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Got big bull calves to castrate?

The ideal age to castrate male calves is a minimum of two and up to eight weeks of age.  The younger the better as this minimises pain and ensures a quick recovery with minimal loss in production.

However, we know that sometimes circumstances arise when you may find yourselves with big bull calves from time to time. So, what's the best way to go about this?

Know the Law

It is illegal to castrate calves greater than six months of age in NSW. Veterinary attention must be sought as animals at this age experience increased risk of:

  • post op infections
  • blood poisoning
  • severe pain
  • loss in production
  • even death.

Castration Methods (big calves)

Elastrator Rings (rubber rings)

A good rule of thumb is that if the traditional ring that you would normally use when they are two months of age or less doesn't fit their testicles, don't bother using a ring at all.

Large or extra-large size rings are not recommended as we have seen an increase in blood poisonings and deaths associated with using these.

Knife or Scalpel

When the testicles do not fit a traditional rubber ring, knife or scalpel castration is the preferred option in bigger sized calves and should be performed by an experienced operator.  Details on this method can be found in the online resources listed at the end of this article.

Bear in mind that knife castration leaves an open wound which can increase the risk of post-op infections.

A large incision at the bottom (base) of the scrotum reduces the risk of infection and swelling by maximising drainage. It is also critical that all animals receive a minimum of 5 in 1 vaccination to protect against tetanus and hygienic techniques must also be used (e.g. blades kept in disinfectant and replaced frequently). 

Burdizzos and Emasculators

Unlike knife or scalpel castration, use of burdizzos and emasculators offer the advantage of being bloodless (clamp off blood supply and associated spermatic cords).

However, animals must be adequately restrained as use of burdizzos and emasculators require precision and carefully timed application by an experienced operator.

Planning for recovery

Regardless of castration methods used, always perform castration in good weather as excess dust, heat and muddy conditions increase risk of post-op infection.

Additional use of prophylactic antibiotics and pain relief in big calves can minimise post-op infections, improve recovery time and overall performance. Talk to your veterinarian about use of veterinary drugs.

You want the calf to return to normal grazing behavior as quickly as possible. Visible signs of pain and distress include

  • kicking at site
  • tail swishing
  • restlessness
  • swelling
  • stiffness
  • lying down more than usual.

Further information

For further information, contact your veterinarian or your local district veterinarian.

Resources