Breeders need to take action during the mating season to keep the flocks linked. That means that the decisions made now will impact the 2027 flock linkage.
Any LambPlus breeder accessing their Homepage will find the Linkage status on the left of the screen, and also in the EuroStar profile.
Flock linkage refers to the genetic connectivity/relatedness between flocks. Providing accurate €uroStars (genetic evaluations) to a performance recording flock is only possible if the flock in question is genetically ‘linked’ to others. Genetic linkage is crucial for accurate genetic evaluation as it allows for fair and accurate comparisons between flocks.
Every year in May, after completion of the lambing registrations, linkage status is updated for all LambPlus flocks.
There are three possible categories of linkage status;
Linked: The ideal situation for performance recording flocks. Your flock is being compared to all other performance recording flocks within your respective sheep breed.
Weak Linkage: Your flock linkage status is weakening. You should act during the current mating season to prevent your flock from becoming unlinked. Also Flocks that shared rams only with a second flock but not with a third, will get the Weak Linkage status and it will last for the current season.
Unlinked: Your €uroStar evaluations are within flock evaluations and are not comparable to other breeders within your respective sheep breed. This will be reflected in how your €uroStars will be displayed for the season ahead. You should act during the current mating season to become linked.
How do I know if I am linked or unlinked currently?
Breeders can go to their personal Sheep Ireland online account and view their linkage status at the top of the homepage or in the Eurostar profile report.
How do I link my flock?
Flocks are linked by sharing rams with other LambPlus flocks during the same breeding season. To establish this link, the resulting lambs must be weighed at the recommended times. While more linked lambs improve the connection, a minimum of five live lambs is recommended, all of which should be weighed as required.
To maximise your flock’s linkage status, retain female lambs sired by the linkage ram where possible. Typically, once a flock is linked to an already linked flock, the linkage will remain in place for three years. Linking to a flock that is not already linked will result in a weaker linkage, which generally lasts for one year only.
Where possible, use more than one sire each year. This improves flock linkage and helps the evaluation accurately distinguish between the effects of genetics and flock environment on lamb performance.
Unlinked flock €uroStars
Flocks that are unlinked essentially only receive a within flock evaluation. Unlinked flocks are not being compared to any other flocks within their respective breed. In turn, once these flocks/animals become linked they are likely to see fluctuations in their evaluations (as they can now be compared to other flocks) which is not desirable by anyone and the best way to avoid this is to remain linked at all times.
How do I become a linked flock?
To link with another flock, the same sire (genetics) must be shared by two LambPlus breeders in the same breeding season. As stated above weights must subsequently be recorded from the shared sire’s progeny in both flocks. Breeders should aim to produce at least 5 live lambs from the ‘linkage’ sire being used.
There are several options available to you to become linked;
Use Artificial Insemination (AI) on a number of your ewes, ensure that you are using semen that is also being used by at least one other linked LambPlus breeder. Again, ensure progeny are subsequently weighed in both flocks. From a biosecurity perspective, this is the safest option to become linked. Contact your sheep breed society for advice on carrying out AI.
Share a sire with another linked breeder in the same year, and ensure progeny are subsequently weighed in both flocks. Warning – breeders should be fully aware of the biosecurity risks associated with sharing rams with other flocks. It is advised that you carefully consider all risks before making any decision in this regard.
Temporarily move a number of ewes to a linked flock at mating time to allow them to be mated by a linked sire. Again, breeders should be fully aware of the biosecurity risks associated with this type of approach.
Purchase inlamb females from a linked flock. Ensure the source flock will also have progeny from the sire used across the inlamb ewes. Again ensure progeny are subsequently weighed in both flocks. Warning – breeders should be fully aware of the biosecurity risks associated with purchasing inlamb ewes (or any sheep) from other flocks. It is advised that you carefully consider all risks before making any decision in this regard.
Central Progeny Test (CPT)
The Sheep Ireland CPT was established in 2009 and its main function was to fast track and maintain genetic linkage among performance recording flocks in Ireland. It carries out this function by bringing together influential bloodlines across the most widely used sheep breeds in Ireland and using them together across commercial ewes contracted by Sheep Ireland to carry out intensive performance recording.
How does linkage work?
In the example below Link Ram 1 is the most connected ram as it has been used in most flocks including the CPT, this ram is likely to have the highest accuracy, meaning his evaluation will be more dependable.
Home Ram A, B, C & D have all only been used in one flock but are still linked because a second ram has also been used in the flock and that second ram has also been used in another linked flock.
Home Ram F is not linked, therefor the lambs in this flock will not be linked and the data collected in this flock will be of limited use in the evaluation.
What will happen if my flock remains unlinked?
Unfortunately, for unlinked flocks, the genetic evaluation information available to ram purchasers is severely compromised. With this in mind, Sheep Ireland has a responsibility to highlight unlinked flocks where genetic evaluations are available to the public – €uroStar sales catalogues, the online ram search etc.
Stars for linked and weak linked flocks will be displayed as normal as seen below.
Stars for unlinked flocks are displayed as below (no fill colour)
and with the message “Within flock evaluation”:
– If I am an unlinked flock, will my rams be eligible for the Sheep Improvement Scheme (SIS)?
If they accomplish the criteria, rams from unlinked flocks will be eligible for the SIS.