The Cow Control Number is used to detect when a cow's ID has changed. Because control numbers are reused, pedigree, termination codes, and calving dates are checked to avoid combining data from different cows.

Lactation records are checked as follows: Several new error codes have been assigned to report on this process:

1O Conflicting ID with same herd and cow control number, no cross reference.
1O Conflicting twin, ET, or clone ID with same herd and cow control number. Lactations were merged. Separate pedigrees remain.

2K Conflicting ID with same herd and cow control number; sire ID is different. No cross reference.
2K Conflicting ID with same herd and cow control number; sire ID is different. Cross reference is needed for sires. Cow was cross referenced.

3K Conflicting ID with same herd and cow control number; dam ID is different. No cross reference.
3K Conflicting ID with same herd and cow control number; dam ID is different. Cross reference is needed for dams. Cow was cross referenced.

5K Conflicting ID with same herd and cow control number; lactations will not merge. No cross reference.

For now, these errors cause a Notify. After we gain experience with this edit, we intend to reject the incoming record in some of these cases.

Some existing codes are generated during the control number processing:

1C A cross reference has been generated because of matching cow control numbers.

4F A birth date has been changed because of a small difference in birth dates encountered when applying a cross reference generated from matching control numbers.