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CONTRIBUTOR(S): Vetstream Ltd, Temple Grandin, Louise Cox-O'Shea,



Castration involves removing the testicles from a male animal. There are various techniques, some of which may be more suitable at certain ages. It’s a painful procedure and pain relief should always be given.

A dual-action emasculatome ©Ash Phipps

Why castrate?

Castration increases the value of the animal at point of sale and improves meat quality. It reduces aggression and removes the chance of unplanned/undesired pregnancies, and increases the options available for accommodating calves after they reach sexual maturity. Castration also generally means animals are safer to handle. Some producers may decide to not castrate, so as to get increased growth from bulls. In this situation, the abattoir will usually want bulls finished by 16 months. To avoid stress, finished bulls must be shipped together with their pen mates. Finishing bulls beyond 16 months reduces beef quality and also increases danger due to their sexual maturity.

Although a commonly performed procedure, castration does carry risks and there are potential complications. It is important that castration techniques are performed correctly so as to minimize complications and optimize animal welfare.

Consult your veterinary surgeon for further information.

When is the best time to castrate?

Animals can be castrated at various ages, but the earlier the better. Earlier castration is associated with reduced incidence of haemorrhage and infection, it has less of a negative impact on weight gain, and means easier handling and improved safety to both animals and handlers.

Under the Veterinary Surgeons Act 1966, only a veterinary surgeon may castrate a calf which has reached the age of 2 months (UK).

What are the methods of castration?

Castration rings

This method involves placing a rubber ring around the neck of the scrotum, hence cutting off blood supply to the area below the ring (testicles and scrotum). Over a period of weeks the testicles and scrotum will dry up and drop off.

DEFRA’s ‘Code of recommendation for the welfare of livestock’ states “A rubber ring or other device, can only be used in the first 7 days of life, by a trained and competent stock keeper, to restrict the flow of blood to the scrotum”.

  • Minimal equipment needed.
  • Minimal restraint needed.
  • Cheap.
  • Relatively simple method.
  • Painful.
  • If performed incorrectly, abscesses can form.
  • Sometimes only one testicle will be entrapped.
  • Risk of tetanus – as calves of this age will not usually have been vaccinated against tetanus.

Bloodless castration (Burdizzo/Emasculator)

Often used on older calves. This method works by crushing the spermatic cord and associated blood vessels. It must be done one side at a time.

  • Bloodless.
  • Minimal risk of fly strike.
  • Least risk of infection.
  • Painful.
  • Highest rate of failure of all the methods of castration.
  • Must be performed by an experienced person or veterinary surgeon.

Surgical castration

There are a number of different techniques. All methods involve incising the scrotum and removing both testicles (in their entirety) from the scrotum.

  • The most reliable method.
  • Less negative impact on growth rate.
  • High degree of restraint required.
  • Must be performed by a veterinary surgeon (increased cost).
  • Painful.
  • Risk of fly strike.
  • Risk of hemorrhage.
  • Risk of infection.

Other methods

Chemical castration is rarely used in cattle.

Consider the use of sexed semen to reduce the number of bull calves in the herd to reduce the number of animals requiring castration.

What medication is used?

Under the Protection of Animals (anaesthetics) Act 1954, it is an offense to castrate calves which have reached 2 months of age without the use of an anesthetic. Furthermore, the use of a rubber ring, or other device, to restrict the flow of blood to the scrotum, is only permitted without an anesthetic if the device is applied during the first week of life (UK)

Regardless of the legislation above, all methods of castration are likely to cause pain in any age of animal.  Appropriate anesthetic and analgesia shold always be provided.

The British Cattle Veterinary Society (BCVA) have stated that they believe that existing legislation does not reflect a level of appropriate analgesia and fails to reflect changes in scientific understanding, pharmaceutical developments and societal opinions which have developed over time.  The BCVA statement on analgesia can be accessed bu BCVA members at 

Rubber ring castration is most likely to cause chronic (long term) pain.  Recent work has indicated that young calves certainly do feel pain as much as any other age of calf and may in fact be more sensitive to pain.

Surgical castration is associated with the most acute (immediate) pain, but this can be mitigated by the use of analgesic agents.

Three main types of drug are used to control pain associated with castration procedures.

Local anaesthetics

  • Local anesthetics may be injected into the testicle and scrotal skin, prior to the procedure. Injecting the anaesthetic will be uncomfortable for the animal but after this they should not be able to feel the procedure itself.
  • The local anesthetic will provide pain relief for up to three hours (this varies with the product used). Therefore, the animal will need additional pain relief for when this local anesthetic has “worn off”.
  • Local anesthetic is not expensive.

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs (such as meloxicam and flunixin) reduce the pain and inflammation associated with castration for a longer period following the procedure. The period of effectiveness varies between products. By controlling pain in the post-operative period, animals are more likely to eat and drink well and thus minimize reductions in growth and productivity associated with castration.


Some animals may require sedation for castration. The most commonly used drug is Xylazine. Sedatives do often offer a degree of analgesia but this is minimal and so analgesics should also be used for sedated animals. The use of sedatives makes the procedure easier and less dangerous for the humans and the animal involved.

Discuss pain relief protocols with your vet to decide what is optimal for your animals.

What aftercare is needed?

Short-term aftercare

Following the application of rubber rings calves can show signs of acute pain – these animals should be monitored closely for a few hours after the procedure and advice sought from your veterinary surgeon if the pain is not controlled.

Following burdizzo castration animals should be checked for pain and swelling in the hours immediately after the procedure.

Following surgical castration the animals should be moved to a clean shed or pasture. The calves should be closely monitored for bleeding for 3-4 hours. If bleeding is suspected call your veterinarian immediately.

It is advisable to avoid castrating calves during fly season. Fly repellent should be applied around the area but not onto the surgical wound.

Your veterinarian may deem it necessary to use injectable antibiotics, this will be decided on a case by case basis.

Long-term aftercare

Rubber ring and burdizzo procedure
  • It usually takes several weeks for the testicles and scrotum to atrophy and drop away following rubber ring application. Hence it is important that animals are checked for several week after application.
  • Look for signs of pain and/or abscess formation.  If either is suspected contact your veterinarian immediately. An abscess may need to be surgically drained by your veterinarian and your veterinarian will need to advise you on medications required.
  • Tetanus should also be a consideration with the rubber ring technique, if suspected contact your veterinarian immediately.
  • Following both rubber ring castration and burdizzo castration the area should be checked for remnants of testicles in the following weeks/months. If remnants are suspected it is best to contact your veterinarian for surgical removal.
Surgical castration
  • In the weeks following surgical castration the area should be regularly checked for signs of infection or fly strike. If either occur contact your veterinarian.

What else do I need to know?

Adequate restraint is essential for the safety of both the calf and the person carrying out the castration procedure.

Calves should be castrated in a crush. If they are too small and the procedure is being carried out in a race, ensure the animal cannot back up by placing a metal bar behind them. If a scalpel blade is being used, make sure it is disposed of safely between animals.

If the calf is still with his mother be vigilant as to where the cow is. Cows can become aggressive when separated from their calves.

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