What is needed to calculate accurate EBVs?

EBV accuracy is impacted by the amount of data on the individual and its relatives. The closer the relationship, the greater the impact. Below are five recommendations for you to be able to benefit from accurate EBVs.

1. Lots of data for a specific trait within your breed:

Ideally, this is hundreds of dogs of a particular breed. Our most accurate EBVs are calculated on Labradors, Golden Retrievers and German Shepherds – these are breeds that have been bred by service dog organizations who have been reliably inputting data for years.

With time and consistency, EBVs can be developed for other breeds. The use of EBVs is ideal for breed clubs or breeds which need to resolve a particular health issue, but improvement requires a dedicated group who are willing to track generations of data for particular traits within their breed.

2. Extended pedigrees entered in IWDR to tie dogs together:

5 generations is a general guideline and a good place to start. Our EBV calculations are done within our database, the International Working Dog Registry. 

3. Data on all or most dogs in the population, not just the breeders:

Health clearance data on only certified dogs is not useful! The dataset must contain all measures – the good and the bad.

If you only track the best dogs in your program, your EBVs will look amazing, but will not be accurately reflected in your program. Keeping in touch with clients/owners throughout the life of the dog is helpful. IWDR users can consider our Health Survey as a method to achieve regular health touch-points.

4. Take consistent measurements:

Make sure you use the same method of measuring your dog’s traits, or use measurement methods that are correlated. For behavioural traits in guide/service dogs, we recommend the Behavior Check List or similar. This is a good example of an assessment with consistent measurements.

Make sure measures are taken for each dog at similar age brackets, if age impacts expression of the trait. 

5. Take accurate measures:

Particularly in behavior assessments, make sure to use skilled scorers with adequate inter-rater reliability. The test needs to be run correctly and in a similar (or the same) environment for each dog. You should also use validated measurements.  For behavioural traits in guide/service dogs, we recommend the Behavior Check List or similar. This is a good example of an assessment with thorough descriptions of behavior to allow for accurate scoring.

In the chart below, the organization owning these studs obtains extended view and elbow quality measures on all puppies who have been raised in the puppy program. The accuracies are high for these traits. However, in most cases, only the breeders have PennHIP measures which provides fewer phenotype measures for the EBV software and therefore, lower accuracy. Keith has no progeny and his parents and other close relatives did not get PennHIP measures. The accuracy is so low that no EBV ranking for PennHIP displays.