One of the main aims of the NI Sheep programme has been the importance of genetic improvement and breeding profitable sheep.

In order to achieve genetic improvement, accurate records are vital to assess what level of liveweight gain has been achieved over a set period of time.

Paper-based record keeping and electronic identification (EID) have been commonly practised by the programme farmers.

While some farmers have recently converted to EID, they are already utilising software packages to the full.

However, irrespective of the system, the importance of keeping accurate records, especially when it comes to selecting ewe lambs as flock replacements, cannot be over-emphasised.

Selecting ewe lambs

Some of the farmers have been selecting ewe lambs as flock replacements in recent weeks, despite the temptation to cash in animals with buoyant market prices.

The heaviest female lambs in June or July will be weaned from ewes with high milking ability, making them the ideal animals to breed replacements from.

Do not leave ewe lamb selection until later on in the year. The best maternal genetics in this year’s lambs may be sold by this time, or ewe lambs will struggle to hit breeding weight when going to the ram this autumn.

If you normally have a 25% replacement policy, then select 30% of your lamb crop as replacements.

This number can be reduced to those animals that display the most desirable growth figures and are also physically and visually correct for your system.

Selection on upland farms

Clement Lynch – Park, Co Derry

Clement runs 580 ewes, split between crossbred and Lanark-type Scottish Blackfaces. He operates a closed flock and only purchases rams with estimated breeding values (EBVs) where possible. Since 2015, he has been using an EID system to record flock performance and output, using this data to make informed decisions in relation to his replacements.

Around 90% of replacements are selected from liveweight gain records and ewes that produce twin lambs.

Clement Lynch has been using EID to select replacements since 2015.

Lambs are weighed at eight weeks old. From this weighing, ewe lambs that have above average growth rates for that year’s lamb crop are identified initially as potential replacements.

Recent weights have ranged from 18.1kg to 38kg for crossbred lambs with animals differing by one month in age from oldest to youngest.

Generally 80 crossbred, 50 Lanark and 30 Mule ewe lambs are kept initially from records. This is reduced to 150 following another draft later in summer.

No animals with terminal traits are kept. No replacements are kept from the crossbred flock if their daily liveweight gain is less than 300g/day.

Hill flock

In the hill flock, Clement believes there is an underlying fertility issue with the Lanark ewes which results in a smaller pool of suitable replacements to choose from.

Swaledale rams have been introduced to cross with Lanark ewes, as hybrid vigour should naturally improve ewe fertility and increase the size of the ewe lamb replacement pool.

Rams with five stars for maternal traits on the Sheep Ireland database are being used to produce replacements.

Once selected, ewe lambs are kept as a separate replacement batch so performance can be monitored more closely.

In the future, Clement is aiming to utilise the EID reader to capture information on mothering ability, milking ability, whether ewes lambed on their own etc.

Peter and Karol McCaughan – Ballycastle, Co Antrim

Brothers Peter and Karol run approximately 650 ewes consisting of crossbred and Lanark-type Scottish Blackface ewes.

Fertility in the flock has been an issue over a number of years, leaving them with a small pool of replacements to choose from, especially in the Lanark ewes grazing the hardest parts of the mountain.

Improvements are being made through OPA scanning and general ewe condition and flock health, lifting scanning figures up approximately 30% in 2022 compared to the previous year.

Up until last year, Peter and Karol were mainly using paper recording and then transferring onto spreadsheets.

In 2021 they invested in an EID unit and although they are still learning the system, it has already helped them start to make informed decisions with their flock.

Selection process

Their selection process starts after weaning in mid-August when all crossbred and horned ewe lambs are identified and separated.

These animals go on to winter grazing in early December. On their return at the end of February, the ewe lambs are further drafted based on size and any feet problems etc. Ewe lambs less than 30kg liveweight are not kept for breeding.

Faecal egg counts samples are continually taken so that worm burdens aren’t an influencing factor in choosing replacements because of poor growth.

Any undesirable traits in these lambs’ mothers would be noted and these animals would not be kept as replacements.

This year, with the EID system, Peter and Karol are initially planning to select from twin-bearing ewes as well as lambs gaining at least 250g/day across the crossbred and horned lambs.

Selection replacements on lowland farms

Paraic and Seamus McNeill – Annaclone, Co Down

Paraic and Seamus run 250 ewes and have used EID for several years. This year, it has been used to capture all data on potential replacements from birth, rather than starting at eight weeks old.

Paraic and Seamus now operate a four-stage process when selecting potential replacements with the aim of keeping replacements from Belcare cross and Texel cross Mule ewes.

Firstly, a whiteboard is used to record lambing details such as good mother, lambed by self, twins or triplets, lamb with good thrive, ewe with good milk etc.

Pariaic and Seamus McNeill are recording all aspects of flock performance from birth.

From this information, around 70 potential replacements are identified at weaning time, all of which are twins or triplets. No single ewe lambs are kept if possible.

Next, lambs weighed at eight weeks old must be gaining at least 320g/day. This is altered slightly depending on the number of lambs available.

This year, lambs drafted at weaning ranged from 30kg to 38kg with growth rates from 320g to 440 g/day.

Paraic McNeill capturing lthe liveweight gain of lambs using his EID system.

Physical traits are also a factor in choosing ewe lambs, with no terminal breeding chosen. A final draft is again taken using animals on track to reach 50kg liveweight at breeding time.

Trevor Nixon – Bellanaleck, Co Fermanagh

Trevor runs 150 Belclare cross Suffolk ewes and previously selected his replacement lambs from a report generated by Agri-Food and Biosciences Institute (AFBI) from their ‘Lambing Book’ which farmers completed at lambing time.

However, since 2020 Trevor has incorporated an EID system and will be using the eight-week weight facility to select potential replacements in future.

As Trevor lambed slightly later in 2022, this weighing has not yet been done. He also operates a four-tier system when choosing replacements.

Trevor Nixon purchased an EID in 2020 and now uses the data to select his replacements. \ Houston Green

Information is recorded on the EID system from birth, with twin or triplet lambs, mothering ability, milk, lameness etc. The top 50 ewe lambs are then chosen from their eight-week weight, then whittled down to between 30 and 40 animals based on a visual inspection for suitability.

Ewe lambs cut from the replacement group at this stage are still top-quality animals and are sold as breeding stock to repeat customers.

Finally, lambs are weighed prior to breeding and a final call made on replacements based on liveweight at this time.


It is vital to have some sort of recording system for making your ewe lamb selection policy. If genetic gain is to be made, then hard culling of problem ewes must be undertaken in conjunction with selecting the best-performing replacements. Both these approaches are vital to genetic improvement and breed profitable sheep.

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