The Full Story Behind W/C Wide Track 694Y
By Jackie Atkins, The American Simmental Association and Lindsay Johnson, Genex
This spring, a high-impact Simmental bull, W/C Wide Track 694Y, was erroneously named a carrier of Contractural Arachnodactyly (CA), also known as fawn calf syndrome. After further investigation, it became clear that Wide Track was in fact free of the defect. What happened to lead to such a monumental mistake? Here is the full story from American Simmental Association (ASA), Genex Cooperative, Inc. and the Werning family.
As part of an effort to screen the most-used bulls in the ASA registry, the ASA in collaboration with Genex, Accelerated Genetics, Select Sires and Allied Genetic Resources, sent in samples on all SimGenetic bulls available through these companies for extended genetic condition testing. On April 16, 2015, the ASA received results on 249 sires tested for the following conditions:
AM = Arthrogryposis Multiplex, a.k.a. Curly calf (Angus)
DL = Dilutor (Hereford)
IE = Idiopathic Epilepsy (Hereford)
NH = Neuropathic Hydrocephalus, a.k.a. water head (Angus)
OS = Osteopetrosis, a.k.a. Marble bone disease (Red Angus)
PHA = Pulmonary Hypoplasia with Anasarca (Shorthorn and Dexter)
TH = Tibial Hemimelia (Shorthorn)
HY = Hypotrichosis (Hereford)
CA = Contractural Arachnodactyly, a.k.a. Fawn calf (Angus)
DD = Developmental Duplication (Angus)
One bull, W/C WIDE TRACK 694Y (ASA # 2588250), was reported a CA carrier. Dr. Jon Beever conducted further testing on the original sample (two additional tests) and concluded the sample was in fact a carrier of CA. Wide Track had an Angus cow, of unknown pedigree, four generations back in his pedigree making it unlikely, but feasible, that he carried the CA gene. As the dam and sire of Wide Track did not have DNA on file, the Wernings sent in samples for parent verification and CA testing to both Dr. Beever and GeneSeek.
In the meantime, Genex pulled Wide Track from their lineup. Announcements were sent out from Genex (April 20) and ASA (April 26) to notify their members.
“For those Genex members and customers who had purchased Wide Track semen within the past 24 months, Genex issued a credit for any semen that hadn’t been used,” states Willie Altenburg of Genex Beef Genetics.
During that same time, the Werning family pulled Wide Track from the herd and made the decision to have him put down.
“We don’t believe in using a carrier bull so didn’t see any value in keeping him around,” states Scott Werning, Werning Cattle Company. “We realized there was the potential for him to sire clean calves; however, we didn’t want to be known for propagating the defect. We knew putting him down was the right thing to do.”
On May 6, Dr. Beever notified ASA and Genex that neither of Wide Track’s parents were carriers of CA. This is not possible unless 1) the original CA report was wrong or 2) the parentage was wrong. Dr. Beever isolated a new sample of DNA from Wide Track which tested free of Contractural Arachnodactyly. Dr. Beever then obtained a new straw of semen from Genex and tested that sample. Again, the sample came back CA-free. On May 8, Genex and the ASA announced that Wide Track was indeed CA-free and the original testing was an error. The reported parentage was confirmed with GeneSeek on May 15, 2015.
“When we learned Wide Track was CA-free, many customers, who had received credit for Wide Track semen, used that credit to purchase more Wide Track semen,” states Altenburg. “That tells you how well our customers like the bull. Today, a limited amount of Wide Track semen is still available from Genex.”
The obvious question is, “Why was the original sample positive?” The simple answer is we still don’t know. All the samples in the same order were retested twice and all came back free so there was not a simple swap. It is unclear how the original sample was contaminated; but, there is no doubt that Wide Track is free of these 10 genetic conditions.