10.6 Confirmation of parenthood

In many breeding associations the mating needs to be confirmed by DNA test when the offspring is born. Important reason is to protect the quality of the pedigree recording. There are a number of reasons why pedigree recording may be of poor quality:

1. In some group mating systems (e.g. fish) where multiple males are females are housed together. The exact pedigree of offspring will only be revealed after DNA check.

2. When many offspring are born on (approximately) the same day, tagging of the animals is not always done vary accurately and the tag with pedigree registration for one animal may end up on the wrong animal.

3. In large pasture systems (e.g. in New Zealand) of dairy cattle, where the cows have been inseminated with different bulls in a period of six weeks, it is not always clear which calf belonged to which cow after the daily collecting the calves born without supervision at the pasture. In that case both parents are uncertain and parentage needs reconstruction based on what information is available on the DNA of each of the parents.

4. When matings fail females are mated again. Sometimes to the same male, sometime to another male. As sperm may survive in the female for some time, a DNA test will reveal which male is the father.

5. At the start of a breeding program, when little or no pedigree is available. An extensive DNA test (large SNP set for example) can be used to test how related two animals are with incomplete pedigree.

6. To discourage false matings. Especially in situations where the actual mating is expensive, the owner of the male may be tempted to use an alternative when the number of matings is exceeding the potential of the male. Or when the fertility of the male is insufficient. Especially in the past, before the DNA test became available, some of these practices did occur in horses.