We are a Registered Merino Stud operating a large commercial flock.  

Latest SHEEP GENETICS genetic trend report for Ruby Hills view pdf

Our aims are to breed:

• Long ,  Bright,  17 to 17.5 micron wool of high tensile strength
• Robust Sheep, producing high fleece weights with minimal chemical inputs for internal/external parasites.
  

In order to achieve this we are placing emphasis on using measurements of genetic rather than phenotypic performance.  In recent years we have come to appreciate the value of using Estimated Breeding Values(EBV) to assist selection of both stud and flock rams.

EBV’s aim to determine an individual sheep’s true genetic merit. The figure is derived by considering the performance not only of an individual sheep, but all its known relatives as well. If enough related information can be accumulated, environmental or non-genetic effects can be eliminated.
 

 
The graphs demonstrate the progress we have made in the four traits: Clean Fleece Weight (CFW); Fibre Diameter (FD); faecal egg count (FEC); and Staple Strength (S/S).

Environmental effects that impact on performance have clouded past efforts to establish an index based selection system, aimed at achieving heavier cuts and finer wool. Factors such as paddock and seasonal differences; the effect of twin status; and errors in sampling, tag reading, and measurements all need to be removed from the genetic equation. Subjective perceptions of style, (such as crimp frequency) have also influenced some efforts.

It is not surprising progress has been slow in index based selection systems if we end up selecting traits that have little or no genetic basis.

EBV’s can offer a clearer genetic picture. We originally used EBV’s to help with breeding more worm resistant sheep but it soon became clear they were useful in determining other traits as well.
This system has worked particularly well at Ruby Hills. All our stud matings are single sire and most new introductions are compared to sires already in the stud. And this means genetic trends can be separated from their environmental influences (such as drought) and that we can track our progress through time and not be confounded by the effects of the seasons.