Changes to Evaluation Release - Corrected Cow Evaluations, February/March, 2005


Corrected Cow Evaluations:

By Paul VanRaden

A change in the distribution of elite cows across states, noticed by Jersey breeders, was traced to a bug introduced in the February evaluations, with the adjustments for inbreeding. These adjustments are applied separately to different groups of animals (superherds) because of computer memory limitations. PTAs were correct for bulls and cows with progeny in more than one superherd, and for all animals in the first superherd. When animals in later superherds were processed, the expected future inbreeding (EFI) used to adjust the PTA was not from the right animal.

This error did not affect Brown Swiss, Guernsey, Ayrshire, and Milking Shorthorn PTAs because these breeds do not require more than one superherd. Small changes in some evaluations for these breeds were due to rounding differences and the use of Interbull type data which was not available at the time of regular run calculations. PTAs were correct for Holstein and Jersey bulls except those with very limited geographic sampling. Six active AI bulls were affected as listed below. PTAs of most Holstein cows changed by about 20 NM$ because the incorrect EFI was from another cow of the same birth year. However, some Holstein cows in California, Puerto Rico, Hawaii, and Alaska (the last superherd) changed by up to 100 NM$ because incorrect EFI was not from the same birth year. Jersey cow PTAs were correct in states with numbers 11 to 73 (the first superherd) but incorrect in higher numbered states (listed below), with maximum error of about 150 NM$ (changes averaged about 40 NM$).

AIPL apologizes for this coding mistake and thanks Jersey breeder Wayne Woods of Tillamook, Oregon for noticing a discrepancy between PTA, parent average (PA), and daughter yield deviation (DYD), and reporting this to Cari Wolfe at The American Jersey Cattle Association. This information was very helpful in locating the problem. Also, Tom Lawlor of Holstein USA noticed that the yield deviations reported for cows were adjusted to inbreeding of zero instead of to EFI, which has also been corrected. The largest PTA corrections were for 500 cows born by embryo transfer (ET) whose dams were accidentally deleted from February calculations due to a change in data editing routines. The EFI coding mistake was detected on March 7th and corrected files were provided on March 14th.


Active AI bulls affected:

JEUSA000111287598 LUCKY 122JE05193

JEUSA000111257364 STEALTH 011JE05191 122JE05191

HOUSA000127842310 SUPERB-RED 100HO09403

HOUSA000129664686 BOOSTER 151HO00381

HOUSA000017246613 COLECO 049HO01798

HOUSA000002201166 LEADER 076HO00135


States affected for Jersey cows:

Alaska (96), Arizona (86), California (93), Colorado (84), Hawaii (95), Idaho (82), Montana (81), Nevada (88), New Mexico (85), Oregon (92), Puerto Rico (94), Texas (74), Utah (87), Washington (91), Wyoming (83).