Tag Archives: pain

The perception of pain by pigs and implications for farm and veterinary practice

The perception of pain by pigs and implications for farm and veterinary practice. Edwards, S., 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 13-17.

Abstract

“Freedom from pain, injury and disease” is one of the fundamental aspects of good animal welfare. However, in commercial pig production there are a number of situations where animals may experience pain. This may result from procedures carried out deliberately for management purposes, or from spontaneous health disorders. In order to make decisions on the ethical justification of procedures and the provision of pain alleviation by appropriate anaesthesia and analgesia, it is necessary to assess the intensity and duration of pain experienced by the animals. A number of behavioural, physiological and molecular methods now exist for such assessment but, since pain is a subjective experience which the individual may express in different ways, interpreting these measures can be a challenge. Better methods are required for the practical on-farm assessment of pain and the provision of analgesia when this occurs.

Paper available in the proceedings.

Traumatic neuroma development in tail docked piglets is not associated with long-term changes in spinal nociceptive processing

Traumatic neuroma development in tail docked piglets is not associated with long-term changes in spinal nociceptive processing. By Sandercock, D., S. Smith, J. Coe, P. Di Giminiani, S. Edwards, 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 611.

Abstract

Introduction: Concerns exist over the long term consequences for tail stump pain experienced by piglets after docking, especially in relation to traumatic neuroma development in caudal nerves after docking injury. Neuroma formation may cause detrimental sensory changes in the tail due to altered axonal excitability leading to abnormal sensation or pain.

Aims: To characterize pig tail histopathology at time intervals up to 16 weeks after tail docking and to measure expression of key neuropeptides in caudal dorsal root ganglia and spinal cord neurons associated with (i) peripheral nerve regeneration; activating transcription factor-3 (ATF3), (ii) inflammatory pain; Calcitonin gene-related peptide (CGRP) and (iii) the maintenance of chronic pain; N-methyl D-aspartate (NMDA) ionotropic glutamate receptor subtype 2B (GRIN2B) at the same time points after tail docking injury.

Materials and Methods: Thirty-two female piglets (Landrace/Large White x synthetic sireline) were used (16 docked/16 sham-docked). Piglets were tail docked (amputation of approx. 2/3 of the tail) on post-natal day 3 using a gas hot docking iron. Equivalent sham-docked piglets served as intact controls. Pigs were euthanized by barbiturate overdose 1, 4, 8 and 16 weeks after sham/tail docking. Tail stumps (2 cm) were collected post-mortem for histopathological assessment. Caudal dorsal root ganglia (Ca1-Ca4+) and associated spinal cord were collected for gene expression analysis by real-time quantitative PCR of mRNA.

Results: Non-specific epidermal and dermal changes associated with healing were observed after tail docking. Mild inflammation, ulceration and oedema were present at 1 week. Traumatic neuroma development was a consistent feature from 4 weeks after tail docking. Neuroma axonal dispersion in the tail stump was on-going 16 weeks after tail docking. ATF-3 mRNA was significantly upregulated in caudal DRGs up to 8 weeks after tail docking, but did not differ at 16 weeks compared with sham controls. Both CGRP and GRIN2B mRNA expression was significantly upregulated 1 week after tail docking in caudal spinal cord neurons but were not significantly different from sham-docked pigs thereafter.

Conclusion: Histopathological lesions that occur shortly after tail docking (beyond 1 week) are not likely to induce or maintain pain. The effects of tail docking on peripheral nerve axonal proliferation and dispersion are relatively short-lived and, although still present, are attenuated by 16 weeks after tail docking injury. Changes in peripheral and spinal nociceptive processing associated with possible inflammatory and chronic pain appear to resolve by 4 weeks after tail docking injury.

Poster Sandercock IPVS

Temporal changes in mechanical nociceptive thresholds in juvenile pigs subjected to surgical tail amputation: a model of injury induced by tail biting

Temporal changes in mechanical nociceptive thresholds in juvenile pigs subjected to surgical tail amputation: a model of injury induced by tail biting. By Di Giminiani, P., E. Malcolm, M. Leach, M. Herskin, D. Sandercock, S. Edwards, 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 649.

Abstract

Introduction: Tail biting is a global welfare problem in the pig industry leading to significant tail injury and potential carcass rejection. The temporal effects of such injuries and subsequent healing are presently unknown, although limb amputation in humans can lead to abnormal neural activity and decreased nociceptive thresholds. In order to evaluate potential sensitisation following tail damage, we created a model by surgical amputation of tails, and assessed mechanical nociceptive thresholds.

Materials and Methods: Surgical tail resection was performed to assess the influence of age, extent of tail amputated and time since amputation on thresholds of mechanical nociception. To evaluate the effect of age at the time of injury, female pigs underwent surgery at 9 weeks (±3 days ‘weaner’) (n=19) or 17 weeks (±3 days ‘finisher’) (n=43). The effect of time after amputation was evaluated on 24 pigs at 8 weeks, and 38 pigs at 16 weeks after surgery. The effect of the extent of tail amputated was assessed by assigning the pigs to 3 treatments (‘Intact’: sham-amputation; ‘short tail’: 2/3 of tail removed; ‘long tail’: 1/3 of tail removed). A Pressure Application Measurement device was used to record mechanical nociceptive thresholds (tail flick or tail clamp withdrawal responses). Within a single session, three stimuli were applied to a skin area proximal to the site of amputation, 3 days pre-surgery, 1 week and either 8 or 16 weeks post-amputation.

Results: Across the two amputation ages, results indicated that tail amputation induced a significant reduction (P<0.05) in mechanical nociceptive thresholds in short and long tails one week after surgery. The same treatment effect was observed at 16 weeks after amputation performed at 9 weeks of age (P<0.05). For surgeries performed at 17 weeks of age, thresholds tended to be lower in short compared to intact tails (P=0.081) and significantly lower (P<0.05) in long tail pigs 8 weeks after amputation. No significant difference was observed at 16 weeks following surgeries performed at 17 weeks of age.

Conclusion: These results show that surgical amputation of pig tails leads to decreased cutaneous mechanical nociceptive thresholds in the skin area proximal to the site of injury. Results indicated that severe tail injury occurring in the weaner period may be associated with sensitisation up to 16 weeks following the injury. In contrast, injuries occurring in the finishing period appeared to be associated with shorter lasting mechanical sensitisation, resolving within 16 weeks.

Poster Di Giminiani IPVS

 

Application of a handheld Pressure Application Measurement device for the characterisation of mechanical nociceptive thresholds in intact pig tails

Application of a handheld Pressure Application Measurement device for the characterisation of mechanical nociceptive thresholds in intact pig tails. By Pierpaolo Di Giminiani, Dale A. Sandercock, Emma M. Malcolm, Matthew C. Leach, Mette S. Herskin and Sandra A. Edwards. 2016. Physiology & Behavior 165: 119–126.

Highlights

• Mechanical nociceptive thresholds were quantified for the first time in pig tails.
• The PAM device allowed determining anatomical and age-specific thresholds in pigs.
• A platform for the assessment of painful conditions in pigs is proposed.

Abstract

The assessment of nociceptive thresholds is employed in animals and humans to evaluate changes in sensitivity potentially arising from tissue damage. Its application on the intact pig tail might represent a suitable method to assess changes in nociceptive thresholds arising from tail injury, such as tail docking or tail biting. The Pressure Application Measurement (PAM) device is used here for the first time on the tail of pigs to determine the reliability of the methods and to provide novel data on mechanical nociceptive thresholds (MNT) associated with four different age groups (9, 17, 24 and 32 weeks) and with proximity of the target region to the body of the animal. We recorded an overall acceptable level of intra-individual reliability, with mean values of CV ranging between 30.1 and 32.6%. Across all age groups, the first single measurement of MNT recorded at region 1 (proximal) was significantly higher (P b 0.05) than the following two. This was not observed at tail regions 2 and 3 (more distal). Age had a significant effect (P b 0.05) on the mean thresholds of nociception with increasing age corresponding to higher thresholds. Furthermore, a significant effect of proximity of tail region to the body was observed (P b 0.05), with MNT being higher in the proximal tail region in pigs of 9, 17 and 24 weeks of age.
There was also a significant positive correlation (P b 0.05) between mechanical nociceptive thresholds and age/body size of the animals.
To the best of our knowledge, no other investigation of tail nociceptive thresholds has been performed with the PAM device or alternative methods to obtain mechanical nociceptive thresholds in intact tails of pigs of different age/body size. The reliability of the data obtained with the PAM device support its use in the measurement of mechanical nociceptive threshold in pig tails. This methodological approach is possibly suitable for assessing changes in tail stump MNTs after tail injury caused by tail docking and biting.

Reducing mutilations in the European Union

A study on reducing the number of mutilations on animals within the European Union
By Sanne van Zanen (Student Wageningen University, email: sanne . vanzanen @ wur . nl)
Commissioned by the Ministry of Economic Affairs, the Netherlands

Abstract

This study has gathered information about the possibilities to reduce the number of mutilations throughout the European Union. It has focused on surgical castration of male pigs, tail docking of pigs and beak trimming of laying hens. According to literature, these mutilations have received most attention in the European Union. Furthermore, in most of the European member states these mutilations are frequently carried out. The study is performed by a graduate student of Wageningen University and commissioned by the Ministry of Economic Affairs. The conclusions of this study do not necessary reflect the official opinion of the Ministry of Economic Affairs.

This study started off with a desk research that sketched the concept of animal welfare across the European Union. A framework of factors that influence the importance attached to animal welfare resulted from this research and was used to clarify the results of the two additional studies within the broad concept of animal welfare across the European Union. The two additional studies that were performed are a literature study and a questionnaire. The literature study has focused on retrieving in-depth information on the current situation of the member states regarding the three mutilations. The questionnaire was set up to get insights into which actions have the greatest chance of success and what are the biggest obstacles in reducing the number of mutilations in animals. The questionnaire was spread, by means of an introducing email, to scientific researchers, veterinarians, policy
makers/officers, NGO’s, employees in a slaughterhouse, farmers and students across the European Union. In total 130 respondents filled out questions about at least one of the three mutilations across 16 member states (Cyprus, Bulgaria, Greece, Luxembourg, Latvia, Czech Republic, Hungary, Estonia, Lithuania, Malta, Romania and Slovenia have not taken part in the questionnaire).

United Kingdom, Ireland, Spain and Portugal nearly raise all their pigs as entire boars. In contrast to these countries, surgical castration of male pigs is the most desired option for the Italian pig market (and parts of the Spanish and Portuguese pig production). This is due to the restrictions imposed by the Parma ham industry (slaughtering pigs at
heavy weights). Consequently, the restrictions imposed by the Parma Industry and the sensitivity for boar taint are the biggest obstacles for reducing surgical castration for the Mediterranean countries. The Eastern European and Central European region do also nearly all surgically castrate their pigs and consider the restrictions imposed by the
Parma Industry and or boar taint sensitivity as an obstacle. The Northern European and Scandinavian regions have already made some efforts on reducing the number of practices by means of non-legislative initiatives. However, the biggest problem for realizing a complete stop of these regions and an additional problem of the Central and Eastern European regions is related to the absence of (inter)national acceptance of non-castrated pigs or immunocastrated pigs, which is crucial for these exporting countries. Consequently, on-line detection methods on the slaughter line of boar taint is of high importance. A legislative approach by the national government is seen by each geography region as the most successful factor for reducing the number of surgical castrated pigs, except central European region (remains unknown).

Tail docking of pigs is forbidden by national law in Sweden, Finland and Lithuania. The remaining Northern European countries do carry out this procedure on pigs, but an increasing number of legislative and non-legislative initiatives within this region show the urgency of phasing out this mutilation. The other European regions raise also pigs with docked tails, but no active initiatives could be found that aim for a reduction of this procedure. These regions consider a lack of political interest and or consumer willingness to pay for more animal friendly products as obstacles for realizing a reduction. Moreover, each region thinks of the following animal production related factors: large stocking densities of groups of pigs, floor type of housing system used and absence and or insufficient enrichment as likely being a restriction in order to realize a reduction of tail docking. A legislation approach by the national government is the most successful factor for realizing a reduction. The Central European region is an exception, because they consider a wholesale price increase by national retailers as most successful.

Beak trimming of laying hens, is already forbidding in Sweden, Finland, Austria and Denmark either by means of national legislation or as a voluntary ban by the poultry sector. Legislative and non-legislative initiatives aim for a stop in the near future or a reduction of beak trimming within the Northern European region. The other regions do
not show a sense of urgency for reducing beak trimming of laying hens. A lack of willingness to pay of consumers and political interest are seen as obstacles for reducing beak trimming within these regions. Furthermore, it seems that the husbandry systems of these regions are not ready yet to raise hens with intact beaks, because large stocking densities, breed and the housing system used are seen as the most frequent additional obstacles. A legislation approach by the national government is the factor with the greatest chance of realizing a reduction of beak trimming for most of the regions (Northern- and Eastern European regions remain unknown). The central European region considers the influence of large multinationals as most successful. Furthermore, the questionnaire results of the Eastern European region could not be used, it is expected that this region is not ready (yet) to reduce the number of beak trimming procedures.

See also Initiatives to reduce mutilations in EU livestock production. By Spoolder, H.A.M.; Schone, Maria; Bracke, M.B.M. 2016. Report 940. Wageningen Livestock Research, Wageningen.

Docking a piglet's tail using cautery (hot iron)

Executive summary

Which of the European member states have the potential to join the four front-runners?

The European member states that have the potential to become a coalition partner of the Netherlands, Germany, Denmark and Sweden to reduce surgical castration of male pigs, tail docking of pigs and beak trimming of laying hens within the European Union.

Thesis
S.E.J. van Zanen
March 11, 2016
Adaptation Physiology Group
Wageningen University & Ministry of Economic Affairs

In order to get animal welfare higher on the European agenda The Netherlands, Germany and Denmark reached an agreement on several animal welfare related mutilations in 2014. Sweden joined the trilateral agreement in 2015. It is expected that by means of a joint European approach the biggest win for improving animal welfare can be reached within the European context. The main research question in this study is: which European member states have the potential to become a coalition partner of the Netherlands, Germany, Denmark and Sweden in order to reduce surgical castration procedures in male pigs, tail docking procedures in pigs and beak trimming procedures
in laying hens? Other research questions are about the influence of the individual member states in the European Union and the key success factors and the biggest obstacles in realizing a reduction of each of the three mutilations within several geographic regions.
This study starts with a desk research that sketches the concept of animal welfare across the European Union. The result is a framework of factors that influences the importance attached to animal welfare and is used to explain the results of the following two studies within the broad concept of animal welfare across the European Union. A second desk research focuses on retrieving in-depth information on the current situation of the member states regarding the three mutilations. Thirdly, a questionnaire was set up to get insights into which actions have the greatest chance of success and what are the biggest obstacles in reducing the number of mutilations in animals. The questionnaire was spread, by means of an introducing email, to scientific researchers, veterinarians, policy makers/officers, NGO’s, employees in a slaughterhouse, farmers and students across the European Union. In total 130 respondents filled out questions about at least one of the three mutilations across 16 member states (Cyprus, Bulgaria, Greece, Luxembourg, Latvia, Czech Republic, Hungary, Estonia, Lithuania, Malta, Romania and Slovenia have not taken part in the questionnaire). Germany, France, Italy and the United Kingdom are the most influential member states within the European Union. Furthermore, these member states, together with the Netherlands, Denmark, Spain and Poland are the biggest egg and pig producing states and or the greatest exporting countries of pork meat.
A legislative approach by the national government is seen by each geographical region as the most successful factor for reducing the number of surgical castrated pigs, except the central European region (remains unknown).
The majority of the pigs raised in the United Kingdom, Ireland, Spain and Portugal are entire boars. In contrast to these member states, the restrictions imposed by the Parma ham industry force the Italian pig market (and small parts of the Spanish and Portuguese pig production) to slaughter their pigs at heavy weights, which makes surgical castration the most desired option. Consequently, the restrictions imposed by the Parma Industry and the sensitivity for boar taint are the biggest obstacles for reducing surgical castration for the Mediterranean region. The Eastern European and Central European region do also nearly all surgically castrate their pigs and consider the restrictions imposed by the Parma Industry and or boar taint sensitivity as an obstacle(s). The Northern European and Scandinavian regions have already made some efforts on reducing the number of surgical castration practices by means of non-legislative initiatives. However, the biggest problem for realizing a complete stop in these regions (and an additional problem of the Central and Eastern European regions) is related to the absence of (inter)national acceptance of non-castrated pigs or immunocastrated pigs, which is crucial for these exporting countries. Consequently, on-line detection methods on the slaughter line of boar taint is of high importance. It is suggested that the United Kingdom has the highest potential to be a coalition partner of the Netherlands, Germany, Denmark and Sweden in order to reduce the number of surgical castrated pigs within the European Union.
The majority of the geographic regions consider a legislation approach by the national government as the most successful factor for realizing a reduction of tail docking of pigs. The Central European region is an exception, because they think of a wholesale price increase by retailers as most successfull. Tail docking of pigs is forbidden by national law in Sweden, Finland and Lithuania. The Northern European region does carry out this procedure on pigs, but an increasing number of legislative and nonlegislative initiatives within this region show the urgency of phasing out this mutilation. The other European regions raise also pigs with docked tails, but no active initiatives could be found that aim for a reduction of this procedure. These regions consider a lack of political interest and or consumer willingness to pay for more animal friendly products as obstacles for realizing a reduction. Moreover, each region considers large stocking densities of groups of pigs, floor type of housing system used and absence and or insufficient enrichment as animal-production based obstacles for realizing a reduction of tail docking. It is expected that Finland has the highest potential to be a coalition partner of the Netherlands, Germany, Denmark and Sweden in order to reduce the number of tail docking procedures in pigs within the European Union.
The Mediterranean region considers a legislative approach by the national government as the factor with the greatest chance of success in realizing a reduction of beak trimming procedures (Northern- and Eastern European regions remain unknown). The Central European region considers the influence of large multinationals as most successful. Furthermore, the questionnaire results of the Eastern European region could not be used, it is expected that this region is not ready (yet) to reduce the number of beak trimming procedures. Beak trimming of laying hens is already forbidding in Sweden, Finland, Austria and Denmark either by means of national legislation or as a voluntary ban by the poultry sector. Legislative and non-legislative initiatives aim for a stop in the near future or a reduction of beak trimming procedures within the Northern European region. The other regions do not show a sense for urgency of reducing beak trimming of laying hens. A lack of willingness to pay of consumers and political interest are seen as obstacles for reducing beak trimming within these regions. Furthermore, the husbandry systems of these regions are not ready yet to raise hens with intact beaks, because large stocking densities, breed and the housing system used are seen as the most frequent additional obstacles. Austria and Finland are suggested to have the highest potential to be coalition partners of the Netherlands, Germany, Denmark and Sweden in order to reduce the number of beak trimming procedures in laying hens within the European Union.

Effects of tail docking and docking length on neuroanatomical changes in healed tail tips of pigs

Effects of tail docking and docking length on neuroanatomical changes in healed tail tips of pigs
By M. S. Herskin, K. Thodberg and H. E. Jensen. 2015. Animal 9: 677-681.

Abstract

In pig production, piglets are tail docked at birth in order to prevent tail biting later in life. In order to examine the effects of tail docking and docking length on the formation of neuromas, we used 65 pigs and the following four treatments: intact tails (n=18); leaving 75% (n=17); leaving 50% (n=19); or leaving 25% (n=11) of the tail length on the pigs. The piglets were docked between day 2 and 4 after birth using a gas-heated apparatus, and were kept under conventional conditions until slaughter at 22 weeks of age, where tails were removed and examined macroscopically and histologically. The tail lengths and diameters differed at slaughter (lengths: 30.6±0.6; 24.9±0.4; 19.8±0.6; 8.7±0.6 cm; P<0.001; tail diameter: 0.5±0.03; 0.8±0.02; 1.0±0.03; 1.4±0.04 cm; P<0.001, respectively). Docking resulted in a higher proportion of tails with neuromas (64 v. 0%; P<0.001), number of neuromas per tail (1.0±0.2 v. 0; P<0.001) and size of neuromas (1023±592 v. 0 μm; P<0.001). The results show that tail docking piglets using hot-iron cautery causes formation of neuromas in the outermost part of the tail tip. The presence of neuromas might lead to altered nociceptive thresholds, which need to be confirmed in future studies.

Influence of tail docking, with or without a cold analgesic spray, on behaviour, performance and physiology of piglets

Influence of tail docking, with or without a cold analgesic spray, on behaviour, performance and physiology of piglets
By Armelle Prunier, Gaëlle Bataille, Marie-Christine Meunier-Salaün, Aline Bregeon, Y. Rugraff. 2001. Journées Rech. Porcine en France, 33, 313-318. (Article in French).

Abstract

Tail docking performed in order to avoid tail biting in fattening pigs is criticized. In order to assess its short term consequences, two experiments were realized. The first one performed on 160 piglets from 32 litters was focussed on the behavioural consequences and the growth performance. The aim of the second one was to determine the effects of tail docking on the adrenal (plasma cortisol and ACTH) and sympathetic (measurement of glucose and lactate released from catecholamine-induced mobilization of glycogen) axes in 20 piglets from 7 litters which were catheterized at birth. In the first experiment, there were 5 treatments: tail docking, tail docking + a cold analgesic spray, control handling, control handling + spray, no handling. In the second experiment, the same treatments were run, except the fourth one. Treatments were applied the day after birth and tail was docked with an iron docking (cautery). During treatment, tail docking caused more movements (legs and/or body) and howls (P < 0.05). During the 20 s following treatment, docked piglets demonstrated more tail jamming and wagging (P < 0.05). Both types of docking consequences were attenuated when the cold spray was used. During the following 12 hours, time spent by the piglets to rest or to be active at the sow udder was similar in the 5 groups. Growth rate during the first week of life and the occurrence of injuries at the tail did not differ between groups (P > 0.1). Tail docking with or without the cold spray had no marked effects on the patterns of plasma cortisol, ACTH, glucose and lactate. In conclusion, tail docking causes probably pain of moderate amplitude.

Impact of tail docking on behaviour of suckling piglets

Impact of tail docking on behaviour of suckling piglets
by Céline Tallet, Marine Rakotomahandry, Sabine Herlemont, Armelle Prunier, 2016. Journées Recherche Porcine, 48, 235-236 (Article in French).

Abstract

Tail docking is still applied in Europe to prevent tail biting, despite its evident negative impact on pig welfare. We aimed at characterising consequences of tail docking on suckling piglets. We compared 48 piglets with tail docked (C) to 50 undocked piglets submitted to a non-painful simulation of docking (S). Their behavioural reaction during docking and for 20 s following the process was observed: vocalisations, tail posture and movements. Observations were repeated on C animals and on 48 other animals left intact from birth (I), 4 h after the docking process, 3 days after and once a week, in addition giving a score to the state of the tail. Fifteen days after birth, their reaction to a motionless seated human was observed. The C piglets vocalised more and louder during the docking process than S piglets (P < 0.05). For the 20 s after docking, their tail remained immobile longer (P < 0.05). The tail was also more immobile during the whole suckling period (P < 0.05). The C piglets approached the unfamiliar human later than the I piglets (P < 0.05). The I piglets tended to have more tail lesions than the C group (P < 0.1) during suckling. Tail docking thus induces reactions indicating pain on the day of docking and throughout the suckling period. Evidence of first episodes of tail biting were also found in I pigs. Longer term effects remain to be characterised (pain and bitings).

Impact of straw on gastric ulceration in pigs

Impact of the amount of straw provided to pigs kept in intensive production conditions on the occurrence and severity of gastric ulceration at slaughter.
Herskin MS, Jensen HE, Jespersen A, Forkman B, Jensen MB, Canibe N, Pedersen LJ. 2016. Res Vet Sci. 104: 200-6.

Abstract

This study examined effects of the amount of straw offered on occurrence and severity of gastric lesions in pigs kept in pens (18 pigs, 0.7m(2)/pig) with partly slatted flooring and 10, 500 or 1000g straw/pig/day from 30kg live weight. The pigs had ad libitum access to dry feed. Forty-five pigs were used, three from each of 15 pens. After euthanisia, the dimension of the non-glandular region of the stomach was measured. Lesions were characterized and scored. Irrespective of straw provided, 67% of the pigs showed signs of gastric pathology. Pigs provided with 500 or 1000g straw were pooled as ‘permanent access’. The proportion of pigs with ulcerations was reduced by permanent access to straw (7 vs. 33%; P<0.05), suggesting that permanent access to straw may improve animal health, and be considered as one possible strategy to limit gastric ulceration in pigs.

500gr straw/pig/day
500gr straw/pig/day
10gr straw/pig/day
10gr straw/pig/day

Penile injuries (incl. penis biting) in domestic (& wild) pigs

Penile Injuries in Wild and Domestic Pigs.
By Weiler U, Isernhagen M, Stefanski V, Ritzmann M, Kress K, Hein C, Zöls S. 2016. Animals 6: 4.

Abstract

In boars, sexually motivated mounting can not only cause problems such as lameness, but penile injuries are also reported. The relevance of penis biting in boars is discussed controversially, but reliable data is missing. In the present study, boars ( n = 435) and barrows ( n = 85) from experimental farms were therefore evaluated for scars, fresh wounds and severe injuries of the penis. Similarly, 321 boars from 11 farms specializing in pork production with boars, and 15 sexually mature wild boars from the hunting season of 2015/16 were included in the study. In domestic boars, a high incidence of penile injuries was obvious (76.6%-87.0% of animals with scars and/or wounds at experimental farms, 64.0%-94.9% at commercial farms). The number of boars with severe injuries was in a similar range in both groups (7.3% vs. 9.3%). At commercial farms, the number of scars but not that of fresh wounds increased per animal with age by 0.3 per week. Moreover, raising boars in mixed groups led to about a 1.5 times higher number of scars than in single-sex groups. In wild boars, a considerable proportion of animals (40%) revealed penile injuries, which were even severe in three animals. We therefore conclude that penis biting is a highly relevant and severe welfare problem in the male pig population, but this phenomenon is not limited to intensive production systems.

Notes:
In commerical pig production penis biting is a problem of intact boars. The examined barrows were all free of scars, wounds, severe injuries or suppuration.
For pictures of just how severe penis biting in pigs can be see the article Penisbeissen ein blutiges Phanomen in der Ebermast.