Farm Ireland

Sunday 17 December 2017

To castrate or not -- that is the question

Michael Gottstein

Now that the new season lambs are being born on farms, the annual debate regarding the castration of male lambs arrives.

In my day-to-day work it is a question that I come across frequently -- so let's have a look at the facts.

Growth rate

Entire males grow quicker. That holds true for sheep in the same way as it does for cattle.

Trials carried out at Teagasc in Athenry have shown that lambs left entire were 1.8kg heavier at weaning, produced leaner carcasses and were slaughtered 16 days earlier than lambs that were castrated at birth. See table 1


However, despite the additional growth rate, entire male lambs will have to be managed as a separate flock away from ewe lambs post-weaning.

Where this practice is not carried out, the benefits of the extra growth rate are quickly foregone as the ram lambs will spend most of their time chasing ewe lambs.

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In addition to this, only lambs that are likely to make it to slaughter by late August are potential candidates for being left entire.


It is important to recognise what type of produce the market wants.

There is little point in producing your lambs and then having trouble finding a market for them.

In general, the specifications for lambs destined for the home market (butchers/supermarkets) require that male lambs are castrated.

The reason for this is the perception that meat from ram lambs has a stronger or gamey flavour. And regardless of what sheep producers feel in this regard, in marketing, perception is reality and the consumer is king.

On the other hand, there are a few niche markets that have developed over the past few years where entire ram lambs have been in demand (for religious festivals such as Ramadan, etc).

In these situations, having a supply of suitable lambs available can pay dividends.

It is, however, important that these markets are only niche markets for short periods of time and that our ability to supply them is very much dependent on issues such as our disease-free status (blue tongue, FMD etc) and suitable weather for shipping.

Legal/Quality Assurance


Castration may only be carried out by the farmer using a rubber ring -- provided it is done within the first week of the lamb's life.

Castration after this age may only be carried out using the Burdizzo method, which may only be done up to three months.


Entire lambs grow faster, have leaner carcasses and finish earlier. On farms where high levels of lamb growth rate are consistently achieved and ram lambs are separated from ewe lambs post-weaning, there is a benefit in not castrating male lambs destined for slaughter before the end of August.

Before embarking on this road make sure that your market outlet is happy to take ram lambs.

Targeting ram lambs for niche markets later on in the year is something that each producer needs to consider for themselves.

It is important to recognise that these are only niche markets for relatively small numbers of sheep for a short period of time.

In addition, there is also a potential risk that a disease outbreak or bad weather could disrupt this trade.

Given that over 60pc of mid-season born lambs are killed after the end of August each year, the majority of producers should consider castrating lambs to simplify management at farm level and to ensure that lambs meet market specifications.

Irish Independent