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Leaving rams entire
You do not need to routinely castrate ram lambs and many are left entire. Explore the advantages and disadvantages of this option, including the impact on productivity and profitability.
Advantages of leaving rams entire:
- Increased daily liveweight gain
- Improved feed conversion efficiency – no difference in feed intake for wethers (castrated rams) and rams
- Leaner carcases
- Animals reach slaughter weight earlier
- Animals are not exposed to painful procedures
- Potential to reduce greenhouse gas (GHG) emissions
- No direct costs
Disadvantages of leaving rams entire:
- Frustration and fighting between males
- Potential unwanted pregnancies
- Need to manage ram lambs separately post-weaning
- Possible additional indirect costs, such as fencing and labour
- Possible penalties for entire ram lambs at slaughter over certain ages
Table 1. The impact of leaving ram lambs entire
| Measure | Rating |
|---|---|
| Cost | £ |
| Speed | Fast |
| Production system | All |
£ No new equipment or time constraints over and above existing business-as-usual running costs
Where can this practice work?
Leaving ram lambs entire can work in a variety of systems, provided the appropriate management procedures, infrastructure and land are available to manage ewes and entire ram lambs separately.
It is particularly suitable for systems which aim to sell lambs finished before sexual maturity is reached, such as lowland systems that achieve high performance at grass and aim to sell lambs before weaning.
You may choose to leave single and larger twin lambs that are born early in the lambing season entire and castrate smaller males and lambs born later. It can also be suitable if there is sufficient land available to manage ewe lambs and ram lambs separately post-weaning.
It is generally advised to separate lambs at weaning, or by 20 weeks of age at the latest.
Take care with very early maturing breeds, such as Poll Dorsets, as sexual maturity may be reached before 14 weeks of age. In these cases, it would be prudent to wean lambs by 12 weeks of age.
How much does leaving rams entire cost?
There are no direct costs associated with leaving rams entire, with savings made from consumables and the labour associated with castrating lambs.
However, the management of entire ram lambs is likely to incur indirect costs, such as the establishment and/or maintenance of adequate fencing and additional labour costs. These expenses are hard to define as they will vary from farm to farm.
How can leaving rams entire be done well?
You need a plan that reflects the time of year that you intend on marketing your lambs. This will ensure you can manage entire males separately and/or that you send them to slaughter before they reach sexual maturity.
As a contingency, make sure you have enough space and suitable fencing to separate entire males from ewes, should they reach sexual maturity earlier than expected.
From a welfare perspective, it is generally considered good practice to finish entire lambs as quickly as possible. This will also improve meat quality and reduce feed costs.
If you are not planning to castrate your rams, you need to consider when different breeds reach sexual maturity.
Early maturing breeds, e.g. Hampshire Down, Dorset, Suffolk and Charollais, have high potential growth rates and would benefit from being left entire.
Where Estimated Breeding Values (EBVs) are available, you can select rams that are likely to produce lambs that grow quickly and reach finished condition at a younger age. This would result in more male lambs reaching sale weight before sexual maturity and reduce the need for castration. However, it is important to make sure that increasing growth rates does not have a negative impact on animal welfare.
The Animal Welfare Committee report (2022) highlights the need to manage the selection for growth rate carefully to reduce the risk of increased lambing difficulties (dystocia), reduced fertility and potential health issues that have been seen in other species.
Check whether the markets you supply will penalise you for presenting entire lambs. This is more likely to be an issue with older lambs, and processors/retailers may issue a ban on entire ram lambs after a particular date – this could be as early as October, although it will vary between processors/retailers, and continue until new-season lamb the following year.
Some markets prefer older entire ram lambs, which provides marketing opportunities. The Muslim festival of Eid al-Adha requires the act of Qurbani (Urdu) or Udhiyah (Arabic), which is the slaughter of an animal as thanksgiving. For an animal to be used for Qurbani, it needs to meet specific age requirements and be sexually mature; in general, entire lambs over six months are acceptable.
What is the impact on animal welfare?
Uncastrated lambs are not exposed to potentially painful procedures that could have an impact on their freedom from pain, injury and disease, their freedom from discomfort and their freedom to express more normal behaviours.
However, it could also result in frustration, fighting and unplanned pregnancies.
What is the impact on productivity?
Keeping rams entire improves daily liveweight gain and feed conversion efficiency. It also results in leaner carcases.
One study found no difference in feed intake between wethers and rams, which suggests that entire males have improved feed conversion efficiency.
Another study showed the combination of higher growth rates and improved feed conversion could result in early crossbred lambs achieving higher slaughter weights (an extra 2–3 kg liveweight) or reaching slaughter condition up to 10 days earlier. In creep-fed systems, this results in significant savings.
What is the impact on profitability?
Evidence of the impact on meat quality is mixed. Some studies suggest the meat quality of ram lambs is inferior to that of castrated lambs, negatively impacting profitability.
Other research shows that age of slaughter can influence the taste and quality of lamb meat, with meat from entire lambs slaughtered before reaching sexual maturity showing no quality differences to that from castrated lambs.
Meat from entire males contains less saturated fat, less loin fat and less leg fat, which is more appealing to many consumers. Research is mixed on whether a lower fat percentage impacts carcase weight and carcase grade.
The financial impact of castration versus leaving ram lambs entire is variable. If you can take advantage of the superior growth rates and improved feed conversion, while meeting market requirements, leaving rams entire could be a profitable option.
However, profitability of entire males sold later in the season is highly dependent on feed costs and whether your market will penalise you.
What is the impact on environmental sustainability?
When we conducted this research, we did not find any studies investigating the direct environmental impact of leaving lambs entire. However, faster growth rates, better feed conversion and potential feed savings will improve the efficiency of your flock and potentially reduce greenhouse gas (GHG) emissions.
What are the legal implications of leaving rams entire?
Section 4 of the Animal Welfare Act 2006 states that any suffering an animal endures must be out of necessity, such as for the benefit of the animal, the safety of other animals or protection of people and property. This puts a legal onus on producers and other responsible individuals to avoid castration unless there is a legitimate reason for doing so.
There are also legal considerations further along the production cycle. Council Regulation (EC) No 1/2005 states that sexually mature male and female animals may not be transported together.
You therefore need to consider the logistics and potential adaptions required to keep entire ram lambs.
How do farm assurance schemes manage leaving rams entire?
The RSPCA standards aim to phase out castration altogether, although a timeframe for this is not given.
Many standards also include requirements beyond those in law for transport of animals. For example, Red Tractor does not permit sexually mature entire males to be transported with other males they are unfamiliar with. These restrictions could impact the logistics for some producers at the end of the finishing period.
How the three Rs can be applied
We have reviewed leaving ram lambs entire and various castration methods in terms of how they can be reduced, refined or replaced (the three Rs) and the impacts of doing so.
Strategies for reduction: Leaving male lambs entire has a low risk of adverse effects on animal welfare. As such, there is no scope to reduce the number of lambs that are kept entire.
Strategies for refinement: Make or update your contingency plan to mitigate any potential disruptions with getting lambs off farm. Monitor growth rates and make sure you have enough space and resources to minimise issues should lambs reach sexual maturity before leaving the farm.
Strategies for replacement: Do not replace this practice with any castration method unless you are unable to meet the necessary management procedures, e.g. infrastructure, space and fencing. This decision should be made based on individual farm circumstances.
The information on this page is taken from an AHDB-commissioned report.