Does Age of Castration Affect Daily Weight Gain in Beef Cattle?

This week, by popular demand, we have an article for our farmers.  Castration is a relatively common procedure involving beef cattle in many parts of the world, including our own.  Castration is performed mainly to control breeding and reduce fighting in the herd.  Another useful outcome is that the reduction in aggression of the animal will likely reduce farmer deaths.  This point is particularly important as at present we lose 12 farmers per year to on-farm accidents in N. Ireland.

        There are three main methods of castration – rubber banding, burdizzo (squeezing) and surgical.  All are carried out with anaesthesia and pain relief.  We can examine the pros and cons of each technique another time, but in this article I want to examine the effect of age of castration on weight-gain of the animal.

Traditionally farmers have waited until a bull is older than six months before performing this procedure.  This can produce challenges for both farmer and vet, as the animal is more difficult to handle.  Research has been undertaken examining the effect on weight gain of animals both older and younger than six months*.  The first interesting finding from this research is that weight loss increased by a factor of 4 as the age of castration increased.  This means that the younger the animal is at age of castration the less the effect on weight loss.  E.g. rubber banding under six months will be more beneficial to the animal than surgical castration over six months.  To put this another way, it costs a lot more in food to feed animals that are castrated older because they lose a lot more weight as a result of the procedure, no matter which technique is used.

The second interesting finding was that the stress response in animals castrated < 6 months of age was lower than those castrated  > 6 months of age.  This should be of interest to anyone involved in animal husbandry as we are all aiming to improve the welfare of animals under our care.  Finally rubber banding seemed to be gentler than the other methods.

So, both anecdotally and with research to back it up, it would seem that carrying out castration early on is both nicer for the animal and safer for the farmer.

*References available on request