What are some of the painful procedures experienced by sheep on farm?

RSPCA defines a painful farm animal husbandry procedure as any action that alters or removes a specific body part of a farm animal and causes pain, suffering or distress. Any procedure that results in tissue injury should be assumed to cause pain, and therefore must be approached accordingly. RSPCA acknowledges that painful husbandry procedures are routinely carried out across many farming systems. However, the aim for all future farming systems must be to identify and adopt humane husbandry and management practices that do not cause pain, suffering or distress to animals. In the interim, best practice pain relief must be used.

Routine husbandry practices

Routine husbandry practices carried out on sheep include non-invasive procedures such as shearing of the whole body or to remove faecal pads (dags) or wool from the perianal region (referred to as ‘crutching’), as well as backlining, dipping or jetting with insecticides (to prevent lice), oral drenching with anthelmintics (to prevent parasites), mouthing, feet inspection and vaccination. These procedures may cause stress to the animal but are not painful (unless rough handling or injury occurs).

Invasive and painful procedures may include tail docking, castration, and mulesing carried out at lamb marking, and, later in life, surgical artificial insemination of some ewes for reproduction. Many of these procedures elicit pain and inflammatory responses [1]. Pain displays in sheep may include head turning, foot stamping, lying on their side, rolling and writhing, restlessness and statue standing.

Prior to performing a painful procedure on farm, proper consideration must be given to the following:

1. Removal: If the procedure is not justified, stop using the procedure
2. Alternatives: Replace the procedure with a painless or less painful alternative
3. Breeding/genetics: Where possible, rear animals that no longer require the use of such procedures (i.e., select for positive welfare traits when breeding)
4. Modify: Improve the procedure in order to minimise pain intensity and/or duration
5. Treatment: Pain amelioration or prevention using anaesthesia and analgesia [2, 3]

Overview of painful procedures

Tail docking

The main reason for tail docking sheep is to reduce the risk of flystrike by minimising the opportunity for urine and faeces to soil the breech area (upper hindquarters).

Tail docking is routinely performed on young lambs using a rubber ring, sharp knife, or docking iron. Tail docking of lambs should only be carried out as a part of a planned strategy to reduce flystrike in wool-producing sheep. Lambs that are killed at an early age, e.g., for meat production, should not be tail docked. If the procedure is deemed necessary, it should be performed on juvenile lambs in their first weeks of life and should be accompanied by local anaesthetic and pre- and post- analgesic administration. Research suggests that hot-iron cauterisation is the least painful method. The length of the docked tail must at least cover the vulva in female lambs and the anus in male lambs. Some sheep have naturally short tails and so breeding for such traits is the most desirable opportunity for removing the need for this painful procedure [4].

Mulesing

Mulesing is the use of shears to cut away wool-bearing skin from part of the tail and breech area of sheep used for wool production and is performed to reduce the incidence of flystrike in the breech area. It is unacceptable to continue to breed sheep that are susceptible to flystrike and therefore require mulesing or other painful procedure to manage flystrike risk. For more information on and RSPCA’s position on mulesing sheep, read here.

Castration

Male lambs are routinely castrated to prevent unwanted breeding, reduce aggression and sexual behaviour, as well as minimise the risk of injury to the animal, other animals and animal handlers. Castrated males may also produce preferred meat and carcass quality traits compared to non-castrated males.

The most common methods of castration include using a rubber ring or cutting using a knife or blade. Castration of sheep using a hormone-based vaccine program may be a viable option in the future [5–9]. Studies assessing pain behaviours demonstrated that rubber ring castration (along with ring tail docking) causes more pain than surgical (knife) castration in the period following the procedure, and other studies have shown that knife castration results in acute pain. As such, it is recommended that both acute and inflammatory pain need to be addressed, regardless of the mode of the procedure, via the use of local anaesthetic and pain relief [10].

Laparoscopic artificial insemination and embryo transfer

Artificial insemination via laparoscopy is an invasive surgical procedure performed on small ruminants including both sheep and goats. It is mainly carried out by stud breeders to increase the number of offspring from rams than would be possible from natural matings.

The procedure involves penetration of the abdominal cavity and deposition of semen directly into the uterine horn of a fertile female. Gas is also inserted into the abdominal cavity so that the person performing the procedure can better view the reproductive tract. The procedure results in high pregnancy rates and efficient semen use, however it is invasive and requires specialised equipment and surgical expertise. Non-surgical methods are challenging in sheep due to the anatomy of their cervix making it difficult for insemination to occur. Penetration of the abdominal cavity causes pain and results in inflammation (caused by tissue damage) and distress. The procedure should be undertaken by highly skilled technicians or veterinarians with appropriate analgesic, anaesthetic and sedation. Minimising stress and discomfort should be priority, as well as surgical speed and efficiency to reduce the risk of complications. An additional concern with the procedure is that it requires the use of a hormone (Pregnant Mare Serum Gonadotropin, or PMSG) to stimulate the ewe to cycle and be receptive to the ram (or in this case, the AI). This hormone is produced from the blood collected from pregnant mares farmed for this purpose. The condition and treatment of horses on these farms is a serious animal welfare concern [e.g., 11] and the use of PMSG must be urgently replaced with synthetic alternatives.

Embryo transfer is carried out as a means of producing a greater number of genetically improved offspring than can be achieved through conventional breeding. The procedure involves the collection of embryos via laparoscopy from ewes with desirable genetic traits (donor ewes) to recipient ewes. Methods for embryo transfer require surgical penetration of the abdominal cavity and flushing of the oviducts. The collected embryos are then surgically transferred into the recipient ewe. Non-surgical methods are emerging, however as previously stated, due to the sheep’s anatomy, passing a catheter through the cervix is difficult [12].

Competency and animal handling

All people handling sheep and/or performing painful procedures must be appropriately trained and able to competently undertake their required tasks. Sheep must be handled calmly and quietly, always using principles of low-stress handling [13]. If young animals are separated from their mothers to perform a procedure, they should be returned as soon as possible to minimise stress. Before commencing a painful procedure, sheep must be restrained in a manner that is appropriate to the age and size of the animal, as well as to the procedure being performed. The restraint method must be as quick as possible, avoid pain and minimise stress to the animal. Personnel must have the ability to recognise and address signs of pain, suffering or distress. Contingency plans must be in place and adhered to should euthanasia or emergency veterinary care be required [13, 14].

What is the RSPCA’s view?

Before performing any painful procedure, proper consideration must be given to alternatives that could eliminate the need for the procedure in the first place. Where it is considered necessary to undertake a painful procedure, it must be done at the earliest possible age. All procedures must be performed by trained, highly skilled and competent operators. Pain relief using appropriate analgesics and anaesthetics must be provided. Current best practice pain relief for procedures such as castration, tail docking and mulesing include local anaesthetic in combination with a non-steroidal anti-inflammatory drug. Research priorities should be aimed at progressing alternatives to painful invasive procedures (e.g., breeding for select traits that remove the need for certain procedures to be undertaken) as well as urgent development of technologies that provide longer-lasting pain relief.