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Welfare implications of care and procedures performed on suckler pigs

Leana Janse van Rensburg
In today’s society the issue of animal welfare is becoming more prominent, especially in first-world countries, where consumers expect the animals raised and slaughtered for consumption to be treated humanely.
In veterinary circles the most common measure used to assess welfare is based on the five freedoms of Webster:
–    Freedom from thirst, hunger and malnutrition
–    Freedom from discomfort
–    Freedom from pain, injury and disease
–    Freedom to express normal behaviour
–    Freedom from fear and distressThese freedoms are impossible to obtain as an absolute criteria, because in order to obtain one freedom (e.g. freedom from disease) one may have to contravene another freedom (e.g. freedom from discomfort during vaccination). The situation also becomes complicated, as optimising one group of animals’ freedoms may negatively influence another group’s freedoms (e.g. keeping sows in farrowing crates to prevent the overlie of piglets).
The current draft of the South African Code for the Welfare of Pigs attempts to put welfare standards in place, which are addressing the issues that concern both the public and veterinary peers in other countries.
The Welfare Code provides details on what is acceptable in terms of handling; in terms of procedures being performed on pigs; in terms of housing for pigs; and various other details aimed at optimising the wellbeing of the animals and providing brief justification for the necessity of activities that contravene the five freedoms.
Handling of sucklers
The Welfare Code states: “Stock workers and owners must be appropriately trained to handle pigs and perform routine procedures in a manner that is hygienic and causes minimum discomfort.”
It has been well documented that handling and restraint are stressful to piglets and cause a great deal of fear and distress, as well as discomfort (Lewis, E.; Boyle, L.A.; Lynch, P.B.; Brophy, P. & O’Doherty, J.V. 2005). It naturally follows that the handling of sucklers should be kept to a minimum and should only take place with a specific purpose in mind, while the time required to restrain the piglets should be kept as brief as possible.
The accepted method of picking up a piglet is to catch it by its back leg, above the hock, and then wrapping it around your arm so as to provide body support. It is not acceptable to catch a piglet by its front leg, as the shoulder joint tissue connections are very soft and could easily be dislocated.
Elective procedures
1. Castration
Castration is a means of preventing “boar taint” – i.e. the presence of unacceptable odours and flavours in pork, causing it to smell “off” – in pork, which is caused by male androgens and skatoles. This could have a serious effect on consumer preference, if consumers should happen to come across such a piece of pork.
In lambs and calves the testes are externalised, and methods such as the use of a rubber ring or burdizzo, may be utilised for castration purposes. However, where pigs are concerned, surgical castration is the only viable physical means of castration (Taylor, A.A. & Weary, D.M. 2000).
With regard to surgical castration, the Welfare Code states: “Castration of male sucklers up to the age of seven days. Any piglet older than seven days may not be castrated, except by a veterinarian and with the use of an anaesthetic.”
However, in a study assessing behavioural responses as a measure of pain during castration at the ages of 3, 10 and 17 days respectively, no difference was found in the response when comparing the age groups (Taylor, A.A.; Weary, D.M.; Lessard, M. & Braithwaite, L. 2001). Other articles corroborate the finding that castration during the first three days is evidently painful and that inflammation of the area increases the pain (Von Borell, E.; Baumgartner, J.; Giersing, M.; Jäggin, N.; Prunier, A.; Tuyttens, F.A.M. & Edwards, S.A. 2009).
This may indicate that the assumption, that neonatal animals younger than seven days are less sensitive to pain, needs to be questioned and further investigated.
It is well known that in Europe there has been growing concern regarding the welfare implications of castrating sucklers without anaesthesia and that this practice may be banned in the near future (Heid, A. & Hamm, U. 2009).
There are indications that topical anaesthetics do not sufficiently reduce the pain inflicted by castration (Sutherland, M.A.; Davis, B.L.; Brooks, T.A. & McGlone, J.J. 2010) It has, however, been reported that general and local anaesthesia, administered in conjunction with analgesics, do limit the indication of pain experienced, but that the additional handling and restraint actually cause additional distress (Von Borell, E. et al. 2009).
It has been noted that general anaesthesia results in delayed piglet recovery, since there are decreased heat-seeking behaviour and nursing after the anaesthesia, which also impact negatively on the welfare of the piglets (Taylor, A.A. & Weary, D.M. 2000).
Behavioural studies indicated that castrated piglets displayed more distress (measured as high frequency vocalisation) than piglets that had received a local anaesthetic before castration, or littermates that had been restrained without castration (Taylor, A.A. & Weary, D.M. 2000). In the same study, it was determined that the pain response was the same in severing the spermatic cord by means of tearing; pulling; or cutting it with a scalpel. Anecdotally it was noted that there was less bleeding with the pulling method than with the cutting method.
From existing literature it is evident that the castration of sucklers has serious welfare implications, regardless of the age at which castration took place or whether an anaesthetic was used. Therefore, it is important to explore possible alternatives to castration.
The first would be to slaughter male pigs before they reach sexual maturity (i.e. before six months), causing the risk of “boar taint” to be minimal. It also has the added benefit for producers that the intact male animals display extra growth (Taylor, A.A. & Weary, D.M. 2000). This may, however, impact negatively on the welfare of the intact finisher pigs, as there will be more fighting amongst them with the accompanying injuries (Von Borell, E. et al. 2009).
Another option would be to select animals with a view to later sexual maturity (Taylor, A.A. & Weary, D.M. 2000). This process, however, carries the consequence that some carcasses, affected by “boar taint”, would be produced. However, to truly achieve the highest standard of welfare, this may be an acceptable price to pay (Von Borell, E. et al. 2009).
One can also use consider “immuno-castration” by means of an anti-GnRH vaccine, such as Improvac©, which causes the regression of the testicular tissue via the animal’s own immune system (Taylor, A.A. & Weary, D.M. 2000). The vaccine functions by administering a priming dose, which has no immediate effect, and therefore the boars will still show improved growth. This is then followed by a second dose during the finisher stage, which affects growth.
This method should, however, only be used under the supervision of a veterinarian, as the consequences could be severe, should workers accidentally inject themselves twice. It has been shown that, following the injection of Improvac©, there was a decrease in activity in the treated animals that may be attributed to the inflammation caused by the subcutaneous administration (Von Borell, E. et al. 2009).
An important factor that needs to be taken into consideration is what the consumer would actually find acceptable as an alternative to castration (Heid, A. & Hamm, U. 2009). Questions pertaining to residues and long-term implications, related to the consumption of pork originating from pigs that underwent “immuno-castration”, remain pertinent amongst consumers.
From existing literature it becomes clear that there is evidence that an age limit of seven days may be inadequate and that further revision may be necessary. It was, however, noted that castration of neonatal pigs resulted in improved wound healing (Von Borell, E. et al. 2009).
2. Tail docking
The Welfare Code states that tail docking is not approved as a routine procedure. Pig’s tails should be left intact unless recommended by a veterinary consultant for particular farms as a necessary procedure. Where tail docking is practised, it must be done before piglets reach the age of seven days, and not more than half the length of the tail should be removed.
Tail docking was introduced as a method of preventing tail biting, which can be quite severe with tails being bitten right up onto the back. The rationale is that the last third of the tail has deficient innervation, resulting in the problem that piglets do not react when the tip of the tail is being bitten. Once the tip is bleeding, piglets are attracted to the blood and continue to bite the tail .This could result in spinal abscesses, infection and pain, and has serious welfare implications. To combat this, half the tail is removed with side cutters or a scalpel blade, which results in the tail being well innervated, which will cause the piglet to move away or fight back when bitten by another piglet.
The causes of tail biting is listed in the Welfare Code as follows:
– Poor nutrition: deficiency in protein, minerals or the amount of food.
– Overcrowding, bad ventilation, the development of ammonia or rotten gas.
– Bullying, boredom, over-stocking, poor hygiene, insufficient available water or other poor management practices.
This therefore indicates that the causes are man-inflicted and can be circumvented rather than imposing another painful procedure on the piglet.
Tail docking is a distressing procedure, resulting in abnormal behaviour, such as tail jamming and wagging, as well as grunting (Noonan, G.J.; Rand, J.S.; Priest, J.; Ainscow, J. & Blackshaw, J.K. 1993). It can furthermore be extrapolated from the discussion on castration above, that a seven-day limit may need to be further investigated, as piglets younger than seven days are just as responsive to pain (Taylor, A.A. et al. 2001).
Another study indicated that, providing the piglets with long straw twice a day, greatly reduced the incidence of tail biting, as well as decreased the severity of an outbreak of tail biting (Zonderland, J.J. 2010).
Furthermore, proposals were made to prevent the incidence of tail biting via environmental enrichment; by predicting the incidence by means of tail posture; and counteracting an outbreak by removing the biter(s) (Zonderland, J.J. 2010).
3. Tooth clipping
At birth, piglets have eight canines, used to fight for, and defending their teat. This gives rise to injuries on the faces of piglets (Lewis, E. et al. 2005). This has resulted in the routine clipping of these eight canine teeth within 24 hours of birth.
In this regard, the Welfare Code states: “Tooth clipping is not approved as a routine [procedure] and should only be done where damage to sows’ udders and/or siblings occurs”. This is in line with EU legislation, where the practice is actually discouraged (Lewis, E. et al. 2005).
With this procedure, stereotype behaviour in the form of teeth champing occurs yet again, once again indicating that the piglets are actually experiencing distress (Noonan, G.J. et al. 1993).
The Welfare Code lists the causes as follows:
– There are too many piglets for the sow to feed simultaneously.
– The sow does not have enough milk, due to insufficient feed or water or the wrong kind of feed.
– The sow has mastitis or another painful condition in one or more udder sections and is unwilling to allow the piglets to suckle.
This again points to management problems that need to be addressed in order to circumvent this procedure, since it has serious welfare implications – for example when clipping is done erroneously, resulting in wounds on the tongue and lips, or in the tooth breaking into splinters, which could result in infection (Lewis, E. et al. 2005).
In instances where this procedure is necessary, teeth grinding is preferable, as it has fewer side-effects and causes less acute pain (Lewis, E. et al. 2005).
4. Ear notching and tattooing
The Welfare Code states: “Ear notching by trained personnel is allowed up to seven days of age”.
Noonan, G.J. et al. (1993), found that ear notching resulted in the stereotyped behaviour of head shaking. However, it was found that the distress caused was not of long duration.
Tattooing has no age limit, according to the Welfare Code. This may have welfare implications, but permanent identification is required by South African legislation.
5.  Euthanasia
On the subject of euthanasia, the Welfare Code states: “Euthanasia must be performed on pigs that are suffering unduly and whose chances of full recovery from disease or injury are unlikely”.
The suggested methods for sucklers are:
–    CO2
–    A penetrating captive bolt
–    An anaesthetic overdose
–    Blunt-force trauma
As sucklers generally are found dead or die very quickly, one may not have much opportunity for practising euthanasia. However, in cases of severe septic arthritis and other serious diseases for which the prognosis is poor, it is in the interest of maintaining welfare not to allow the piglets  to suffer.
Housing
Most sucklers die due to starvation and overlie (Anderson, I.L.; Tajet, G.M.; Haukvik, I.A.; Kongsrud, S. & Bøe, K.E. 2007). The crushing of piglets can be reduced by effective housing. Piglets should have a warm area away from the sow to prevent situations of overlie, as well as rails on at least three walls when a farrowing pen is used (Anderson, I.L. et al. 2007).
Flooring plays an important role, as rough flooring causes lesions on the knees of piglets while suckling, as well as claw lesions (Norring, M.; Valros, A.; Munksgaard, L.; Puumala, M.; Kaustell, K.O. & Saloniemi, H. 2006). In this study it was found that, under extensive conditions, where sows can build nests, the position of the piglets was such that they did not need to go onto their knees.
The flooring should also not be slippery, as this could impact on the piglets’ ability to walk (Norring, M. et al. 2006).
Care of piglets
The greatest piglet mortality occurs during the first three days post partum. Therefore, in order to promote the welfare of piglets, this particular mortality should be kept to a minimum by increased vigilance, as well as assistance to the piglets (Anderson, I. L. et al. 2007).
This could take the form of a farrowing assistant performing specific routines, such as:
– drying the piglets after birth;
– tying off the umbilicus when necessary;
– placing the piglets near a heat source to limit heat loss;
– putting the piglets on a teat to receive colostrum;
– cross-fostering large litters, as well as piglets from sows suffering from inadequate milk production; and
– supplying bedding for the piglets.
These routine measures have proven to decrease piglet mortality (Anderson, I. L. et al. 2007).
The weaning age is also a contentious welfare issue, with behavioural studies indicating that weaning piglets at 21 days impacts negatively on the welfare of the piglets (Mason, S.P.; Jarvis, S. & Lawrence, A.B. 2003). This again needs to be compared to the decreased disease risk associated with early weaning, as the piglets still have maternal immunity when they are removed from the greatest source of infection, namely adult pigs.
Welfare trade-offs
With sucklers and sows there is a welfare trade-off that has to be made, as the confinement of sows in a farrowing crate impacts negatively on their welfare. It has, however, been proven that, keeping lactating sows in a pen extensively (or organically), increases the piglet mortality rate and thus decreases their welfare (Wallenbeck, A.; Gustafson, G. & Rydhmer, L. 2009).
It was noted that lactating sows, that are kept in an extensive set-up, make better mothers, they are being more careful around piglets and they display better nursing behaviour (Wallenbeck, A. et al. 2009). Therefore, a measure of the mortality in an organic setting could be negated by opting for better mothering abilities, but piglets will still experience greater exposure to the elements and extremes of temperature, with the added disadvantage that it is difficult for attendants to intervene when necessary. The Welfare Code states that shelters need to be provided for outdoor systems, but it would be very difficult to provide the piglets with an environment that facilitates the elimination of discomfort in an outdoor system.
A compromise may need to be reached by keeping the sow in a farrowing crate during the most dangerous period only,  namely the first three days, and then to move them to an environment where the sow can move around freely, while the welfare of the piglets is accommodated by the following methods:
– Putting rails around the bottom of solid walls to prevent crushing.
– Providing a heated creep area.
– Providing sufficient bedding for both the piglets and the sow to allow for    normal nursing.
Conclusion
The care and handling of sucklers should be done in such a way as to promote the welfare of the piglets, as this increases productivity, as well as fulfils man’s moral obligation to care well for the animals that are at his mercy. Poor welfare is a growing concern for the consumer and, as such, veterinarians should be the forerunners in promoting good welfare practices and providing scientific justification when painful procedures are being practised.
References
1. Anderson I L, Tajet G M, Haukvik I A, Kongsrud S, Bøe K E 2007 Relationship between postnatal piglet mortality, environmental factors and management around farrowing in herds with loose-housed, lactating sows. Acta Agricultura Scand Section A 57: 38- 45
2.    Heid A, Hamm U 2009 Consumer acceptance of alternatives to piglet castration without anaesthesia. Fleischwirtschaft 89, 12: 93- 98
3. Lewis E, Boyle L A, Lynch P B, Brophy P, O’Doherty J V 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
4. Mason S P, Jarvis S, Lawrence A B 2003 Individual differences in responses of piglets to weaning at different ages. Applied Animal Behaviour Science 80: 117- 132
5. Noonan G J, Rand J S, Priest J, Ainscow J, Blackshaw J K 1994 Behavioural observations of piglets undergoing tail docking, teeth clipping and ear notching. Applied Animal Behaviour Science 39: 203- 213
6. Norring M, Valros A, Munksgaard L, Puumala M, Kaustell K O, Saloniemi H 2006 The development of skin, claw and teat lesions in sows and piglets in farrowing crates with two concrete flooring materials. Acta Agriculturae Scand Section A 56: 148- 154
7. South African Pork Producers’ Organisation with the Assistance of the Pig Veterinary Society 2011 The South African Code for the Welfare of Pigs.
8. Sutherland M A, Davis B L, Brooks T A, McGlone J J 2010 Physiology and behavior of pigs before and after castration: effects of two topical anesthetics. Animal 4, 12: 2071- 2079
9. Taylor A A, Weary D M 2000 Vocal responses of piglets to castration: identifying procedural sources of pain. Applied Animal Behaviour Science 70: 17- 26
10.  Taylor A A, Weary D M, Lessard M, Braithwaite L 2001 Behavioural responses of piglets to castration: the effect of piglet age. Applied Animal Behaviour Science 73: 35- 43
11.  Von Borell E, Baumgartner J, Giersing M, Jäggin N, Prunier A, Tuyttens F A M, Edwards S A 2009 Animal welfare implications of surgical castration and its alternatives in pigs. Animal 3, 11: 1488- 1496
12. Wallenbeck A, Gustafson G, Rydhmer L 2009 Sow performance and maternal behaviour in organic and conventional herds. Acta Agriculturae Scand Section A 59: 181- 191
13. Zonderland J J 2010 Talking tails: quantifying the development of tail biting in pigs. Thesis, Wageningen University

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