The best time to castrate a pig is when it is 1 to 21 days old. This is because piglets are easier to castrate and there are unique benefits to the animal that can only be had when castration is performed early on.

The American Veterinary Medical Association’s (AVMA), however, who are more concerned with striking just the right balance between animal welfare and efficiently producing quality pork, recommends castration be performed later

The AMVA state that castration should be performed at least 5 days prior to weaning to allow for sufficient healing before pigs are removed from the sow. Additionally, if castration is performed when a pig is beyond 28 days of age, anesthesia or analgesia should be used.

Why Castrate Pigs?

There are a few very important reasons why it’s common practice to castrate pigs and why many believe that castrating pigs is necessary.

  • Castration can reduce “tainting” of the flesh, which causes an odor and flavor problem when pork is cooked. Considering that 75% of consumers find meat from boars objectionable in comparison with meat from castrated males (barrows), this is the most important reason for castration.
  • Castrated pigs can safely be kept with sows without the risk of unwanted litters
  • Castration can reduce aggression in boars and in those breeds bred for meat

Pros & Cons of Castrating Early

Castrating pigs early on is preferred for a few reasons. Very young pigs are easier to hold or restrain, bleed less, and may have antibody protection from the sow’s colostrum, which helps prevent infection and promotes fast healing.

The main disadvantage of castrating pigs so early on is that scrotal hernias are more difficult to detect. If these herniated pigs are unknowingly kept for breeding, it can be costly to the farmer.

Can It Ever Be Too Late to Castrate a Pig?

While there isn’t necessarily a time where it is too late to castrate a pig, if you delay castration it becomes much more difficult for the procedure to go smoothly. Older pigs will be more aggressive and a lot more challenging to hold and restrain. They will also bleed more. You will save yourself a lot of unnecessary hassle if you castrate early on.

Methods of Castration

Two methods are used to castrate pigs: surgical castration and immunocastration. Surgical castration of pigs is the far more common of the two.

Surgical Castration

Surgical castration is most commonly carried out prior to weaning and performed without anesthesia or analgesia because it delivers the best results in regard to profitability, performance and reduction of boar taint.

No surgical procedure is 100% safe – and surgically castrating pigs is no exception. Complications including hemorrhage, excessive swelling or edema, infection, poor wound healing, and failure to remove both testicles can all occur. Surgically castrated barrows may also suffer from suppressed immunity and exhibit higher incidences of inflammation, pneumonia and other diseases.

Surgical castration involves a four-step process.

1. Make sure that you have the proper equipment

  • Scalpel handle and blade
  • Paper towel or other wipe
  • Disinfectant for equipment

2. Handle the piglet correctly

  • Grab the piglet by its back legs
  • Hold the piglet in an upside down position
  • With your thumb, push the testicles into the scrotum and keep them there

3. Take a closer look at the testicles

  • Look at the scrotum to make sure 2 testicles can be seen
  • Feel the testicles to see if they are both the same size and firmness
  • Ensure that both testicles are freely movable

4. Perform castration

  • Make an incision over each testicle
  • With your fingers or some other instrument, apply pressure behind each testicle and push each testicle out of the hole made with the blade
  • With your hand or some other instrument, grasp each testicle and pull it
  • Make sure each testicle and the entirety of its attached cord is removed
  • Leave the incisions open and spray with iodine


Immunocastration is a temporary form of castration but is still able to reduce sexual and aggressive behaviors in male pigs, as well as adequately reduce boar taint.

Immunocastration involves an injection of a protein compound to induce antibody production against gonadotropin-releasing hormone (GnRH). Two injections are required.

The first injection is given in the first 8 to 11 weeks prior to slaughter, and the second injection is given 4 weeks prior to slaughter.

One reason why immunocastration might be used over surgical castration is that immunocastrated males have higher growth and lower feed conversion rates than physically castrated males.