PATB
Well-known member
copied from Advantage cattle service site
Subject: Important communication to AGA members regarding genetic defects
This communication is to inform you of the confirmation of a registered,
purebred Gelbvieh animal possessing an inherited genetic defect called
Contractural Arachnodactyly (CA). The more common name for the defect is
"fawn calf". In an effort to keep you informed, what follows are a few
details pertaining to this case as of today.
What we know today:
- Over the past few weeks, AGA staff have been monitoring the report of a
yearling bull that DNA tested "affected" with Contractural Arachnodactyly
(CA), a genetic defect more commonly know as "fawn calf". Follow-up testing
of the parents of the CA affected (CAA) animal confirmed that they are both
CA carriers (CAC). The maternal great-grandsire of the dam of the CAA animal
is a known CAC Angus bull, Bon View Bando 598. Therefore, no more testing
was needed on the dam's side of the pedigree. All parties associated with
the CAA calf were notified immediately.
- The sire of the CAA animal is 43U (AMGV1063542). The next step was to
test the sire and dam of 43U. DNA test results received on May 28, 2013
revealed that DCSF Post Rock Granite 200P2 (AMGV930426) is a CA carrier.
43U's dam, Skylin (AMGV943109) tested CAF. The owners and breeder of DCSF
Post Rock Granite 200P2, and the primary distributer of his semen have been
notified.
The next steps:
- DNA testing the parents of Post Rock Granite 200P2 has been initiated.
We expect those results by June 11.
- Testing will continue as far back into the pedigrees of the carrier
animals as possible
- The AGA Board will consider policy changes regarding A.I. sires and
calves resulting from E.T. Current AGA policy does not require CA testing of
sires and dams in order to obtain A.I. and E.T. permits, respectively.
- The AGA membership will immediately be informed of any future
developments or policy changes.
Why did it take so long to see a CAA animal in purebred Gelbvieh?
- The Angus breed is the source of CA. This, coupled with the fact that
Angus have been used in the development of purebred Gelbvieh, made it
possible for the CA gene to exist undetected in purebred Gelbvieh, at a very
low gene frequency.
- In addition, only 1 in 4 calves resulting from the mating of two CAC
parents will result in a CAA progeny.
- CA is not a lethal genetic abnormality and can be somewhat difficult to
detect, particularly in older animals. Therefore some CAA animals may go
undetected.
What is Contractural Arachnodactyly (CA)?
- CA is inherited as a simple recessive, meaning that carrier animals (CAC)
will appear normal. An animal must possess two copies of the CA gene in
order to express the CA defect.
- CA affected (CAA) new born calves are born alive and most can nurse and
survive. However, they typically have restricted limb movement and will
often have an abnormal posture resembling an elk or deer fawn. As CAA
animals get older, detection of the defect is more difficult, although they
typically appear taller and more slender than their CAF siblings and do not
perform as well as their contemporaries.
How accurate is the DNA test for CA?
. Over 75,000 animals have been DNA tested for CA since the test was first
developed in 2010.
. Today, the DNA test for CA is nearly 100% accurate. Gelbvieh breeders can
use the CA test with confidence.
. Due to the very low incidence of CA in the Gelbvieh breed, there is a 50%
probability that the mating of a CAC sire to an unrelated Gelbvieh female
will result in a CAC progeny.
. It is recommended that progeny of a CAC parent be tested for CA. DNA
testing order forms can be found on the AGA website.
http://www.gelbvieh.org/education/dnatesting.html
Please contact the AGA office (303-465-2333) if you have questions.
Sincerely,
Jim Gibb
Executive Director
American Gelbvieh Association
Subject: Important communication to AGA members regarding genetic defects
This communication is to inform you of the confirmation of a registered,
purebred Gelbvieh animal possessing an inherited genetic defect called
Contractural Arachnodactyly (CA). The more common name for the defect is
"fawn calf". In an effort to keep you informed, what follows are a few
details pertaining to this case as of today.
What we know today:
- Over the past few weeks, AGA staff have been monitoring the report of a
yearling bull that DNA tested "affected" with Contractural Arachnodactyly
(CA), a genetic defect more commonly know as "fawn calf". Follow-up testing
of the parents of the CA affected (CAA) animal confirmed that they are both
CA carriers (CAC). The maternal great-grandsire of the dam of the CAA animal
is a known CAC Angus bull, Bon View Bando 598. Therefore, no more testing
was needed on the dam's side of the pedigree. All parties associated with
the CAA calf were notified immediately.
- The sire of the CAA animal is 43U (AMGV1063542). The next step was to
test the sire and dam of 43U. DNA test results received on May 28, 2013
revealed that DCSF Post Rock Granite 200P2 (AMGV930426) is a CA carrier.
43U's dam, Skylin (AMGV943109) tested CAF. The owners and breeder of DCSF
Post Rock Granite 200P2, and the primary distributer of his semen have been
notified.
The next steps:
- DNA testing the parents of Post Rock Granite 200P2 has been initiated.
We expect those results by June 11.
- Testing will continue as far back into the pedigrees of the carrier
animals as possible
- The AGA Board will consider policy changes regarding A.I. sires and
calves resulting from E.T. Current AGA policy does not require CA testing of
sires and dams in order to obtain A.I. and E.T. permits, respectively.
- The AGA membership will immediately be informed of any future
developments or policy changes.
Why did it take so long to see a CAA animal in purebred Gelbvieh?
- The Angus breed is the source of CA. This, coupled with the fact that
Angus have been used in the development of purebred Gelbvieh, made it
possible for the CA gene to exist undetected in purebred Gelbvieh, at a very
low gene frequency.
- In addition, only 1 in 4 calves resulting from the mating of two CAC
parents will result in a CAA progeny.
- CA is not a lethal genetic abnormality and can be somewhat difficult to
detect, particularly in older animals. Therefore some CAA animals may go
undetected.
What is Contractural Arachnodactyly (CA)?
- CA is inherited as a simple recessive, meaning that carrier animals (CAC)
will appear normal. An animal must possess two copies of the CA gene in
order to express the CA defect.
- CA affected (CAA) new born calves are born alive and most can nurse and
survive. However, they typically have restricted limb movement and will
often have an abnormal posture resembling an elk or deer fawn. As CAA
animals get older, detection of the defect is more difficult, although they
typically appear taller and more slender than their CAF siblings and do not
perform as well as their contemporaries.
How accurate is the DNA test for CA?
. Over 75,000 animals have been DNA tested for CA since the test was first
developed in 2010.
. Today, the DNA test for CA is nearly 100% accurate. Gelbvieh breeders can
use the CA test with confidence.
. Due to the very low incidence of CA in the Gelbvieh breed, there is a 50%
probability that the mating of a CAC sire to an unrelated Gelbvieh female
will result in a CAC progeny.
. It is recommended that progeny of a CAC parent be tested for CA. DNA
testing order forms can be found on the AGA website.
http://www.gelbvieh.org/education/dnatesting.html
Please contact the AGA office (303-465-2333) if you have questions.
Sincerely,
Jim Gibb
Executive Director
American Gelbvieh Association