Sources of information for breed/crossbreed averages for important traits
Some progress has been made, to compile well designed look-up tables that allow a reasonably reliable comparison of differences between breeds, however they are not currently available for the full set of breeds and traits that impact on enterprise profit.
Multibreed EBVs
The first multibreed EBVs were released last year for four breed groups – Angus, Poll Hereford, Limousin and Simmental. This means that for the first time we can compare bulls and females directly across these breeds, whereas previously it was only possible to compare the EBVs within breeds. At this stage it is possible to do this for gestation length, liveweights up to 600 days and carcase weight.
Table 1 presents the adjustment factors that need to be used to make direct comparisons possible across the four breeds.
Table 1: Multibreed EBV adjustment table (March 2003)
Table 1 provides estimates of the genetic differences between these breeds for the traits mentioned, using Angus as the baseline.
All that is needed to produce multibreed EBVs for a given trait, is to add to an animal’s existing within breed EBV to the value listed in Table 1 for that breed. For example, to compare an Angus bull with an EBV for carcase weight of +33, with a Limousin bull that has a within breed EBV of +16, we have:
Angus bull with a value of 0 [from Table 1]+ 33 = 33
Limousin bull with a value of 20 [from Table 1]+ 16 = 36
So for the two bulls in this example the Limousin bull has an advantage of + 3 for this trait.
