HD breeding value

The correct answers to the most frequently asked questions

In order to have the breeding value rated where can I bring my dog to? Or, which breeding value is the better one, more than 100 or less than 100? These are the HD breeding value questions which the main office is asked consistently for.
Therefore, we collected the most frequently questions and had them responded for you from Dr. Beuing, the scientific leader of the project.

1. How is the breeding value for my dog calculated? What is the used formula?

There is not quite a formula for calculating the breed value. In the beginning, the breed value of each animal is considered to be unknown, in the form: HD = breed average + breed value of this animal + bias of gender + other effects. In this equation the breed average, the breed value and the effect of the gender are verbalized as reason for HD. In SV, for 450.000 dogs 450.000 equations are formed with the 450.000 unknown breed values. Afterwards, some additional conditions about laws of heredity and heritability are verbalized mathematically. Following, the computer has to resolve the 450.000 equations with the 450.000 unknowns. The results are the estimated breed values. Therefore, a formula to calculate the breed value for a separate dog does not exist.

2. How decisive is the HD rating of my own dog for its HD breeding value?

The dog HD-level modified what we already knew about the lign (father and mother). Siblings (same father and same mother) are differenciated by a possible HD-level diffrence. When an animal have an offspring, the own HD-Level loses its importance. With 30-40 offsprings, it almost doesn't matter anymore.

3. How is a foreign “a” rated for the HD breeding value?

Foreign dogs with an "a" will be at the moment so valued, as if they were not x-rayed. Their breed value only results from the checked relatives. The animals that are not clearly certifiable as "free" or "still permitted", would be unfairly accepted in an individual case.

4. Why can a dog which has not been x-rayed itself have a HD breeding value?

There is a constraint in the system of equation (cf. answer of question 1), that the father (and the mother) pass on half of his/her hereditary characteristics to the offsprings. If we do not know anything about the animal (no x-ray) as long as the breed value of the father and the mother is known, from there the breed value of the offsprings can be estimated. A precise assessment of the parents can be made, if the offsrings are known, then the offsprings have half of the parents hereditary characteristics. On the one hand, siblings help to characterize the parents, on the other hand, the knowledge about the parents breed value help as well to assess the unchecked siblings breed value.

5. How accurate can the HD breeding value be when for more than half of the puppies per year no HD rating is on file?

For the breed value calculation does not count the percentage of puppies but the absolute number. At present, the Bundessieger 2019,Willy vom Kuckucksland, has 368 x-rayed descendents; they characterize his inheritance very well.

6. Until now, my female passed the “a“ good on. What happens when I breed her with a male with a HD breeding value of more than 100?

When the female passed on well, her breeding value has to show this. However, good offspring can also result of good mating. For example, when the female has been bred to a male with 100 the risk for the puppies increases. The female is only compromised when the puppies are worse than it had to be expected with this male.

Generally, one can say that the sire’s owners are well advised to accept also more “worse“ females because when the females are worse the male can proof that he improves.

Because there is no better HD rating than HD free is not difficult to show a positive heredity transmission with top females.

7. How are dogs without HD rating integrated into the calculation of the HD breeding value?

At present, for the breeding value animals which have not been x-rayed are “neutral”; they are elided.

8. What means the average breeding value 100 and the standard deviation of 10 points as mentioned in the breeding plan?

The breed value 100 means that the aminal passes on typical for the breed. Currently, the average of the breed is 1.71, this is between HD free and slight HD. The inheritance can be better or worse than 100. The average deviation top down is adjusted to 10 points medium.

9. What does a breeding value of 100 mean for my dog?

A breed value of more than 100 for the own dog means that the dog passes on detrimental. Because the average of the breed is still not entirely satisfying breeding should be preferred when it results lower than 100. However, the baby may not be thrown out with the bath water. First priority is performance, character etc. Using a breeding male who pushes the average to under 100 is sufficient.

10. On the opposite, what does a breeding value of less than 100 for my dog?

A breed value lower than 100 means that you have much tolerance to select males of good performance and exterior, also if their breed value is more than 100. When the female has a breed value of 83 the male can be accepted also with a breed value of 117!

11. Can a breeding value also be calculated for other criteria than HD and, if yes, for which?

A breeding value can also be calculated for other characteristics. However, it is important to specify the characteristic exactly. Next is contemplated to describe the heritage of size. This breeding value will be just for the information of the breeder; there will be no requirements concerning this matter.

Dr. Reiner Beuing
University of Gießen