EBVs describe the difference, not the actual

EBVs are a powerful tool to support breeders when making breeding and selection decisions. It is however important when utilising EBVs that we understand the tool and what information it provides, to assist with decision making.

EBVs describe expected differences between the average performance of progeny and do not describe the performance we can expect from the individual animal, for whom the EBVs have been calculated.

So why can’t we look at a bull’s physical performance and use this to validate his EBVs?

Well, the first issue is that the physical performance of the bull is significantly impacted by the environment in which he was raised. These environmental factors are non-genetic and therefore cannot be passed on to his progeny. EBVs take out these non-genetic factors in their calculation and this is why the breeding value produced is an estimate of the animal’s genetic merit.

Check out next week’s edition of e-news for the second reason why EBVs describe differences and not actual.