Gender related joint
problems in finisher
pigs
Rijssel, J.A.N. van (Jens)
Background: Joint problems in Dutch finisher pigs related
to gender of finisher pigs
Utrecht University
Department: IRAS
Vion Food Group
location: Boxtel
Nederlandse Voedsel en
Waren Authoriteit
(ministerie EZ)
Supervisor: Dr. L.J.A. Lipman
Abstract
Background: This research was started because Dutch food safety employees had the impression
that more overfilled joints in pigs were observed since the trend of slaughtering more boars instead
of castrates. Therefore the aim of the research became: Determine if there are more affected boars
compared to castrated boars with joint problems. However due the present Dutch situation, the
research question had to be altered because not enough castrated boars were slaughtered.
Therefore the research was aimed to distinguish if there was difference in affected joints between
boars and gilts.
Furthermore this research was organized in order to evaluate what could be the underlying reason
for the joint problems. Therefore also pathology evaluations were performed on random selected
affected joints. This part of the research has to be considered as a good pilot for future research.
Strong suspicions for osteochondrosis are present after the examinations, but no significant
conclusion can be made. A lack of enough data made it impossible to do proper statistics. Also in
order to confirm the suspicion which came up during the research, further microscopically research
should have been done. This trial if interpenetrated as a pilot, can give a good advice what sort of
research should be performed in the future to determine the underlying reason of overfilled joints in
pigs.
1
Table of Content
Abstract ................................................................................................................................................... 1
Table of Content ..................................................................................................................................... 2
Introduction ............................................................................................................................................ 3
Causes of overfilled joints ................................................................................................................... 4
Aim of the research............................................................................................................................. 5
Material and Methods ............................................................................................................................ 6
Evaluation of number of overfilled joints. .......................................................................................... 6
Determination of causes of overfillied joints ..................................................................................... 6
Results and statistical analysis ................................................................................................................ 7
Interpretation ..................................................................................................................................... 7
Discussion................................................................................................................................................ 8
Acknowledgements............................................................................................................................... 10
Bibliography .......................................................................................................................................... 11
Appendix I ............................................................................................................................................. 13
Appendix I.I: Anatomy of the pigs Joints. ......................................................................................... 13
Tarsocrural joint ............................................................................................................................ 14
Intertarsal and distal row .............................................................................................................. 14
Ligaments of the Carpal bones and synovial sacs. ........................................................................ 14
Appendix I.II: Osteochondrosis ......................................................................................................... 17
Bibliography Appendix I .................................................................................................................... 18
Appendix II ............................................................................................................................................ 19
Appendix II.I ...................................................................................................................................... 19
Appendix II.II ..................................................................................................................................... 19
Protocol 1 (used on week 1 and half of week 2)........................................................................... 19
Protecol 2 (used last half of week 2 and week 3) ......................................................................... 21
Appendix III ........................................................................................................................................... 22
2
Introduction
In the Netherlands and Europe discussions were launched about animal welfare situations in pig
production. Several organizations started different campaigns. In the Netherlands organizations as
“Wakker Dier”( a civilian organization) did not agree with the agricultural mindset about how we
should tread agricultural production animals. In their campaigns, for example in the year of 2001
(Dier 2001), they offered free castrations without anesthesia for civil servants of the ministry of
agriculture. This was to get attention for the fact that piglets got castrated using this method in
those days. Not only Wakker Dier participated in the debate. Also “De Dierenbescherming” (
another Animal welfare organization) launched a label for welfare based products from animal
origin(Dierenbescherming 2014). This label has 3 gradations in order to scale how animal friendly the
product is produced. For example, a little more space for finisher pigs is scaled as 1 star and organic
pig farming is labeled with 3 stars.
Not only animal welfare organizations discussed the situations in the intensive livestock farming.
Also farmer associations took part in the public debate. The LTO (general Dutch agriculture
association) and the NVV (Dutch association of pig producers.) played a major role in the debate
about animal welfare in the pig industry. These organizations stated that they are not completely
against what the animal welfare organizations mention, they even agree with them sometimes. But
that they cannot introduce the changes without investments. These investments cannot be paid by
the farmers alone. Other stakeholders of the integration, such as meat processors and supermarkets
should invest as well in the animal welfare measures. Nowadays LTO and NVV are more active to
informe the consumer about how animals are kept as they were in the past.Therefore they use
pictures in order to explain what is happening on the farms(LTO 2007, Rooijakkers, Til et al. 2013).
Not only in the Netherlands such organizations as Wakker Dier, NVV and LTO trigger social debates,
also similar organizations are active in other EU countries trigger the debates. On the European level
there are several organizations active such as Eurogroup for animals (European animal welfare
organization), COPA-COGECA (European farmer and European agri-cooperatives) and the FVE
(Federation of Veterinarians Europe).
In Europe the public debate resulted in governments taking responsibility which resulted in some
agreements, such as a decision to stop castrating piglets without anesthesia or analgesia. These
agreements were captured on paper in the Brussels agreement of 2010 (Union 2010), signed by
European and local associations of the biggest pig producing countries. It was agreed that:
-
Castrating without anesthesia or analgesia would be stopped before 1 January 2012 and that
surgical castration of pigs would be abandoned on the long term (before January 2018)
However not only at European governmental level there has been progress. In the Netherlands most
stakeholders (the farmers, industry and retail) and animal welfare organizations came together in
Noordwijk 2007 and agreed about the Noordwijk Declaration of 2007 (CBL, COV et al. 2007). In this
declaration it is written that supermarket retailers were not going to sell meat of pigs which were
castrated without analgesia or anesthesia by the date of 1 January 2009.
Furthermore they agreed to stop castrating boars by the year of 2015 and, as an intermediate
solution they would allow between 2009 and 2015, castration wit anesthesia or analgesia. This
3
declaration is supported by the Dutch government and the animal welfare organization “De
dierenbescherming” . Next to that the stakeholders also agreed to promote the declaration among
similar stakeholders organizations in other EU countries and in their European umbrella
organizations in order to implement changes on EU level as well.
In a response to the Noordwijk Declaration of 2007 and the Brussels agreement of 2010 research on
issues which were expected to give problems if castration of boars was stopped, was instigated
(CBL, COV et al. 2007, Union 2010).
Subjects looked at were:
-
-
The problem of boar taint, an unwanted smell of the meat as result of the male hormone
regulations. This boar taint is not present in the meat of all animals and can be get identified
when the meat is heated
Growing rate differences between boars and castrates, growing rates of boars are much
more efficient, with higher feed/meat ratio .
Influences of boar behavior. Boars express more jumping behavior as castrates do. How to
control and/or understand this behavior was e.g. looked at by Van der Peet-schwering. (Van
der Peet-schwering, Straathof et al. 2012, Van der Peet-schwering, Binnendijk et al. 2013,
Vermeer, Dirx-Kuijken et al. 2011, Van der Peet-schwering, Troquet et al. 2013)
Nowadays there are pig producers who already introduced the new upcoming rules which would
come into force in 2015. For that reason already a lot of batches of non-castrated boars are
slaughtered in the Netherlands in which also already problems are reported(nVWA ) The Dutch food
safety authority mentioned that in the control at the slaughterhouses more overfilled (meta)tarsal
joints were seen in boars compared to non castrates. The overfilled joints could be caused by
multiple causes, which also can interact with some problems mentioned in literature e.g. boars
behavior or growth rate difference (Van der Peet-schwering, Straathof et al. 2012, Van der Peetschwering, Binnendijk et al. 2013, Vermeer, Dirx-Kuijken et al. 2011, Van der Peet-schwering,
Troquet et al. 2013)
Causes of overfilled joints
In general there are two major causes which can result in overfilled (tarsal) joints. These two major
causes are:
- primarily traumatic causes
- primarily non-traumatic causes.
Some primarily traumatic causes of overfilled joints are known as:
- Distortions
- Intra-articulary contusion
- Peri-articulary contusion
Intra-articulary contusions and distortions give swelling of the joints within the synovial sacs of the
joint and will bulge out, at the places where there are no ligaments in the joint. For more detailed
information about that anatomy: see appendix I.I In case of intraarticulary contusion there is an
inflammatory reaction and possibly a hematoma. (Frandson, Wilke et al. 2009, unknown 2012).
4
A distorsion is a short, unusual friction of the joint which results in a sprain or strain of the ligaments
or in chip fractures. This causes hemarthros, asepticsynoviitis or a purulent arthritis(faculty vet
medicine 2012) Distortions and contusions can be the result of normal behavior of the animals. In
literature several researches describe the behavior of boars, such such as jumping. These actions can
theoretically be a cause of distortion or contusion of the joints. However in the experiments
described they did not observe joint problems. (Van der Peet-schwering, Straathof et al. 2012, Van
der Peet-schwering, Binnendijk et al. 2013, Vermeer, Dirx-Kuijken et al. 2011, Van der Peetschwering, Troquet et al. 2013)
In the primarily non-traumatic category, osteochondrosis is the most mentioned cause of lameness,
often seen in combination with overfilled joints, in literature (Nakano 1987, Ytrehus, Grindflek et al.
2004, Taylor 2013). The etiology of osteochondrosis is multifactorial and partly unknown(Taylor
2013). This disease is present (sub)clinically in 80% of the pigs and has a predisposition for meaty
breeds. (Taylor 2013) .
In case of osteochondrosis, first abnormal development of the cartilage development occurs. These
abnormalities occur in the early development due abnormal nutrition of the cartilage (Thomson
2007). These abnormal nutritional imbalance is caused by a disturbed nutritional diffusion. Which
results in development in – not normal developed – cartilage columns. Normally this layer is a thin
flat layer of cartilage and not a column. In the etiology vascular disruption and hormonal influences
are mentioned as possible factors which may play a role, but this is not good understood so far.
(Nakano 1987, Dijksma 2013)
The second stage of osteochondrosis occurs if there is an erosion of the articular cartilage. This can
occur as result of (micro)trauma on the cartilage. This (micro)trauma of the cartilage will result in
destroyed cartilage. In the final stage painful oesteoarthrosis of the joint can occur. (Taylor 2013,
Thomson 2007)
For this disease –present (sub)clinically in 80% of the pig population- (Taylor 2013) which has an not
completely known etiology, several risk factors has been described (Thomson 2007). These risk
factors are; young rapidly growth, nutritional imbalances, higher bodyweight, genetic predisposition
(more seen in meaty breeds)
For more detailed information about osteochondrosis see Appendix I.II
Aim of the research
The aim of this research assignment was to evaluate if there are more overfilled joints in boars
compared to castrates when the animals arrive at the slaughterhouse. And to determine the cause
of the overfilling of the joints.
5
Material and Methods
Evaluation of number of overfilled joints.
On 3 days, the 25th of June, First and 9th of July, at least two persons monitored all the limbs passing
the slaughter line (of Vion Boxtel) in shifts of half an hour (in order to stay focused, shifts are
needed). During the monitoring, protocols described in Appendix II.I were used and every swollen
(meta)tarsal overfilled joint was tallied. During monitoring persons:
-
-
looked at the limbs and tally.
Observed when the batch changed from boars to gilts, and wrote down the time and
number of the first animal of the next batch. (numbers are out of the computer system of
Vion)
Put red ribbon on swollen tarsal joint
These observations made it possible to calculate by the end of the day, how many piglets passed the
line in total, determine how many boars and how many gilts were slaughtered. And how much
affected animals passed during the experiment from which category.
At the same moment an employee of Vion Boxtel removed affected limbs which were marked with
a red ribbon and placed them in plastic bags together with the ear tag of the pig. These joints were
transported -cooled-, to the pathology unit of the Utrecht faculty of veterinary medicine for further
investigation.
Determination of causes of overfillied joints
During the process two protocols were used, both protocols can be found in appendix III.
During the first part of the research, described in protocol 1 every limb was taken out individually.
First the skin was observed, then an incision was made and the (sub)cutis was observed and finally
the complete joint was opened at the tarsocrural part of the joint due an incision made in the
ligaments (see appendix I.I for the anatomy) while the joint was fixed in a vise. During the
experiment this first protocol turned out to take far too much time to examine all the limbs in the
time. All steps were done in batches of 5 limbs at the same time. So the comments of 5 limbs could
be written down at the same time. Halfway the examination of the joints, the preliminary results
demonstrated lots of varieties. This would result in a results which would make it impossible to run
statistical analyses.
Therefore another protocol was introduced halfway the 2nd week of the experiment. In the 2nd
protocol (see Appendix II) a fixed score was encoded (based on how the cartilage looked like) using 3
categories (“unaffected cartilage”, “not normal, affected cartilage” and “badly affected cartilage”).
These categories made it possible to perform statistical analyses.
Furthermore batches of 8 joints at the same time were examined without changing gloves(in force of
the hygiene protocols). First the skin was examined outside. Then an incision of the tarsocrural joint
ligaments was made (when fixed in a vise). With this method only 1 ones per 8 limbs gloves had to
be changed. Exact details about protocol 2 can be found in appendix III
6
Results and statistical analysis
To get a proper view of the results, all the data collected during the 3 days at Vion were put in one
big dataset of SPSS 20. In this dataset a column “sekse”,” tarsal and metatarsal swollen”, “metatarsal
swollen” and “tarsal swollen” were present. This dataset was used to perform statistical analysis.
Tables from the analyse give an overview of the data tables and results. These tables and results can
be found in Appendix III.
Futhermore another dataset was programmed. This dataset contained data from the pathological
examination. Here the columns: “Sekse”, “Score”, “synovia” and “membrane” were used. Using this
dataset the same statistical analyses was performed. Also a correlation between synovia scores and
membrane scores were calculated. Data Tables and results of the calculations can be found in
Appendix III
Interpretation
To understand the tables of Appendix III , take in mind that that the chi-square test compares the
populations (boars vs. gilts) with a H0: No differences in the population and a H1: There are
differences between the populations. (Petrie, Watson 2013)
Because there is no knowledge about the statistics before this experiment there is chosen for a cutoff point of 0.05 (so P<0.05 it is significant and we can reject H0 and if P>0.05, H0 is not rejected)
According to (Petrie, Watson 2013) “An arbitrary cut-off point of 0.05 is usually chosen for the
significance level”.
Based on those assumptions and the statistical analysis it can be concluded that:
-
There is a significant difference in between the boars and gilts population with affected tarsal
joints. (Boars more than gilts)
There is no significant difference between boars and gilts based on the factor “swollen tarsal
joints’”
There is no significant difference between boars and gilts based on the factor “swollen tarsal
and metatarsal joints”
There is no significance difference in affected vs. unaffected cartilage between boars and gilts
with swollen tarsal areas
There is no significance difference in affected vs. unaffected membrane between boars and gilts
with swollen tarsal areas
There is no significance difference in affected vs. unaffected synovia between boars and gilts
with swollen tarsal areas
There is a correlation of 0,688 between the effected membrane and effected synovia.
So in female pigs we see less overfilled joints, but the overfilled joints are as affected as in male pigs.
7
Discussion
The aim of this research assignment was to evaluate if there are more overfilled joints in boars
compared to castrates when the animals arrive at the slaughterhouse. And to determine the cause
of the overfilling of the joints. Due to changes in the industry there were insufficient castrates
available to perform proper research. Therefore there was chosen to compare boars vs. gilts. In
short, non-significant results are found related to the cause of the overfilling of the joints, although it
is found that boars have significant more affected tarsal joints as gilts. As far as we know, there is no
literature available which described similar research as this trial.
Some inconveniences are present in the used method for this research. As described earlier the
present situation in the Netherlands made it not possible to compare boars vs. gilts instead
therefore there was chosen to compare boars vs. gilts. Also the research is only performed at the
slaughterhouse. Therefore no correlation can be made with farm practices, transporters and
breeding companies.
Also less ideal were the logistics of the observations at the slaughter line. Due the huge amounts of
carcasses coming though within a day the observations were done by two persons (an UU student
and a nVWA employee) in order to stay focused enough. These persons evaluated beforehand how
to determine swollen joints. Still the experiment was done by two persons, in which possible
differences in observation can occur.
Making observations at the slaughter line also has advantages. Due to the protocols and logistics of
the carcasses were clean and without hairs, which made it perfect to observe overfilled joints.
Therefore also overfilled joints which were missed at the ante mortem examination could be found.
In the ante mortem examination the animal were presented in batches and most of the time looked
at from dorsal, which is not the ideal position to examine the limbs.
For the pathology protocols, the biggest inconvenience was the protocol switch halfway the
experiment. Reason to ban protocol 1 and adapt protocol 2 were the many different pathology
descriptions in protocol 1l. In Protocol 2 this was changed with a system where a category had to be
written down. The change in the system with the categories would have made possible to perform
proper statistical analyses on the examined limbs. (for the details of the protocols see appendix II).
However due the late switch, there was not enough data collected to perform statistical analysis.
The aim of the experiment was also to determine the reason why the limbs were swollen. With the
used protocol the cause of the problems could not be determent. Only affected limbs were selected,
so no material was available of limbs which were on examination determined as non-affected.
Therefore was it not possible to determine whether there was also a subclinical joint problems.
Therefore this experiment should be considered as a pilot and should be repeated to come to
significant conclusions.
The underlying cause of swollen joints could not be determined performing only macroscopic
examinations. For example one of the possible reasons which could cause the kind of trauma which
was observed at marcrosopical examination is osteochondrosis .(Taylor 2013, Sjaastad, Sand et al.
2010, Thomson 2007). But osteochondrosis has to be confirmed by microscopically examination
(Thomson 2007).
8
Furthermore swollen joins can also be caused by infectious or traumatic causes. Infectious problems
seem less presumably because limbs are seen swollen over the complete population Dutch piglets.
A problem spread through the whole population, can have a genetic predisposition (osteochondrosis
for example) or a behavior related problems (such as (dis)torsions and contusions due to jumping
behavior).
In literature nothing is published about the relationship of swollen joints to jumping behaviour. It
has been observed that boars jump more often compared to castrates(Van der Peet-schwering,
Straathof et al. 2012, Van der Peet-schwering, Binnendijk et al. 2013, Vermeer, Dirx-Kuijken et al.
2011, Van der Peet-schwering, Troquet et al. 2013). But no literature was found about consequences
of this behavior in relation to joint problems. A relation between jumping and joint problems can
theoretically exist. A failed jumping attempt could results in a (dis)tortion. Also pressure on the joint
cartilage could occurs during a (failed or succeed) jumping attempt which can be a complication
factor in the last phase of osteochondrosis.
Extra research has to be performed to determine the possible reason of overfilled joints .
Furthermore research has to be performed to determine if osteochondrosis is present in the Dutch
pig population (clinically or subclinically). In literature (Taylor 2013) reported a prevalence of 80%
(sub)clinical osteochondrosis in meaty pig breeds (Taylor 2013).
Furthermore it was reported that swine are the only species where there is no difference in
prevalence of osteochondrosis between male and female (Thomson 2007).
If the jumping behavior of boars causes more swollen joint it remains the question if and how much
those affected animals suffer? A discussion could be launched what has more negative influence on
animal welfare influence castrating boars or swollen tarsal joints. In this discussion it has to be taken
into account that these swollen tarsal joints are observed at the post mortem examination and not
when the animals arrive at the slaughterhouse at the ante mortem inspection. Not showing clinical
symptoms can indicate that the animals with the overfilled joints do not experience a lot of pain.
An extra point which has to be discussed is the aspect of food safety. What should be done with the
swollen joints. If it is an sterile aseptic synovitis (by distortion, or osteochondrosis) which causes the
overfilled joints, there is not much reason to be concerned about food safety. If the swelling is
caused by an infectious disease food safety can be questioned. At the slaughter line it is not possible
to distinguish between sterile or infectious origin.
According to an veterinary employee of the Dutch food safety organization there is an protocol to
act if swollen joints are seen (Rooijakkers 2013).
This protocol is based on two aspects:
1. When the swelling of the joint is observed ante mortem, the official vet. classifies it as cat. 2
material. Then the pig will be slaughtered on lower speed with extra supervision. (Rooijakkers 2013)
2. When the swelling of the joint is observed post mortal, the KDS assistance (assistance of the food
safety veterinarian) marks the limb and the carcass gets selected out (Rooijakkers 2013), Then the
limb gets amputated and the remaining carcass goes for human consumption if no systemic
9
problems are observed, if these problems are observed a governmental veterinarian will check the
animal and will probably send the whole carcass of for destruction(Rooijakkers 2013)
Maybe in the future new campaigns will be launched by organizations as LTO or Wakker Dier. If
these campaigns are going to be based on facts depends partly on how fast future research will be
performed.
Acknowledgements
First I would like to thank my supervisor Len Lipman for all the help he gave me. Especially during the
last weeks/months. He helped me really well with all my really bad writing in English. Without his
patience and suggestions over and over again I would never have come to this result.
Also I want to thank the nVWA and VION Boxtel, because without them I would not had a research
at all. Especially Hans Rooijakkers (nVWA) for his supervision during my time at the slaughterhouse
VION Boxtel, Also I want to thank all the KDS assistances for the humor they presented me at the
slaughter line, which made the time more fun.
Furthermore I want to thank the Pathology department. Jaime Rofina for his help when I was making
my protocols for my research, Louis van den Boom for his advice which helped me out with practical
issues I had faced in the pathology roam, Guy Grinwis for showing me one of his protocols used in a
bovine research which has been the basis for my protocol 2.
Also I want to thank Claudia Wolschrijn which showed me the only literature available about the
anatomy of a pig tarsal joint. Myself I would never have searched in French terms.
10
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Appendix I
Appendix I.I: Anatomy of the pigs Joints.
The anatomy of the hind limb joints, and especially the tarsal and the metatarsal joints are essential
in order to understand this research. The tarsal joint in General of Domestic Mammals look like fig 1
(Liebich, König et al. 2014)
Fig 1: A lateral view (bovine)
B cranial view (equine)
C cranial (bovine)
Adapted from: (Liebich, König et al.
2014)
(Liebich, König et al. 2014): our Domestic mammals the tarsal bones are arranged in three rows,
knowing:
1. Proximal row: articulates with the tibia (known as the Tarsocrural joint)
2. Intertarsal row: articulates with each other in a complex fashion.
3. Distal row: Articulates with the metatarsal bones (known as the tarsometatarsal joint)
The intertarsal row is different within different species (fig 2) (Liebich, König et al. 2014). For pigs the
original situation with seven tarsal bones is maintained, non-adhesion is observerd in swine.
Together the seven Tarsal bones form all the Tarsal joints.
13
Fig 2. Tarsus in domestic mammals (schematic) Adapted from (Liebich, König et al. 2014)
Tarsocrural joint
The Tarsocrural joint is a joint formed by the tibia and the Talus (one of the tarsal bones). This Talus
exist out of two major structures, the corpus tali (compact body) and a trochlea (Trochlea tali). This
bone has prominent sagittal ridges dorsoproximal and a caput tali (head) which fit in into the
intermediate ridge of the distal end of the tibia. (Liebich, König et al. 2014)
Intertarsal and distal row
Next to Talus we can find the Calcaneus (Os tarsi fibulare), this Tarsal bone provides movement
independent from the Talus. (Liebich, König et al. 2014)
The major function of the calcaneus is provide movement of other carpal bones. The Calcaneus
pushes the 4th tarsal bone forward which pushes the other tarsal bones (the middle 1st 2nd and 3th
tarsal bones) in the same direction. This calcaneus can slide if necessarily from mediodorsal to partly
mediocaudal from the Talus pushing the tarsal bones and the other parts caudal from its position
into a hook. (Liebich, König et al. 2014)
Also the calcaneus is a quite enlarged and tarsal bone which also extend and has function as a lever
for the muscles such as the gastrocnemius muscle extend the hock of the joint. (Liebich, König et al.
2014)
Ligaments of the Carpal bones and synovial sacs.
The Tarsal bones and joints are kept together due multiple ligaments (Liebich, König et al. 2014) and
covered in multiple synovial sacs. The anatomy of these ligaments together with the places of the
synovial sacs will set the points where you can observe whether the joint is overfilled or not.
14
Like in all synovial joints the ligaments have as function to keep the joint together and consist of firm
fibrous connective tissue (Sjaastad, Sand et al. 2010). For that reason it is always necessary to use
force from muscles to prevent the joints for over-extension of over-flexion. The synovial sacs
provide movement between the bones without high friction, due the production of synovial fluid.
Also they enclose the complete joint in order to keep the fluid in the joint. Next to those functions
the synovia also contains nutrients for the chondrocytes. (Sjaastad, Sand et al. 2010).
In the Pig there is no tarsal bone that joined together. Although they have a lot of different
ligaments in their tarsal joints, especially if you look at the dorsal view of the tarsal joint anatomy (fig
3, 4 and 5)
Fig. 3: Medial view of the porcine
tarsal joints with ligaments, bones
and muscles.
Adapted from: (Barone 2000)
15
Fig. 4: Dorsal view of the
porcine joints including
ligaments, bones and muscles.
Adapted from: (Barone 2000)
Fig 5: lateral view of the porcine tarsal
joints including bones, ligaments and
muscles.
Adapted from: (Barone 2000)
16
In the Tarsal joints the synovial sacs are separated in three different sacs which normally do not
communicate with each other.
Appendix I.II: Osteochondrosis
Osteochondrosis (OC) is a degenerative generalized skeletal disease. OC can occure with leg
weakness before the age of 18 months. The main problem with OC is related to errors in the
ossification process. The final stage of this disease results in erosion of the articular cartilage and can
cause painful oesteoarthrosis of the joint.(Taylor 2013, Sjaastad, Sand et al. 2010, Thomson 2007)
These have a degree of change in about 80% of the pigs. With a predisposition for the more meaty
breeds such as Dutch Landrace, Swedish Landrace or Duroc. (Taylor 2013)
How the exact ethology and pathogenesis is still unclear. There are histological lesions found in 1 day
piglets which indicate for a congenital component. (Taylor 2013) Next to that there are theories that
involve a multifactorial etiology is the most likely. Factors which play part in the multifactorial theory
are trauma or biomechanical factors on cartilage, weakened cartilage due hormonal influences,
nutritional imbalances, vascular disruption during early bone development and some unknown
genetic factors.
About the nutrition of the joint, in adults this is regulated due synovial fluid in the joints (if the bone
is in an adult stage). At the age of two weeks the joints are still completely vascularized, this reduces
slowly. At 4-5 months they are macroscopic avascular. During it is possible that an interruption of
the bone channel (which contains the bone arteries) occurs. In growing pigs (around 2 months old)
this can result in necrosis of subarticular epiphysis cartilage. Because of that reason young rapidly
growing pigs have a higher chance to develop OC(Thomson 2007).
Later this can heal spontaneously (when the necrotic areas are small) or develop into a cartilage flap.
Also this flap can remain stuck to the other cartilage or can become separate. In mice’s it is
observed that it can either result in losing the joint or get attached to the synovial membrane. If this
happens it is called osteochondrosis dissecans, here almost always inflammatory changes in the
synovium are observed. These inflammatory changes go along with overfilled joints. (Thomson
2007)
Alos in multiple species genetic backgrounds are observed. Humans are known to have families with
higher and lower prevalances. In animals also several genetic li9nes are indicated to have higher
prevelences as others, for example stanbred horses (h2=0.24-0.27). Also multiple trials prove that in
different species there are relations which show that rapid growth predispionates for OC. The same
rapid growth might be a cause for the trauma which can cause the flap turn in to a mice with higher
weight bearing on the surfaces predispionates for trauma. Also the nutritional influences remain not
determent. The last factor which could play an important role but is still unknown in pigs is the
variety of hormones who have been implicated in the etiology of OC. For example, the Growth
hormone known from dogs(Thomson 2007).
17
Bibliography Appendix I
BARONE, R., 2000. Articulations du tarse 4. Particularités spécifiques.. Porc. Anatomie comparée des
mammifères domestiques. 4e edn. Paris: Vigot, pp. 351-352, 353.
LIEBICH, H., KÖNIG, H. and MAIERL, J., 2014. Hind limbs or pelvic limbs (membra pelvina).
SJAASTAD, O.V., SAND, O. and HOVE, K., 2010. Bone Tissue and Mineral Metabolism. In: O.V.
SJAASTAD, O. SAND and K. HOVE, eds, Physiology of domestic animals. Second edn. Oslo:
Scandinavian veterinary press, pp. 260-260-278.
TAYLOR, D.J., 2013. Miscellaneous conditions. In: D.J. TAYLOR, ed, Pig diseases.
THOMSON, K., 2007. Diseases of joints. In: M. GRANT, K. JUBB, P. KENNEDY and N. PALMER, eds,
Pathology of domestic animals. 5th edn. Estados Unidos: Saunders, pp. 131-until183.
18
Appendix II
Appendix II.I
Time + Nummer+boars or gilts
Start
end
Tarsal and
metatarsal
swolen
* Only
Tarsal
Swolen
*
Only
metatarsal
swolen
* Amound
selected for
experiment 2
M/F:
Time:
Number
M/F:
Time:
Number
Table used to tally how pigs affected, and how much pigs observed totally.
The columns with * are to tally how many had both hind limbs affected
The last column is to tally the amounts of castrates in order to correct afterwards.
Appendix II.II
Protocol 1 (used on week 1 and half of week 2)
Step1: examination of the skin outside
Limb
nr.
1.
2
Color
Swollen? Locally or
diffuse?
Ulceration?
Bleeding?
crustae
Table for writing down the results during examination of protocol 1, step 1 examination skin
A
B
Reference pictures for step 1
C
A: Normal color of the skin, not swollen.
B and C: Sub dermal bleeding, on B you can see clear color difference.
19
Castrates
Step 2: Cut open, scalpel the skin and examination of the subcutis after we made an incision into the
dermis.
Limb Swollen?
Oedema?
Bleeding?
Imflamatoiry aspects?
nr.
1.
2
table for writing down the results during examination of step 2 examination of the subcutis
A
B
Reference* pictutrers for step 2
A: Normal subcutis
B subcutis with oedema
Step 3: Open the joint itself (incisions into the muscles, ligaments and).
Poot
nr
1.
2
Aspect of
synovia fluid
Joint membrane
thin and white?
Trochlea of
thalus.
Bone?
Hyperemic /imflamatoiry?
table for writing down the results during examination of step 3 the tarsocrual joint.
A
Reference step 3*
membrane
A normal membrane
B
B: swollen membrane
C
C: hyperemic swollen
*Although there were reference pictures. For all steps of the protocol there were still too much
variations in descriptions to perform further statistical analysis. Also non clear cartilage scores were
included in protocol 1.
20
Protecol 2 (used last half of week 2 and week 3)
Follow number:
UBN number (unit number every farm has):
Normal skin? Color? Swollen? Ulceration? bleeding? Crustae?
Dermis/subcutis: Swollen? Oedema? bleeding?, Inflammatory aspects?
Joint: synovia? Membrane?
Bone (defects: draw on the bone picture)
Cartalage defects
Score:
Lateral
Medial
Lengt (mm)
Wide (mm)
depth
Opposite Joint surface
(the opposite site as
the defect.)
Comments
21
Pig number:
As in Protocol 1 this protocol gives room for a lot of interpretation and different possible notes in
the different tables. The crucial difference between protocol 1 and 2 is that the part of: “Score: “.
This made it possible to determine good cut-off values in order to perform statistically analysis. The
“Score” had 3 different categories, where the limbs are categorized in. Futhermore there is less
focus on skin and dermis and more on the joint. In this protocol everything is examined as good as
possible with a opened joint. Due those changes it is less specific for scores of skin and subcutis. But
it is possible to determine more joints in less time, because also time was a problem with protocol 1.
Reference pictures for the “Score,,:
1: normal
2: not normal affected
3: badly affected
A
Gradation 1 (A)
BB
C
Gradation 2 (B)
22
Gradation 3 (C)
Appendix III
III
Appendix
We got the following Cross-tabs after running the 2 x 2 Chie-square test analyses on SPSS 20.
The data table (below on the left) and the table with SPSS 20 calculations (below on the right). First
the table’s from the big dataset of Vion is presented. In all tables sekse 0 = Gilts and sekse 1 = boars.
Table 1
Table 2
Tarsal and metatarsal swollen
Tarsal and metatarsal swollen
A0= non affected
A1= affected
A
0
Sekse
The Asymp. Sig (2 sided) P>0,05
Total
Df
1
0
4701
0
4701
1
5103
3
5106
9804
3
9807
Total
Value
Pearson Chi-
Asymp.
Exact
Exact
Sig. (2-
Sig.
Sig.
sided)
(2-
(1-
sided)
sided)
,251
,141
2,763a
1
,096
1,176
1
,278
3,917
1
,048
Square
According to table 1 and 2 there is no
significant difference in tarsal and
metatarsal swollen joint between gilts
and boars.
Continuity
Correctionb
Likelihood Ratio
Fisher's Exact Test
Linear-by-Linear
2,763
1
,096
Association
N of Valid Cases
9807
a. 2 cells (50,0%) have expected count < 5. The min. expected count is
1,44.
Table 3
Table 4
Tarsal swollen
Tarsal swollen
B0= non affected
B
0
Sekse
Total
The Asymp. Sig (2 sided) P<<0,05
B1= affected
Value
Total
df
1
0
4643
58
4701
1
4835
271
5106
9478
329
9807
Pearson Chi-
Asymp.
Exact
Exact
Sig. (2-
Sig.
Sig.
sided)
(2-
(1-
sided)
sided)
,000
,000
125,277a
1
,000
124,024
1
,000
136,804
1
,000
Square
Continuity
According to table 3 and 4 there is a
significant difference in swollen joint
between gilts and boars.
Correctionb
Likelihood Ratio
Fisher's Exact Test
Linear-by-Linear
125,265
1
,000
Association
N of Valid Cases
9807
a. 2 cells (50,0%) have expected count < 5. The min. expected count is
157,71
23
Table 5
Table 6
Metatarsal swollen
Metatarsal swollen
C0= non affected
C1= affected
C
Sekse
The Asymp. Sig (2 sided) P>>0,05
Total
0
1
0
4688
13
4701
1
5083
23
5106
Total
9771
36
9807
According to table 5 and 6 there is a
significant difference in swollen joint
between gilts and boars.
Value
Pearson Chi-
df
Asymp.
Exact
Exact
Sig. (2-
Sig.
Sig.
sided)
(2-
(1-
sided)
sided)
,182
,104
2,024a
1
,155
1,577
1
,209
2,057
1
,151
Square
Continuity
Correctionb
Likelihood Ratio
Fisher's Exact Test
Linear-by-Linear
2,024
1
,155
Association
N of Valid Cases
9807
a. 0 cells (0,0%) have expected count < 5. The minimum expected count is
17,26.
Then also on the other dataset with the data collected in the pathology. Were examined and also
the 2 x 2 Chie-square test analyses runned in SPSS 20. Also in this dataset tables sekse 0 = Gilts and
sekse 1 = boars. Although this time it is out of a population of already affected animals.
Table 8
Table 7
Sex vs. synovia
Synovia: 0=transparant 1=yellowisch/ red
Synovia
0
sekse
Total
The Asymp. Sig (2 sided) P>>0,05
Total
Value
1
0
0
12
12
1
2
39
41
2
51
53
According to table 7 and 8 there is no
significant difference affected synovia
between gilts and boars.
Pearson Chi-
df
Asymp.
Exact
Exact
Sig. (2-
Sig.
Sig.
sided)
(2-
(1-
sided)
sided)
1,000
,595
,608a
1
,435
,000
1
1,000
1,050
1
,306
Square
Continuity
Correctionb
Likelihood Ratio
Fisher's Exact Test
Linear-by-Linear
,597
1
,440
Association
N of Valid Cases
53
a. 2 cells (50,0%) have expected count < 5. The minimum expected count
is ,45.
24
Table 9
Table 10
Membrane: 0= normal 1= (red +) swollen
Sex vs. membrane
membrane
0
sekse
the Asymp. Sig (2 sided) P>>0,05
Total
Value
1
df
Asymp.
Exact
Exact
0
0
12
12
Sig. (2-
Sig.
Sig.
1
2
39
41
sided)
(2-
(1-
2
51
53
sided)
sided)
1,000
,595
Total
Pearson Chi-
,608a
1
,435
,000
1
1,000
1,050
1
,306
Square
According to table 9 and 10 there is
no significant difference affected
membranes between gilts and
boars.
Continuity
Correctionb
Likelihood Ratio
Fisher's Exact Test
Linear-by-Linear
,597
1
,440
Association
N of Valid Cases
53
a. 2 cells (50,0%) have expected count < 5. The minimum expected count
is ,45.
Table 11
Table 12
Cartilage score 0(normal), A1= score 0,
Sex vs. affected cartilage
A0= different score
The Asymp. Sig (2 sided) P>>0,05
A
0
sekse
Total
Value
Total
df
1
0
8
4
12
1
21
20
41
29
24
53
Pearson Chi-
Asymp.
Exact
Exact
Sig. (2-
Sig.
Sig.
sided)
(2-
(1-
sided)
sided)
,512
,271
,894a
1
,344
,379
1
,538
,911
1
,340
Square
According to table 10 and 11 there is
no significant difference affected
cartilage between gilts and boars.
Continuity
The other factors of how much
effected cartilage was is not
calculated, because this cannot be
significant if this already is not
significant.
Fisher's Exact Test
Correctionb
Likelihood Ratio
Linear-by-Linear
,877
1
,349
Association
N of Valid Cases
53
a. 0 cells (0,0%) have expected < than 5. The minimum expected count is
5,43.
25
Table 12
Table 13
Membraam:
Synovia:
Pearson: 0,668 with P<<0,01
0= Normal
0= transparent
1= Swollen
1= Yellowisch
2= Hyperemic swollen
2= red
Synovia
Total
1
Pearson Correlation
membraam
1
,668**
,000
Sig. (2-tailed)
membrane
0
synovia
synovia
Total
N
53
53
,668**
1
2
0
2
0
0
2
1
0
24
4
28
2
0
7
16
23
2
31
20
53
membraam
Pearson Correlation
Sig. (2-tailed)
N
,000
53
53
**. Correlation is significant at the 0.01 level (2-tailed).
According to table 12 and 13, there is a significant correlation within the grades (cut-off values of this research) of
how affected the membrane is in relation to how abnormal the synovial fluid is. This correlation is 0,668.
26