Click here for two really useful links AHDB Buying a recorded ram for maternal traits also Using EBV's as a Tool to Breeding Better Sheep.
In the publication "Buying a recorded ram for maternal traits" I have a mention and a photo on page 5 of the booklet.
Modern performance recording is based on the statistical called best linear unbiased prediction (BLUP). It was developed by Professor CR Henderson of the Iowa and Cornell universities in the late 1940s, but has only become a widely used tool with the advent of modern powerful computers.The "clever" capabilities of this technique is that it can rank animals in a breeding population for different traits over different locations, different years and can take account of environmental differences over time as well as relationships between individuals regardless of current location. The more data that is included in the evaluation, including back relationships, the more accurate evaluations become.
If you were a dairy farmer would you buy semen, a dairy bull or a replacement female without performance figures? The answer to that I'm sure would be an unqualified NO.
The question then is why do so many sheep farmers buy unrecorded breeding stock? The answer to this is that performance is not measured on most sheep farms, while all dairy farms record some performance data, especially their output data. They can see the effects of improved genetics on output and costs and therefore are a lot more aware of the benefits it brings. Sheep farmers cannot easily observe their performance data unless they go to considerably more inconvenience and cost. But this does not mean they should disregard performance recording data in their buying decisions instead they should embrace it. Just look at the dairy farmers who tried the "stand still" strategy, they have all gone!
If you are interested in a maternal breed of sheep such as the Lleyn, you stand to gain even more from the adoption of ebvs and performance recorded stock purchases, as compared to a traditional cross bred ewe with terminal sire system, as the benefits multiply with each generation of the sheep you retain. The benefits will be in both ewes and lambs and this will lead to more pounds in the bank.
As a Lleyn breeder we will have data on and record for:-
Growth rates, in the form of eight week weights and scan weights.
Maternal Ability, which includes milking ability.
Prolificacy as litter size ebvs.
Mature size. Which can be used to control efficiency as well as actual size.
Muscle and back fat scanning.
To do this we record for Signet, Birth weight, 8week weight, Weaning Weight, 21 week weight, deaths and on the genetically important sheep muscle and back fat depths and individual faecal eggs counts and saliva IgA concentrations.
This results in 16 estimated breeding values plus an index which is derived from a calculation of the ebvs (but not all of them), which all our Lleyns for sale have.
It must be remembered that Signet is only half of the equation in breeding a superior performance sheep. Practical traits must also be recorded, which we log on our FarmIT3000 software along with the data for Signet. These traits include:-
Ease of lambing.
Susceptibility to Lameness/Footrot.
Susceptibility to prolapsing at lambing.
Natural Mothering Ability ( not to be confused with Maternal Ability, though there is some overlap).
Get up and go of lambs at birth.
Incidences of mastitis.
Length and body type (including wool type).
Any sheep not conforming to the highest standards are culled for meat.
This is how you make genetic progress.