Page 10 - DVAuction Online Catalogs

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Genetic Defects and IBEP Bulls
Currently, six lethal genetic defects which have DNA tests are being tracked by breed
associations. Arthrogryposis Multiplex (AM), formerly called Curly Calf; Contractural
Arachnodactyly (CA), formerly called Fawn Calf; and Neuropathic Hydrocephalus (NH) are
found in Angus cattle. Osteopetrosis (OS) is found in Red Angus cattle. Pulmonary Hypoplasia
with Anasarca (PHA) and Tibial Hemimilia (TH) are found in Shorthorn and other breeds. The
Angus Association also tracks the Myostatin nt81 Gene Deletion (M1), also known as Double
Muscling, although that is not a lethal condition.
In the IBEP 2012 Winter Test, bulls had their status checked by their breed association.
Any bulls which were potential carriers, or had unknown ancestry and were considered to be
from a risk population, were tested to determine their genotype for the appropriate traits.
All bulls are identified in one of six ways, with an AM, CA, NH, M1, PHA, TH, and/or
OS suffix appended to their registration number.
Suffix: Means this:
AMF, CAF, NHF, M1F,
OSF, PHAF, and/or THF
Bull has been DNA tested and is free of that defect. The bull
can be used with no risk of the defect.
(no suffix appended) Bull is not a descendent of a known carrier, or his immediate
ancestors have been tested free of that defect. The bull is not
suspected to carry the defect and can be used for breeding with
no increased risk of the defect.
AMC, CAC, NHC, M1C,
OSC, PHAC, and/or THC
Bull has been DNA tested and is a known carrier of that defect.
The defect will be transmitted to 50% of calves, so use with
caution especially if replacements will be kept.
AMP, CAP, NHP, M1P,
OSP, PHAP, and/or THP
Bull is from an impacted family, and therefore a potential
carrier, and has been DNA tested, but the test results are not yet
available.
AMNT, CANT, NHNT,
M1NT, OSNT, PHANT,
and/or THNT
Bull is from an impacted family, and therefore a potential
carrier, but whose owner chose not to have the bull DNA
tested.
AMRP, CARP, NHRP,
OSRP, PHARP, and/or
THRP
Bull’s non-Simmental ancestry is unknown, and therefore is
considered to be from a risk population for that lethal defect
(coded “yellow” by the American Simmental Association).
The risk of using the bull is unknown. He would need to be
DNA tested before progeny can be registered by the ASA.
All bulls in the IBEP sale are AMF, CAF, NHF, M1F, OSF, PHAF, THF or have no
carrier ancestors for AM, CA, NH, M1, OS, PHA, or TH.