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.”
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