, Hakkinen, T and Saloniemi, H 2004. The prevalence of tail damage in slaughter pigs in Finland and associations to carcass condemnations. Acta Agriculturae Scandinavica Section A-Animal Science 54, 213219.
Valros, A, Munsterhjelm, C, Puolanne, E, Ruusunen, M, Heinonen, M, Peltoniemi, OAT and Poso, AR 2013. Physiological indicators of stress and meat and carcass characteristics in tail bitten slaughter pigs. Acta Veterinaria Scandinavica 55, 75.
Velarde, A, Dalmau, A, Fàbrega, E and Manteca, X 2005. Health and welfare management of pigs based on slaughterline records. 56th Annual Meeting of the European Association for Animal Production, Uppsala, Sweden.
Wallgren, P and Lindahl, E 1996. The influence of tail biting on performance of fattening pigs. Acta Veterinaria Scandinavica 37, 453460.
Warriss, P, Brown, S, Gade, P, Santos, C, Costa, L, Lambooij, E and Geers, R 1998. An analysis of data relating to pig carcass quality and indices of stress collected in the European Union. Meat Science 49, 137144.


Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions

  • G. A. Carroll (a1), L. A. Boyle (a2), D. L. Teixeira (a2), N. van Staaveren (a2) (a3), A. Hanlon (a3) and N. E. O’Connell (a1)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed