Pig welfare guidance

Guidance about the needs of pigs and how to meet these needs in accordance with good practice.

Monitoring animal health and welfare

Animal-based measures

51. Many recognised welfare standards are based on “inputs”, such as daily management duties and husbandry procedures or resources provided by owners / keepers to the animals such as housing, feed and water. Many of these inputs are defined as minimum standards in law and are covered throughout this guidance. However, certain animal-based measures can help provide a better understanding of how these inputs directly affect individual pigs and the herd as a whole. This in turn should focus owners / keepers, the veterinary surgeon and other expert advisors connected with the farm unit, in addressing the key issues in a particular pig herd. Validated on-farm welfare assessment protocols are already being widely applied in the pig industry and can provide information and guidance on the measures and assessment approach.

52. Any animal-based measures which are monitored and recorded should be practical and easily measurable, indicate the wellbeing of the pigs and provide potentially useful information for farm managers and veterinary surgeons. Some measures should be familiar, such as body condition, lameness and on-farm mortality.

53. Other factors may also be recorded and reported depending on the circumstances. These might include:

  • cleanliness of pigs;
  • tear staining;
  • expression of play behaviour;
  • interaction with enrichment materials (Lack of use of enrichment materials by the pigs may indicate the materials provided, and / or the way in which they are being provided, are not meeting the intended purpose);
  • evidence that aspects of the environment are causing injury and / or discomfort (such as pressure sores, occurrence of similar injuries on several animals);
  • evidence of fighting such as body marks and injuries on specific body parts (for example ears or tails); or
  • tail posture (tucked tails may be a concern).

Where there is a gradation of severity, for example minimal to mild or severe tail-biting, then simple scoring systems that all staff can consistently record in the same way should be considered.

54. Routine animal-based measures should be identified for all farm units / premises and should be agreed with a veterinary surgeon. There may be additional requirements specified through independent assurance schemes and supply contracts with which a veterinary surgeon and / or scheme advisor can provide assistance. Agreed measures should be accurately recorded at suitable intervals, following the advice of the farm’s veterinary surgeon. All owners / keepers should be clear about their responsibilities in accurate recording. Additional information from market sales and slaughterhouses may give further information on the health and welfare of the pigs. A number of the more common examples of animal-based measures are included in the following paragraphs. (Measures in relation to tail biting are discussed in more detail in the tail biting section – paragraphs 137 to 156) It may be useful to consider the installation and use of technology (such as motion sensors, CCTV) for on-going monitoring and assessment of pig welfare.

Fighting and aggressive behaviours

Paragraph 8 of schedule 6 of the Welfare of Farmed Animals (Scotland) Regulations 2010 states that:

8.—(1) If pigs are kept together, measures must be taken to prevent fighting which goes beyond normal behaviour.

(2) Pigs which show persistent aggression towards others or are victims of such aggression must be isolated or kept separate from the group.

55. Although fighting is a natural behaviour, minimising aggression between pigs should have production benefits, in addition to improving their welfare. While some wounds may be caused by poor pen or equipment design (see paragraphs 80 to 87), others will be caused by aggressive interactions. Body marks / scratches on different areas of pigs can help indicate different causes of aggressive interaction between pigs.

56. Aggressive interactions, fear and the wounds associated with fighting result in poor welfare for the pigs affected. Aggression between groups of pigs, including sows and boars, can be precipitated by a number of factors. For example, as soon as new pigs are introduced to, or removed from, a group this will affect the hierarchy and social structure of the group, leading to some fighting to establish a new ranking order. Management strategies which minimise regrouping will help to avoid this. Where regrouping is necessary, the new group should be closely monitored, and prompt action taken to separate pigs if severe aggression and wounding occurs. The use of products sprayed into the air to mask the odours that distinguish pigs from different groups may be considered. Persistent aggressors must be kept separate from the group (although ideally not totally isolated) and pigs with serious injuries must be removed to a hospital pen for treatment and recovery or be humanely killed as soon as possible. See also paragraphs 193 to 195.

57. Aggression can also occur due to competition over access to feed or water. There should, therefore, be sufficient access to both feed and water for the number of pigs in each pen. See paragraphs 118 to 128.

58. Energy expended during aggressive activities, and the healing from wounds as a result, can lead to a reduction in productivity for all pigs (including the aggressor) and thus poorer feed conversion rates. Any injury also carries the risk of infection with further negative impact on welfare and productivity.

Body condition assessment

59. Body condition scoring (BCS) is a key measure of the health and welfare state of a pig. Condition scoring is a simple technique for all pig owners / keepers to carry out that allows the body reserves (i.e. muscle and fat cover) of individual pigs to be assessed and enables better monitoring and adjustment of feed and management practices. Pigs can be assessed to ensure they are not too fat or too thin and sows and gilts can be properly managed throughout their breeding cycle. Keepers should be familiar with this technique, and should know the expected BCS at different stages of growth and physiological states. Keepers should be competent in these assessments and should understand when to carry them out. Advice on BCS should be sought from a veterinary surgeon, if required. Alternatives to BCS are available, and may be recommended by veterinary surgeons, depending on the particular circumstances of the unit.

60. Evidence of poor body condition, despite adjusting feed levels, may suggest disease challenge, nutritional or water issues, or behavioural problems that need further investigation. In any case where there is unexplained poor body condition, veterinary advice should be sought. There should be a clear protocol for managing chronic, poorly conditioned pigs in the herd, including euthanasia. It is poor practice to move these pigs into groups of younger animals as they could spread disease.

Lameness and limb lesions

61. Lameness is the inability to use one or more limbs in a normal manner, and can vary in severity from reduced ability or inability to bear weight, to complete inability to stand. Lameness or limb injury / lesion in any animal is usually a sign that they are in pain. It can also negatively affect productivity of growing and breeding pigs, particularly if appetite or access to the feeder is reduced. Replacement gilts should be carefully monitored for lameness as the quality and quantity of nutrition at certain stages of growth can significantly affect the incidence of lameness in replacement breeding stock. Lesions such as shoulder sores, foot lesions, or pressure sores on other parts of the limb may also indicate the need for nutritional or environmental improvements.

62. It is important that lameness and limb lesions are accurately recorded in accordance with veterinary advice, noting both the age of the pig(s), type of lesion or severity of lameness, and pen location of affected animals. Checks should be made of claw length and for any joint swellings. If a significant percentage of pigs in a herd are affected, the cause should be investigated and veterinary advice should be sought promptly and the problems addressed.

63. If a lame animal does not respond to treatment following veterinary advice, they must not be left to suffer, and should instead be humanely killed on farm as soon as possible. See paragraphs 69 to 72.

Managing sick and injured animals

Paragraphs 5 and 6 of schedule 1 of the Welfare of Farmed Animals (Scotland) Regulations 2010 state that:

5. Any animals which appear to be ill or injured—

(a) must be cared for appropriately without delay; and

(b) where they do not respond to such care, veterinary advice must be obtained as soon as reasonably practicable.

6. Where necessary, sick or injured animals must be isolated in suitable accommodation with, where appropriate, dry comfortable bedding.

64. Immediate action must be taken if any pigs appear to be ill or injured. A veterinary surgeon should be consulted if there are any doubts about the cause of the ill health or the most effective treatment, including appropriate pain relief. It is important to regularly review an individual pig’s response to treatment and if the pig is not improving, a veterinary surgeon’s advice must be sought as soon as possible. Where appropriate, the owner / keeper must ensure the pig is humanely killed.

65. Any health and welfare plan should specify a procedure for separating and caring for sick or injured animals. Hospital pens should be available for each category of pig on the unit and should be easily reached. The animals in them should be regularly checked throughout the day and a note of their condition kept as appropriate. Ideally, sick or injured animals should not be completely isolated as individuals but should still be able to see, hear or smell other pigs. When moving sick or injured pigs to the hospital pens, owners / keepers must ensure that unnecessary suffering does not occur. Unless specifically advised otherwise by a veterinary surgeon, drinking water must be continuously available along with feeding facilities which can easily be accessed by all pigs in the hospital pen.

66. Lame or recumbent animals should be well bedded with a sufficient depth of straw or similar bedding to avoid pressure sores developing. The use of rubber matting as an alternative can also be considered. Particular care is needed where recumbent animals are isolated to ensure that they can be checked and are seen to be consuming any feed and water provided.

67. Animals should be temporarily identified at the time of treatment, so that any medical treatments can be recorded against the individual animal and the time in the hospital pen can be monitored. Protocols for decision-making on euthanasia, particularly for recumbent pigs, should be established. If an animal does not respond to treatment and is unfit to transport, they should be humanely killed on-farm. Any animals suffering from painful and incurable conditions must be killed as soon as possible. See paragraphs 69 to 72.

Retained Council regulation (EC) No 1/2005, Annex I technical rules, Chapter I, Fitness for transport states:

1. No animal shall be transported unless it is fit for the intended journey, and all animals shall be transported in conditions guaranteed not to cause them injury or unnecessary suffering.

2. Animals that are injured or that present physiological weaknesses or pathological processes shall not be considered fit for transport and in particular if:

(a) they are unable to move independently without pain or to walk unassisted;

(b) they present a severe open wound, or prolapse;

(c) they are pregnant females for whom 90 % or more of the expected gestation period has already passed, or females who have given birth in the previous week;

(d) they are new-born mammals in which the navel has not completely healed;

(e) they are pigs of less than three weeks, […..], unless they are transported less than 100 km;


3. However, sick or injured animals may be considered fit for transport if they are:

(a) slightly injured or ill and transport would not cause additional suffering; in cases of doubt, veterinary advice shall be sought;

(b) transported for the purposes of the Animals (Scientific Procedures) Act 1986 if the illness or injury is part of a research programme;

(c) transported under veterinary supervision for or following veterinary treatment or diagnosis. However, such transport shall be permitted only where no unnecessary suffering or ill treatment is caused to the animals concerned;

(d) animals that have been submitted to veterinary procedures in relation to farming practices such as dehorning or castration, provided that wounds have completely healed.


68. There are strict legal requirements associated with the transport of slightly injured or ill animals. For example, pigs that are unable to walk independently without pain and those that have a severe open wound or prolapse are unfit to transport. An animal must not be transported unless it is fit for the intended journey, and should be healthy enough to tolerate the entire journey it is about to make (including loading, unloading and any other journey breaks). Sick or injured animals may be considered fit for transport if they are slightly injured or ill and transport would not cause additional suffering: in cases of doubt, veterinary advice should be sought. It is important that the welfare needs of animals continue to be met up to and during transportation. See also paragraphs 41, 63 and Annex 3.

On-farm killing

69. Any health and welfare plan should detail the approved methods to be used for killing animals and who is competent to do this. It should also set out details of contingency procedures in the event such persons are unavailable, such as obtaining a licensed slaughterer or a veterinary surgeon to carry out this procedure as soon as possible. Useful guidance on on-farm killing can be found on the Humane Slaughter Association’s website - see Annex 3.

It is an offence under regulation 22(1)(c) of the Welfare of Animals at the Time of Killing (Scotland) Regulations 2012 to contravene certain provisions of the EC Regulation 1099/2009, which are specified in schedule 2. Article 3(1) of this Regulation states that:

Article 3

1. Animals shall be spared any avoidable pain, distress or suffering during their killing and related operations.

This general offence applies in all cases, but the more detailed provisions in respect of the method of slaughter or killing in EC Regulation 1099/2009 do not apply to killing of animals which are injured or have a disease associated with severe pain or suffering and where there is no other practical possibility to alleviate this pain or suffering.

70. Animals must be killed humanely using a method which immediately renders them unconscious until death. A percussive blow to the head may be used to kill piglets up to 5kg in Scotland where no other method is available. This may be a manual percussive blow by a trained and competent operator, however where possible a mechanical non-penetrative captive bolt device should be used in accordance with guidance issued by HSA in March 2022. In heavier pigs, a penetrative captive bolt device with a suitable strength cartridge may be used as a simple stun and must be immediately followed by bleeding or pithing to kill the pig. Other legal methods include an accurately placed shot to the head from a firearm of appropriate calibre with a free projectile of sufficient power to kill the pig. Operators should be trained and competent in the method used and equipment should be properly maintained. Methods to be used should be agreed with the farm’s veterinary surgeon.

71. Where a pig has to be killed in an emergency, that is where the pig is injured or has a disease associated with severe pain or suffering that cannot be practically alleviated, then any method of killing is allowed as long as:

  • the animal is killed humanely;
  • the animal is spared any avoidable pain, distress and suffering;
  • the animal is killed as soon as possible;
  • the procedure is carried out by someone who is suitably trained and competent in the killing method to be used and in the use of the equipment; and
  • checks are made by the above person to ensure that there is no sign of life.

Under these emergency circumstances, a certificate of competence is not required, although it is desirable.

72. After a pig’s death or killing, the carcase must be transported for disposal by a suitable method without delay (see Annex 3 for further guidance) and the death recorded in the holding register. While awaiting disposal, the carcase must be stored in a covered, leak-proof container which should be locked and inaccessible to domestic animals and wildlife. The products of farrowing, stillborn pigs, foetuses and after-birth (placentas) are all animal by-products covered by legislation. See Annex 3.


Email: animal_health_welfare@gov.scot

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